VOLCANO NEWS
Updated on 8th of May 2010 (latest news classified
according to countries)
Highlight today :
eruption at the Eyjafjallajokull is still continuing
- Iceland
(read report below) -
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ECUADOR -
Guagua Pichincha volcano
April
18th , 2010
As of the
17th of April 2010, IG reported that there no change, both the
seismic activity and fumarole emission remained at a low level.
Previous significative information : as of the 20th of February
2009, IG reported that the seismic stations Geophysical
Institute have registered for days back a slight increase of the
internal activity of volcano Guagua Pichincha. In previous days
4 phreatic explosions of moderate size have been registered.
These explosions happen due to an increase of the internal steam
pressure, possibly related to the increase of precipitations
observed in the zone of volcano. Therefore the Geophysical
Institute recommends that it is not allowed to descend to the
interior of the crater since the phreatic explosions could be
repeated and the people could take the rock hit, other materials
and/or rarefaction waves that are generated by these events.
These phreatic explosions they happen generally at times of much
rainfall, this is the reason why these explosions not
necessarily are indicative of a substantial increase of the
activity of volcano Guagua Pichincha. The Geophysical Institute
in its preprecautionary eagerness of the security of the people
maintains a monitoring permanent of the state of this and other
volcanos of the country and will inform opportunely into any
change that these can present/display. The activity of the
volcano shows a slight increase in its seismic activity with
respect to the previous months. 40 volcano-tectonic (VT)
earthquakes have been registered, which are related to the
fracturing of rocks to the interior of the complex between the
14th and the 18th of February. These earthquakes are of small
magnitude, which is the reason why they have not been perceived
by the population. It is possible to indicate that during the
2007, an average of 4.2 VT earthquakes per day was had. Also in
this time interval 6 events of long period (LP) per day were
registered when the average in the 2008 was of 0.3. LP events
are related to resonances of cracks full of flowed inside the
volcano. In addition it is important to mention the presence of
explosions of moderate magnitude, related to the phreatic
activity. The 16th of February the guardian of the refuge of the
volcano perceived an increase in the scent to sulphur in the
high part of the crater. Guagua Pichincha rises immediately W of
Quito, Ecuador's capital city. The broad volcanic massif is cut
by a large horseshoe-shaped summit caldera, ~6 km in diameter
and 600 m deep, that was breached to the W during a slope
failure ~50,000 years ago.
- Information
: I G Quito
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Cratère du Guagua Pichincha - Aôut 1999 -Viracucha |
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ECUADOR -
Tungurahua volcano
May 8th, 2010
As of the
7th of May, the Instituto Geofísico (IG) reported that the
activity of the volcano stayed in a level considered as low. Any
type of surface activity has not been observed. Rains registered
in afternoon of yesterday originated small to moderate lahars in
the southwestern sector of the volcano. The IG also reported
that event in the volcano has not been registered. During the
first times of the night of yesterday the volcano he was cloudy
and it was observed that the surface activity was null. In the
afternoon rains were registered yesterday that generated lahars
in the southwest sector of the volcano, especially in the gorge
of Mapayacu between the 1500 and 1600 hrs local time. As of the
30th of April, the Instituto Geofísico (IG) reported that the
activity of the volcano stays in a level considered as low. The
IG also reported that the count of seismic activity is 1 event
of long period (LP). The volcano has remained varying between
dimmed and cleared, in the afternoon of today, when the crater
remained cleared could be appreciated fumarolic activity of
little intensity. As of the 22nd of April, the Instituto
Geofísico (IG) reported that with respect to the previous days a
slight increase of the seismic activity of the volcano is
registered. The activity of the volcano stays in a level
considered as low. The IG also reported that the count of
seismic activity is 12 events of long period (LP), 2
Volcano-Tectonic (VT) and 5 episodes of small tremor of
emission. At dawn of today the presence could be observed of a
small plume of steam and gases located in western the North side
of the crater. As of the 16th of April, the Instituto Geofísico
(IG) has reported that the activity of the volcano stays in a
level considered as low. The IG also reported that with respect
to seismicity: One has entered event of long period (LP) has
been registered. Observations due to the cloudiness presence
have not been realised in the zone of the volcano. As of the 9th
of April, the Instituto Geofísico (IG) has reported that the
activity of Tungurahua volcano maintains a level of activity
considered as low. At the moment light drizzles in the sector
have been registered. One does not have reports of lahars. The
volcano remains cloudy. The IG also reported that with respect
to seismicity: One has entered 1 event of long period (LP) has
been registered, 1 episode of tremor of emission. The volcano
has remained dimmed; visual registries of the surface activity
are not had.As of the 2nd of April, the Instituto Geofísico (IG)
has reported that the activity of Tungurahua volcano stayed in a
level considered as low. The volcano remained cloudy which is
the reason why visual reports are not had. In afternoon
yesterday, light rains in the sector of the volcano appeared
that did not generate lahars. The IG also reported that with
respect to seismicity: One has entered 1 event of long period
(LP) has been registered. The volcano has remained in a storm
cloud, thus they do not have reports of its surface activity.
Light rains during the afternoon of yesterday have been
registered without having generated lahars. As of the 26th of
March, the Instituto Geofísico (IG) reported that the volcano
presents/displays a low level of activity. The volcano has
remained in a storm cloud, especially the high part, reason why
it does not have visual reports. Volcanic explosions have not
been registered. The IG also reported that with respect to
seismicity, one has registered 6 events of long period (LP) and
4 small episodes of tremor of emission and 3 small episodes of
harmonic tremor have been registered. As of the 24th of March,
the IG reported that although inclement weather often prevented
observations of Tungurahua during 17-23 March, steam-and-gas
plumes were occasionally seen. Explosions were detected by the
seismic network and heard in nearby areas on 19 March; the
largest explosion generated an ash plume that rose to an
altitude of 9 km (29,500 ft) a.s.l. Ashfall was reported in
Choglontús, to the SW. On 20 March small lahars affected the
Baños-Penipe highway. On 22 March, ashfall was again reported in
areas to the SW.As of the 19th of March, the Instituto Geofísico
(IG) has reported that the Tungurahua volcano continues
presenting/displaying a decreasing tendency of activity. The
present level of the seismic activity is moderate-low. Unique
two events of long period have been detected. Moderate rains
took place during the night that did not generate mud flows nor
lahars. The IG also reported that with respect to seismicity,
one has registered 2 events of long period (LP). LP earthquakes
are related to the resonance of flowed in the cracks of the
interior of the volcano. Generally the volcano has remained
storm cloud, which is the reason why the zone of the crater
could not be observed. Moderate rains were registered during the
night, which did not generate lahars.Tungurahua is a steep-sided
stratovolcano or a conical volcano composed of many layers of
hardened lava, tephra, and volcanic ash and is located near
Ecuador's fourth largest city of Ambato, some 140 km south of
the capital Quito.
Tungurahua -
Live webcam
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ECUADOR
- Reventador volcano
May
8th, 2010
As of the
7th of May, the Instituto Geofísico-Escuela Politécnica Nacional
(IG) has reported that the seismic activity stays in a level
considered as moderate. The zone has remained cloudy. A total of
25 events of long period (LP), 8 explosions, 7 episodes of
harmonic tremor and 9 episodes of spasmodic tremor has been
entered. As of the 30th of April, the Instituto
Geofísico-Escuela Politécnica Nacional (IG) reported that the
seismic activity stayed in a level considered as moderate.
During the morning of today a report of an emission column was
received steam with content under ash, product of an explosion.
A total of 10 events of long period (LP), 9 explosions, 8
episodes of harmonic tremor, 5 volcano-tectonic (VT) episodes of
tremor of emission and 2 events has been entered. As of the 22nd
of April, the Instituto Geofísico-Escuela Politécnica Nacional
(IG) has reported that the seismic activity of the volcano stays
in a level considered as moderate and without variations of
importance with respect to registered in the last the months,
nevertheless observations of superficial manifestations have
allowed to detect the generation of small associated pyroclastic
flows to explosive events. These pyroclastic flows are developed
and are deposited in the South flank of the volcano. A total of
14 events of long period (LP) has been entered, 4
Volcano-Tectonic (VT), 10 explosions, 8 episodes of harmonic
tremor, 9 Volcano-Tectonic episodes of tremor of emission, 3
events. In afternoon from today reports of the emission
generation were received yesterday and tomorrow and explosions
that generated small columns of steam and gases with low ash
content. Of agreement, to the reports of yesterday afternoon
could be concluded that one of the explosions generated a small
flow pyroclastic that descended by the South flank of the
volcano.A s of the 16th of April, IG reported that the level of
seismic activity of the volcano stays in a considered level as
moderate and with respect to the last months it does not
register changes of behaviour in the general activity of the
volcano. A total of 18 events of long period (LP), 20
explosions, 1 Volcano-Tectonic (VT), 11 episodes of harmonic
tremor, and 8 episodes of tremor of emission has been entered.
The sector of the volcano stays with high cloudiness.As of the
9th of April, the Instituto Geofísico-Escuela Politécnica
Nacional (IG) reported that the activity of Reventador volcano
stayed in a moderate level of activity. The volcano has remained
dimmed. A total of 18 events of long period (LP), 17 explosions,
26 episodes of harmonic tremor, 7 episodes of tremor of emission
and 1 volcano-tectonic (VT) event has been entered. The
cloudiness of the sector has prevented to realise observations
of the surface activity of the volcano. The strong rain in the
sector has appeared during the morning and behind schedule of
today; nevertheless, report of lahars is not had. Reventador is
the most frequently active of a chain of Ecuadorian volcanoes in
the Cordillera Real, well E of the principal volcanic axis. It
is a forested stratovolcano that rises above the remote jungles
of the western Amazon basin. A 3-km-wide caldera breached to the
E was formed by edifice collapse and is partially filled by a
young, unvegetated stratovolcano that rises about 1,300 m above
the caldera floor. Reventador has been the source of numerous
lava flows as well as explosive eruptions that were visible from
Quito in historical time. Frequent lahars in this region of
heavy rainfall have constructed a debris plain on the eastern
floor of the caldera. (GVN/GVP)
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Tungurahua from Pelileo - H.Gaudru - 1999 |
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MONTSERRAT
-
Soufriere Hills volcano - West-Indies
May 8th,
2010
Report
for the period from 5th of February 2010 to 7th of May 2010-
Activity at
the Soufrière Hills Volcano has been low this week (30th of
April to 7th of May). There have been fifteen rock fall signals,
two long period, one hybrid and four volcano tectonic
earthquakes recorded this week. A moderate pyroclastic flow was
observed in the Tar River valley at 17:01 on 3 May stopping some
1 km short of the sea. The average sulphur dioxide flux measured
for six days this week was 728 tons per day, with a daily
minimum of 147 and a maximum of 1652 tons per day. Activity at
the Soufrière Hills Volcano remained still low from 23th to 30th
of April.There have been twenty two rock fall signals, nineteen
long period, four hybrid and two volcano tectonic earthquakes
recorded this week. A small swarm of five large hybrid and
volcano tectonic earthquakes occurred on the morning of 25
April. The average sulphur dioxide flux measured for five days
this week was 307 tons per day, with a daily minimum of 112 and
a maximum of 509 tons per day. FTIR (Fourier Transform Infrared)
measurements on two days this week gave hydrochloric acid
/sulphur dioxide ratios of 0.46 and 0.42 respectively. Activity
at the Soufrière Hills Volcano remained low this week(16th-23th
of April).There have been twenty one rock fall signals, three
long period, two hybrid and two volcano tectonic earthquakes
recorded this week. Rockfalls were observed occurring on the
eastern side of the dome moving into the Tar River Valley on 20
April and on western side of the lava dome above Gages on 22
April. The average sulphur dioxide flux measured for four days
this week was 234 tons per day, with a daily minimum of 66 and a
maximum of 405 tons per day. Small lahars associated with
rainfall occurred in the Belham Valley on 17 and 18 April.
Activity at the Soufrière Hills Volcano has been low this week
from 9th to 16th of April.There have been seven rock fall
signals, two long period, one hybrid and three volcano tectonic
earthquakes recorded this week. Several rockfalls occurred on
the western side of the lava dome on 15 April and a small
pyroclastic flow occurred on the Gages fan on 16 April. These
were probably caused by the heavy rainfall this week causing
small amounts of destabilisation on the remaining parts of the
lava dome. The average sulphur dioxide flux measured for five
days this week was 400 tons per day, with a daily minimum of 242
and a maximum of 530 tons per day. Fourier Transform infrared
measurements on the 9 April gave a hydrochloric acid /sulphur
dioxide ratio of 0.45. Heavy rain this week has generated lahars
(mudflows) on several flanks of the volcano. On afternoon of 13
April large lahars occurred in the Belham valley. Many of these
lahars were hot with abundant steam and geyersing associated
with them. Two large fans were formed at the coast of Old Road
Bay as a result of these events. These were the largest lahar
events to have occurred since November 2009. Activity at the
Soufrière Hills Volcano was also low between 2th to 9 th of
April. There were nine rock fall signals, one long period, three
hybrid and three volcano tectonic earthquakes recorded. Sporadic
rockfalls are still occurring from several areas of the lava
dome. The average sulphur dioxide flux measured for three days
this week was 376 tons per day, with a daily minimum of 213 and
a maximum of 640 tons per day. Several small areas of
incandescence (glowing) visible to the naked eye have been seen
on the lava dome on a number of nights this week. These are
probably due to hotter areas of the dome being exposed by small
rockfalls. Heavy rain on the eastern side of the island on the 2
April caused lahars in the Farm River and Trants area. Activity
was also low from 12th to 19th of March.There have been forty
one rock fall signals, three long-period, seven hybrid
earthquakes recorded this week. Small spots of incandescence on
the dome were visible to the naked eye on 14 March. Occasional
small pyroclastic flows and rockfalls are still occurring mainly
from the western and southern parts of the dome, and these may
occur at any time without warning. FTIR (Fourier Transform
Infrared) measurements this week gave a hydrochloric acid
/sulphur dioxide ratio of 0.6. The sulphur dioxide flux on 17
March was 2315 tons per day. The Hazard Level is 3. There is no
access to Zone C. Activity at the Soufrière Hills Volcano was
moderate from 5th of March to 12th of March.There have been
forty seven rock fall signals, nine long-period, seven hybrid
earthquakes and two volcano tectonic events recorded this week.
A small swarm of six hybrid earthquakes occurred on 11 March.
Heavy rain on 8 and 9 March caused some degradation of the
remaining remnants of the lava dome. As a result a series of
small to moderate pyroclastic flows moved down Gages valley to
the west on 9 March. The maximum runout of these pyroclastic
flows was about 2 km. Ashfall occurred in northeastern
Montserrat as a result of these pyroclastic flows. The heavy
rainfall this week has caused vigorous steaming of the deposits
formed on 11 February that are still hot. Strong geysering was
visible at Trants near the old Bramble airport with ash and
steam fountaining occurring. In addition lahars travelled down
several drainages around the volcano, including the Belham
valley. The Hazard Level is 3. There is no access to Zone C.
PREVIOUS WEEK Activity at the Soufrière Hills Volcano was low
from 26th of February to 5th of March. There have been seven
rock fall signals, one long-period and nine hybrid earthquakes
recorded this week. During the early hours of 4 March there was
a small swarm of seven relatively large hybrid earthquakes.
Later in the morning of Thursday 4 March there were two small
pyroclastic flows in the Tar River valley, which resulted in
light ashfall in Salem and Olveston. FTIR (Fourier Transform
Infrared) gas measurements on the 1, 2 and 4 March gave
hydrochloric acid /sulphur dioxide ratios of 0.81, 0.71 and 0.98
respectively which is a slight increase on previous weeks
values. Observations of the inside of the crater at the summit
of the dome on 26 February showed that it is shallow < 100 m
deep and approximately 200 m wide. There was no newly extruded
lava visible inside the crater. There has been a strong smell of
sulphur in some areas of Montserrat at several times this week.
This is due to the wind direction causing the gas plume from the
volcano to drift across inhabited areas. The Hazard Level is 3.
There is no access to Zone C. Activity at the Soufrière Hills
Volcano has been low between 19th to 26th of February. There
have been eleven rock fall signals and six hybrid earthquakes
recorded this week. The few rockfalls that have taken place are
mainly occurring from the walls of the collapse scar formed on
the 11 February event. Night-time views of the dome show that in
several places there are small points of incandescence visible
to the naked eye. FTIR (Fourier Transform Infrared) gas
measurements on the 19 and 22 February gave a hydrochloric acid
/sulphur dioxide ratio of 0.74 and 0.7, which is consistent with
quite slow extrusion of lava. However MVO have not yet been able
to make observations into the deep crater that exists in the
summit of the dome. The Hazard Level is 3 (as of 23 February
2010). There is no access to Zone C. Activity at the Soufrière
Hills Volcano has been low during the week from 12th to 19th of
February. There have been fifty three rock fall signals, thirty
four long period events, four hybrid earthquakes and one volcano
tectonic event recorded this week. There have been sporadic
rockfalls occurring off the inner walls of the collapse scar
formed by the 11 February event. In addition rockfalls have been
generated from the dome summit region into Gages valley. On
Sunday 14 February at 14:35 there were a series of four
moderate-sized pyroclastic flows into Gingoes Ghaut to the
southwest. These pyroclastic flows generated ashfall in
inhabited areas of northwestern Montserrat. Clear views of the
dome this week have revealed that the dome collapse scar on the
northern flank of the volcano formed by the dome collapse event
on the 11 February is approximately 300 metres wide. Separate
from the collapse scar is a deep crater of a similar diameter in
the summit of the lava dome. The pyroclastic flows formed on the
11 February have extended the coastline by a maximum of 650
metres to the east. MVO staff measured temperatures of 470oC at
Trants on Monday 15 February, these deposits will retain such
high temperatures for months. It is at present unclear whether
there is any new dome growth within the crater. However FTIR
(Fourier Transform Infrared) measurements on the afternoon of
the 17 February gave a hydrochloric acid /sulphur dioxide ratio
of 0.76, which is consistent with quite slow extrusion of lava
on that day. Activity at the Soufrière Hills Volcano was
increased significantly during previous week from 5th to 12th of
february, with two vulcanian explosions and a partial dome
collapse. The two explosions occurred at 1:49 pm on Friday 5
February and 7:57 pm on Monday 8 February, lasted 7 and 6
minutes and ash plumes reached 25,000 and 15,000 ft
respectively. There was no ashfall from either explosion in
inhabited regions of Montserrat. Pyroclastic flows associated
with the explosion on 5 February reached the sea at Aymers Ghaut
and smaller pyroclastic flows (maximum run out 2 km) also
occurred in several other valleys including Tyers ghaut. The 8
February explosion generated pyroclastic flows only in the Gages
valley and these did not reach the sea. During the first part of
the week activity was concentrated on the western side of the
dome. Beginning on 9 February the focus of activity shifted from
the west more to the northern side of the lava dome, although
pyroclastic flows on the morning of 11 February travelled to the
west, northeast and north simultaneously. The dome collapse
event on 11 February lasted 55 minutes starting at 12:35 pm and
reaching a peak at 13:04, although there were several pulses.
Pyroclastic flows moved mainly to the northeast travelling
across the sea at several points on the eastern side of the
island. Pyroclastic surges moving over the sea on the eastern
side of the island were visible from Lookout village.
Significant deposition from pyroclastic flows has extended the
coastline several hundred meters at the old Bramble airport.
Pyroclastic flows also travelled northwest into Tyers Ghaut and
down the Belham valley as far a Cork Hill. The ash plume reached
50,000 ft (from pilot reports) and drifted east and then
southeast. Ashfall occurred in northeastern Montserrat, and was
reported in southwest Antigua, Guadeloupe and Dominica. A large
collapse scar has been excavated into the northeastern flank of
the dome, although the summit of the original southwestern
portion is still intact. There have been five hundred and twelve
rock fall signals, one hundred and forty one long period events,
eighty two hybrid earthquakes and four volcano tectonic events
recorded this week.
according to
MVO the largest-scale ejection of material from the volcano for
four years. MVO's Paul Coles reported that 10-15% of the lava
dome has been removed by this collapse. Montserrat. Information
:
Montserrat Volcano Observatory -
View latest NOAA satellite image of Montserrat ( every 30 mn)
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Soufriere Hills dome on December 6, 2000 (Courtesy
Caraibean Helicopter)
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MEXICO -
Popocatepetl volcano
May 8th, 2010
As of the
7th of May, CENAPRED has reported that in the last 24 hours, the
monitoring system of Popocatepetl volcano recorded 9 low
intensity exhalations, accompanied by steam and gas emissions
and small amounts emission of ash. Also some episodes of low
amplitude tremor have been redorded. The other monitored
parameters remain without important changes. At the moment of
this report CENAPRED can see the volcano with a steam and gas
emission. From high to low probability the expected activity
scenarios in the next hours, days or weeks are: moderate
exhalations, some with ash emissions; occasionally mild
incandescence during nights and sporadic low level explosions
with low probabilities of incandescent fragment at short
distance to the crater. There is a permanent monitoring of the
volcano to detect any change. The traffic light of volcanic
alert remains in YELLOW Phase 2.
Previous
important phase : as of the 23rd of August 2009, CENAPRED
reported that the strong eruption of Popocatépetl volcano,
Mexico on the 20th August had ash emission to 27,000 ft altitude
at 1645 hr (UT). Following this event, access has been
restricted to a radius of 12 km from the crater. The road
between Santiago Xalitzintla (Puebla) and San Pedro Nexapa
(Mexico State), including Paso de Cortes, was open only to
controlled traffic. Volcano Popocatépetl, 5426 m high is located
at 70 km SE of Mexico City. The glacier-clad stratovolcano
contains a steep-walled, 250-450 m deep crater. Three major
plinian eruptions, the most recent of which took place about 800
AD, have occurred from Popocatépetl since the mid Holocene,
accompanied by pyroclastic flows and voluminous lahars that
swept basins below the volcano. Frequent historical eruptions,
have occurred since precolumbian time. Information from CENAPRED
-
Live cam of Popocatepetl -
MEXICO
- Colima volcano
December 11th, 2009
As of the
10th of December, the Government of the State, reported that on
the 1st of December a white plume from the Colima volcano rose
100 m above the crater and drifted E. On December 2nd,
incandescent tephra was ejected 50 m above the crater towards
the SE. Later that day, a white plume rose 50 m and drifted SW.D
uring 2009 Colima (also known as Volcán de Fuego) has been
emitting white and grey plumes that have reached as high as 6.4
km above sea level, and there have been occasional ejections of
incandescent material. Both ground and air exclusion zones have
been imposed around Colima by state civil protection
authorities. The high level of activity has been causing some
concern in the surrounding area, with reports of a high
possibility that the volcano is preparing to erupt; the
authorities have responded by playing down reports of imminent
risks, while stressing the need for local people to remain
watchful and prepared to respond to any increase in activity. As
of the 4th of december, the Government of the State, through the
State Unit of Civil Defence-Colima reported that fresh lava
flows and ejections of incandescent material some 50 metres from
the crater were observed on 2 December. On 26 November there was
an overflight above the summit crater which reported that the
lava dome within the main crater of Colima, which has been
growing since February 2007, now blocks 80% of the crater and
has attained a height of about 45-60 metres, diameter of 270
metres and volume of 2 million cubic metres). Material has
accumulated against the western wall of the crater and against a
section of the southern wall, which could produce occasional
landslides down the western slopes of the volcano. High
temperatures were reported within the crater. The Colima
volcanic complex is the most prominent volcanic centre of the
western Mexican Volcanic Belt. It consists of two
southward-younging volcanoes, Nevado de Colima (the 4320 m high
point of the complex) on the north and the 3850-m-high
historically active Volcán de Colima at the south. Frequent
historical eruptions date back to the 16th century. Occasional
major explosive eruptions (most recently in 1913) have destroyed
the summit and left a deep, steep-sided crater that was slowly
refilled and then overtopped by lava dome growth.
Colima's web video camera -
Colima data base
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GUATEMALA - Fuego volcano
May
8th, 2010
As of the
7th of May, the National Institute Of Sismología, Volcanology,
Meteorology And Hidrologia, (INSIVUMEH) reported that with weak
fumaroles rose to low height and moved to the southwest. The
seismic station of FG3, registers 8 explosions in 24 hours,
accompanied by weak rumblings. Expelling columns of gray ash to
400 and 900 metres of height, on the crater, in a southwestern
direction. The changing winds during the night have transported
ash-gray on Antiqua, Guatemala and other populations in the
North flank, which is normal, due to the wind of the south. As
of the 30th of April, INSIVUMEH has reported that white
fumaroles rose to 150 metres of height.The volcano maintains the
same landlord eruptive, with weak and moderate explosions,
expelling gray ash to 400 and 900 metres of height, on the
crater moving the column of ash to the north, the northeast. All
the explosions have generated rumblings and sounds of degassing,
weak and moderate. This due to the wind direction is possible to
listen to the sounds of the activity in Antigua, Guatemala and
the populations in these flanks. Rains of at night yesterday
generated again lahars by the rivers gray ash and las Lajas.
Seismic
station FG3 registers 12 explosions in 24 hours. Fuego, one of
Central America's most active volcanoes, is one of three large
stratovolcanoes overlooking Guatemala's former capital, Antigua.
Frequent vigorous historical eruptions have been recorded since
1524 and have produced major ashfalls, along with occasional
pyroclastic flows and lava flows. The last major explosive
eruption from Fuego took place in 1974, producing spectacular
pyroclastic flows visible from Antigua. From (INSIVUMEH)
GUATEMALA - Santa Maria - Santiaguito
May
8th, 2010
As of the
7th of May, the National Institute Of Sismología, Volcanology,
Meteorology And Hidrologia, (INSIVUMEH) reported that iIn the
morning 2 moderate explosions have been observed, expelling gray
ash to 300 and 700 metres on the crater from the Cono Claiente.
Few avalanches in the southwest are observed. The seismic
network of STG3, registers 29 explosions in 24 hours.
As of the
30th of April,INSIVUMEH reported that white fumaroles rose to
150 metres of height. The volcan maintains the same landlord
eruptive, with weak and moderate explosions, expelling gray ash
to 400 and 900 metres of height, on the crater moving the column
of ash to the north, the northeast. All the explosions have
generated rumblings and sounds of degassing, weak and moderate.
This due to the wind direction is possible to listen to the
sounds of the activity in Antigua, Guatemala and the populations
in these flanks. Rains of at night yesterday generated again
lahars by the rivers gray ash and Las Lajas. Seismic station FG3
registers 12 explosions in 24 hours. As of the 28th of April,
INSIVUMEH reported that the Santiaguito lava dome complex at
Guatemala's Santa María volcano erupted yesterday, producing
four explosions between approximately 18:50 and 20:00 local time
and throwing an ash-laden plume up to altitudes of between 7.3
and 8.5 km. INSIVUMEH described two of the explosions as strong
and the other two as ‘moderate to strong' in intensity. Ash
plume reached between 7.3-9.1 km hight (VAAC). According to an
Insivumeh volcanologist quoted by El Periódico , people in local
communities were alarmed by small earthquakes during the
eruption, and ashfall created visibility problems on nearby
roads. Local people had noticed rumblings from the volcano
during the night of 25 April, . The districts of Quetzaltenango,
Totonicapán, San Marcos, Huehuetenango, Suchitepéquez,
Retalhuleu and Sololá have been affected by ashfall, and classes
in local schools have been suspended. Largely because of the
ashfall hazard, Guatemala's state emergencies agency, the
Coordinadora Nacional para la Reducción de Desastres (CONRED),
has raised the alert level at Santiaguito to Orange (Naranja).
The massive dacitic Santiaguito lava-dome complex has been
growing at the base of the 1902 crater since 1922. Compound dome
growth at Santa Maria has occurred episodically from four
westward-younging vents, the most recent of which is Caliente.
Dome growth has been accompanied by almost continuous minor
explosions, with periodic lava extrusion, larger explosions,
pyroclastic flows, and lahars
GUATEMALA - Pacaya volcano
May
8th, 2010
A s of the
7th of May, the National Institute Of Sismología, Volcanology,
Meteorology And Hidrologia, (INSIVUMEH) reported that the
Mackenney crater, expelling blue and white fumaroles to 100 m of
height, moving to the South. Also constants are observed weak
explosions, without pyroclastic material (volcanic). Continuous
without active lava flows.
As of the
30th of April, INSIVUMEH reported that the white fumarole crater
rose to 200 metres of height, moving to the north. Also
constants are observed gas exhalations, with weak and moderate
sounds generated by the degassing. Seismic station PCG registers
480 explosions in 24 hours. As of the 21st of April, INSIVUMEH
reported that due to constant pluvial precipitations in the
volcanic zone of Pacaya, they were generating moderate lahars in
the rivers Santa to them Teresa, Taníluya and Ceniza, both first
affluents of the Pantaleón river. Today in the morning 6
explosions, 1 weak and 5 moderate ones have been observed
expelling columns of gray ash 500 and 700 metres of height. The
column moves to the southeast to 10 kilometres approximately.
Constant avalanches of blocks by flanks of the volcano have been
observed. All the explosions have generated weak degassing
sounds and rumblings.
During the
past several decades, activity at Pacaya has consisted of
frequent strombolian eruptions with intermittent lava flow
extrusion that has partially filled in the caldera moat and
armored the flanks of MacKenney cone, punctuated by occasional
larger explosive eruptions that partially destroy the summit of
the cone.
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COSTA
RICA - Arenal volcano
March
30th, 2010
OVSICORI-UNA reported that during March activity originating
from Arenal's Crater C consisted of gas emissions, sporadic
Strombolian eruptions, and occasional avalanches. A lava flow
that began in mid-January remained active on the S flank. Acid
rain and small amounts of ejected pyroclastic material
affected the NE, E, and SE flanks. Avalanches from the crater
and from lava-flow fronts traveled down the SW, S, and SE
flanks, occasionally igniting vegetation. Crater D produced only
fumarolic activity.
OVSICORI-UNA reported that during February activity originating
from Arenal's Crater C consisted of gas emissions, sporadic
Strombolian eruptions, and occasional avalanches. A lava flow
traveled down the SW
flank. Acid rain and small amounts of ejected pyroclastic
material affected the NE and SE flanks. Avalanches from the
crater and from lava-flow fronts traveled down the SW, S, and SE
flanks, occasionally igniting vegetation. Crater D produced only
fumarolic activity.As of the 19th of November, OVSICORI-UNA
reported that during October activity originating from Arenal's
Crater C consisted of gas emissions, sporadic Strombolian
eruptions, and occasional avalanches that traveled down the W
and SW flanks. Acid rain and small amounts of ejected
pyroclastic material affected the NE and SE flanks. Avalanches
from lava-flow fronts traveled down the SW flanks. Crater D
produced only fumarolic activity.
As of the
15th of October, the Global Volcanism Network (GVN) reported
that OVSICORI-UNA reported that during September activity
originating from Arenal's Crater C consisted of gas emissions,
sporadic Strombolian eruptions, and occasional avalanches that
traveled down the W flank. Acid rain and small amounts of
ejected pyroclastic material affected the NE and SE flanks.
Avalanches from lava-flow fronts traveled down the SW flanks.
Crater D produced only fumarolic activity.
As of the
16th of July, OVSICORI-UNA reported that on July 7th and 8th,
2009 a probable lava front collapse took place to the south side
of Arenal volcano, Costa Rica. For several months, prior to this
event, minor explosive activity and rolling blocks were low.
Most of the fragmented blocks were associated to the emplacement
of summit material from activity triggered during the mid months
of 2008. A round noon on Tuesday (10th) and 2200 hrs on
Wednesday (the 11th), collapses started from the summit
transporting fresh and pre-emplaced blocky lava down the flank,
leaving a wide channel (80-100m wide, 20-30m deep, 800m long)
and some other topographical changes. Witnesses reports and
photographic evidence shows dust clouds developing from the
pyroclastic flows as they descended the flanks and moving N and
NW up to some 5 km. from the source. Although this activity
impacted part of the forest in that flank no tourist or park
rangers were directly affected. As of the 18th of June, OVSICORI
reported that three strong eruptions on 16 June resulted in
pyroclastic flows. The National Park was evacuated as a
precaution, but reopened the next day. Increased degassing the
previous week had prompted an elevation of the hazard status to
Level 3 (on a scale of 1-4). OVSICORI-UNA reported that during
April activity originating from Arenal's Crater C consisted of
gas emissions, sporadic Strombolian eruptions, and occasional
avalanches that traveled down the SW, S, and N flanks. Acid rain
and small amounts of ejected pyroclastic material affected the
NE and SE flanks. Small avalanches of volcanic material traveled
down several ravines. Crater D showed only fumarolic activity.
Crater D showed only fumarolic activity. OVSICORI-UNA reported
that during January, activity originating from Arenal's Crater C
consisted of gas emissions, sporadic Strombolian eruptions, and
occasional avalanches from lava-flow fronts that traveled down
the SW flanks. Volcanic activity was at relatively low levels
and few eruptions occurred. Acid rain and small amounts of
ejected pyroclastic material affected the NE and SE flanks.
Eruptions produced ash plumes that rose about 2.2 km (7,100 ft)
a.s.l. Small avalanches of volcanic material traveled down
several ravines. Crater D showed only fumarolic activity As of
the 2nd of October, the Observatorio Vulcanológico y Sismológico
de Costa Rica reported that changes in morphology and the health
of vegetation at Arenal were documented during approximately
14-20 September. Fine ashfall produced at the summit by an
active lava flow impacted and burned vegetation along the upper
and lower E and NE flanks. The impact on the vegetation was more
severe near the summit. By mid September, additional material
moving down the SW flank had filled the 6 June collapse scar and
built an 800-m-high levee. Occasional incandescent blocks roll
down the top of the levee. Material accumulated on both sides of
the levee and at the distal end, creating a 200-m-wide fan. A
mass of material also accumulated at the SW edge of the summit,
causing blocks to occasionally roll down the N flank. As of the
1st of August, the Observatorio Vulcanológico y Sismológico de
Costa Rica reported that the growth of Arenal has been
characterised by periodic major explosive eruptions at
several-hundred-year intervals and periods of lava effusion that
armor the cone. It continues to erupted, on and off, from
time-to-time.
As of Friday
6th of June 2008 at 9:15am (15:15GMT) OVSICORI reported that a
hot avalanche rolled down the SW slopes of Arenal volcano, Costa
Rica. An unestimated amount of blocky, andesitic lava was
accumulating, on the summit, since March 2007 due to the
extrusion of a lava flow. Even though fragments of such lava
flow fell intermittently over these 14 months, it was until now
that a mayor avalanche took place. Two minor ones were reported
in recent months. The present collapse provoked a scar of some
800m long from the summit to the bottom. Lose, dry, incandescent
material was canalized down the slope conforming a wide chaotic
fan, at aprox 900m asl. Material rolling down pulverized and
generated a tall plume of gases and dust that provoked panic in
tourists and park rangers located some 2 kms. away, on the W
side. Immediately the park was closed for the day and the
tourists rapidly evacuated. No one was hurt. Dust and fine ashes
deposited in a small area W and NW of the active flank. Rain
rapidly diluted the fine film that was deposited on
vegetation.Previously OVSICORI-UNA confirmed that a pyroclastic
flow from Arenal traveled W on 18 september 2007. The event was
recorded by a local seismic station. Based on field
observations, a scientist from Instituto Costarricense de
Electricidad (ICE) reported that multiple pyroclastic flows
traveled S an approximate distance of 1 km on 18 September.
Explosions occurred that occasionally produced ash. Small
avalanches were noted and one larger avalanche on the S flank
was incandescent. Avalanche activity continued on 19 September.
Conical Volcán Arenal is the youngest stratovolcano in Costa
Rica and one of its most active. The 1657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which
has been enlarged by a hydroelectric project. Arenal lies along
a volcanic chain that has migrated to the NW from the
late-Pleistocene Los Perdidos lava domes through the
Pleistocene-to-Holocene Chato volcano, which contains a
500-m-wide, lake-filled summit crater. The earliest known
eruptions of Arenal took place about 7000 years ago, and it was
active concurrently with Cerro Chato until the activity of Chato
ended about 3500 years ago. Growth of Arenal has been
characterised by periodic major explosive eruptions at
several-hundred-year intervals and periods of lava effusion that
armor the cone. Arenal's most recent eruptive period began with
a major explosive eruption in 1968. Continuous explosive
activity accompanied by slow lava effusion and the occasional
emission of pyroclastic flows has occurred since then from vents
at the summit and on the upper western flank.
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COSTA
RICA- Poas Volcano
February 23rd, 2010
As of the
23rd of February, OVSICORI-UNA reported that a new phreatic
explosion occured on 23rd of February at 11: 33 AM (local time).
Slight ashfalls occured on Southwest and Southeast flanks of the
volcano. No precursor signal was recorded. As of the 28th of
December, the Observatorio Vulcanológico y Sismológico de Costa
Rica (OVSICORI-UNA) reported that on the 25th of December a
phreatic eruption from Laguna Caliente, a summit lake of Poás,
was seen by visitors standing at a viewpoint to the S of the
crater. Lake water mixed with sediment and blocks was ejected
550-600 m above Laguna Caliente and fell in the vicinity of the
lake, within the crater. The amount of steam emitted from
lava-dome fumaroles, at the S edge of the lake, increased
subsequent to the eruption.
According to
a local paper, a phreatic explosion occured on Friday morning,
18 September. This explosive event projected water and sediment
to a height of about 300 meter above the surface of the crater
lake. It is the northern of the volcano's two summmit crater
lakes named Lago Caliente, which is the site of frequent
phreatic eruptions; the most recent, a smaller event, was in
January.The paper also mentions that scientists visiting the
summit of the voclano have found burning sulphur on the north
wall of the crater lake, the first time this phenomenon has been
seen since 1994. Recent high temperatures and low rainfall have
reduced the water volume in the highly acidic lake, and
degassing from the crater has intensified with the gas plume of
bright yellow' in certain areas and reaching 400 metres in
height when measured on 16 September. Previous information : a s
of the 14th of January, OVSICORI reported that on Monday 12th of
January Poas Volcano produced a shy phreatic explosion, confined
to the center of the lake. More intriguing is the fact that such
activity occurred after the fatal Cinchona earthquake felt on
Thursday, January 08, 2009 resulting of a local faulting event.
Epicenter is located some 6 km E of the volcano probably
disturbing the balance of an already fractured and shallow
hydrothermal system.. As of the 8th of January at 1:21 PM a
violent earthquakes (mag. 6.1- 6km depth) occured at about 10km
East of the Poas volcano. Ten people were killed by a landslide
at La Paz waterfall. Three people were killed by landslides in
the Fraijanes-Dulce Nombre area and one person died of a heart
attack in the San Jose area. Many people were injured, many
buildings were damaged and landslides blocked roads in the area.
Electricity was knocked out in parts of San Jose. Felt (VI) at
Asuncion, Grecia and San Pablo; (V) at Alajuela, Colon,
Curridabat, Desamparados, Escazu, Guadalupe, Heredia, Mercedes,
Quesada, Sabanilla, San Antonio, San Francisco, San Isidro, San
Jose, San Juan, San Pedro, San Rafael, Santa Ana and Santo
Domingo; (IV) at Atenas, Cartago, San Ramon, and Tres Rios;
(III) at Jacao. Felt throughout Costa Rica and in southern and
central Nicaragua.
Following
this event, an increasing of the fumarolian activity in the
crater was observed by OVSICORI scientists; probably due to the
destabilization of the geothermal system. As of the 25th of
January, the Observatorio Vulcanológico y Sismológico de Costa
Rica (OVSICORI-UNA) has reported that a visit on January 18th,
2008 confirmed a report that a small phreatic eruption occurred
within the perimeter of the hot-acidic lake of Poás volcano,
around 0900hrs on Sunday, January 13th, 2008. The first notice
was given by a park ranger and described as cipresoidal shape
with ejection of water and sediments out of the center of the
lake. It did reach some 200m high and subsequently collapsed to
change rapidly the lake's colour from a dark green to an intense
white. This event was also witnessed by a group of tourists who
were temporarily evacuated but were always safe at some 1200m,
observing the volcano from the main viewpoint. Field inspection
revealed also that the explosion produced a wave of 1.5m all
around the lake leaving a mark along its rim. Only to the south,
next to the north dome's terrace, squirts of sediments were
found reaching distances of some 8m from the shore. Such
sediments were washed off, probably by the returning wave and
reached a thickness no greater than 10cm. Such pockets of
sediments contain a large quantity of shining crystals and other
pre-existent minor debris from the bottom of the lake. No blocks
were expelled out of the lake. The person that made the first
report emphasised the calm conditions of the lake and dome
before the eruption. Also, a small landslide (8x20m) was
documented on the north face of the dome. It did leave a chaotic
deposit of heavily altered angular blocks in a gray matrix
altered by hydrothermalism. A slurry of yellowish materials
reached the edge of the lake. Due to rapid outlet of gases in
concentric convection cells from the centre of the lake, the
lake changed its colour progressively in a matter of some 3
hours during the visit of OVSICORI´s staff. Even more, rapid
degassing from the surface of the lake impedes the sight to the
other side, due to thick columns of toxic gases. Lake
temperature dropped to 45ºC and water level raised 1.5m compared
to the last estimate at the end of November 2007. Nonetheless
rapid evaporation promotes rapid reduction of such level. Poás,
one of the most active volcanoes of Costa Rica, contains three
craters along a N-S line. The frequently visited multi-hued
summit crater lakes of the basaltic-to-dacitic volcano, which is
one of Costa Rica's most prominent natural landmarks, are easily
accessible by vehicle from the nearby capital city of San José.
A N-S-trending fissure cutting the 2,708-m-high complex
stratovolcano extends to the lower northern flank, where it has
produced the Congo stratovolcano and several lake-filled maars.
The southernmost of the two summit crater lakes, Botos, is cold
and clear and last erupted about 7,500 years ago. The more
prominent geothermally heated northern lake, Laguna Caliente, is
one of the world's most acidic natural lakes, with a pH of near
zero.
COSTA
RICA - Turrialba volcano
March
10th, 2010
OVSICORI-UNA reported that scientists visited Turrialba at night
on 7 March. A gas plume, commonly seen drifting with prevailing
winds, was seen that night rising 1.5 km above the crater and
drifting NW. Noises from the crater were described as sounding
like a jet engine and rumblings. A vent, formed in January,
emitted gas at temperatures between 300 and 320 degrees Celsius.
Small blocks 3-12 cm in diameter and different colors dominated
the surface around the vent. Lithics ejected 30-50 m away from
the vent measured 170 degrees Celsius. Incandescence seen at
night originated from the vent which ejected reddish-colored
tephra. As of the 3rd of february, OVSICORI reported that
Turrialba, which erupted on a small scale at the beginning of
January, has returned to a state of passive degassing similar to
that which pertained before the eruption.However, volcanologists
have warned that although activity has declined low intensity
earthquakes continue, the volcano remains active and people
should not be complacent. The comision Nacionale de emergency
(CNE) has revised the alert level currently applied to the area
surrounding the volcano, with Yellow Alert now applying to a 2
km radius zone around the volcano and Green Alert to areas
beyond that limit. Previously, on 20 January 2010 an overflight
of Turrialba took place which reported a revitalization of the
column of gas and steam with suspended particles. A photography
of the activity was taken during this overflight. A sustained
emission was reported on that day, with a thick, dark plume from
the summit moving WNW, the strong wind preventing the plume from
rising much above the altitude of the volcano. Some light
ashfall was reported in areas near the volcano. Although the
transport and distribution of volcanic particles (old ash) is a
new occurrence for this eruptive period of Turrialba volcano,
notes the report, the minimal quantity carried this morning
could be the first of much more in the near future as material
eroded from the internal walls of the active conduit is carried
up into the plume. After the first round of phreatic eruptions
during 5-6 January from Turrialba volcano OVSICORI published the
following field report : "A visit to the field on jan 6th shed
light about what happened between the night of Monday 5th and
early hours of Wednesday 6th. At least two vents (between 20 and
30m wide) opened along the inner walls of W crater, to eject an
unestimated volume of preexistent fine particles. A narrow plume
(8x40 km) of sediments moved SW up to 40 kms reaching a small
portion of the populated Central Valley where most Costarricans
live. Thickness of deposits vary from few mm (near the summit)
to a fine sheet after some 15 km away from the volcano.
Granulometry of particles vary from 1mm, in the proximal area to
micras, in the distal areas. No juvenile material was found in
the described deposits, on the contrary its color, shape and
general aspect coincide with the openings in the upper summit.
Strong degassing accompanied of fractionated material is
intermittently expelled from the new vents as we write this
report. Although the tremor signal decreased, compared to two
preceding days, energy is enough to produce columns of several
hundreds of meters above the summit. Fortunately nobody was hurt
during the initial explosions and most of settlers, 3 kms around
the volcano, got evacuated. Damage to crops, machinery and
infrastructure has not been assessed although it is believed
that it may increase if emissions persist." A low-amplitude
tremor continued until 16:58 on 8 January; since that time the
tremor has ended and the volcano has returned to the same LP
type earthquakes that were recorded before 4 January, and now
activity at the volcano has returned to the levels of before the
phreatic eruption. Previously, as of the 5th of January OVSICORI
reported that at 14:48 local time an inhabitant of the La
Central area located to the south-west of Turrialba volcano
reported hearing a strong eruption of Turrialba, much later
people living near the volcano reported ashfall. Also, officials
of the Parque Nacional Volcán Irazú reported the presence of ash
in vehicles parked in the car park inside the national park.
Additionally, residents of Turrialba, Tres Ríos and owners of
properties on the slopes of Turrialba volcano reported ashfall.
From mid-December 2009 until 4 January 2010, LP-type earthquakes
(low frequency) had been predominantly registered, with a
significant decrease of volcanic tremor. On 4 January 2010 there
was a significant increase in volcanic tremor, both in duration
of registration and in the amplitude of the signal. Coinciding
with the increase in the recording of tremor there was a
significant decrease in LP-type earthquakes. In the early hours
of Wednesday 6 January an OVSICORI-UNA team will go to the area
to make observations and collect data and information to carry
out relevant studies. A green (preventative) alert was issued by
the authorities for the area around Turrialba, and about 20
people were evacued from the volcano's slopes. Previously, a s
of the 2nd of September, according to OVSICORI scientists, the
volcano was showing again an increase in degazing activity.
Turrialba, the easternmost of Costa Rica's Holocene volcanoes,
is a large vegetated basaltic-to-dacitic stratovolcano located
across a broad saddle NE of Irazú volcano overlooking the city
of Cartago. The massive 3340-m-high Turrialba is exceeded in
height only by Irazú, covers an area of 500 sq km, and is one of
Costa Rica's most voluminous volcanoes. Three well-defined
craters occur at the upper SW end of a broad 800 x 2200 m wide
summit depression that is breached to the NE. Most activity at
Turrialba originated from the summit vent complex, but two
pyroclastic cones are located on the SW flank. Five major
explosive eruptions have occurred at Turrialba during the past
3500 years. Turrialba has been quiescent since a series of
explosive eruptions during the 19th century that were sometimes
accompanied by pyroclastic flows. Fumarolic activity continues
at the central and SW summit craters.INFORMATION from OVSICORI -
SVE Volcanic fieldtrip on group request.
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NICARAGUA - Concepcion volcano
March 26th, 2010
As of the
26th of March, INETER reported that on 22 March that degassing
and seismic activity had fallen to low levels in comparison with
the preceding days. On 24 March INETER confirmed a considerable
reduction in activity but reported continuing anomalous levels
of seismicity. The current situation is that activity remains
low, but the volcano continues to be carefully monitored. As of
the 19th of March, INETER, informed that the emanations of gases
and ashes in the volcano Conception fell today. In the morning 2
explosions were entered, first of them it reached an
approximated height of 500 metres over the crater and a second
height that did not surpass the 100 metres on the crater. In the
evening the volcano entered a relative calm. Seismic it is
observed that it continues the occurrence of small earthquakes,
which have not been located due to the very low magnitude.
INETER, maintains the monitoring of the volcano the 24 hours of
the day and it will generally be continued informing to the
population on changes. According to the Washington VAAC, INETER
reported an eruption from Concepción on 12 March. A
rapidly-dissipating ash cloud was seen on satellite imagery
almost 60 km E of the summit. As of the 10th of March, Based on
information from INETER and analyses of satellite imagery, the
Washington VAAC reported that on 8 March an ash plume from
Concepción rose to an estimated altitude of 2.1 km a.s.l. The
plume was last seen in satellite imagery later that day 227 km
W. As of the 11th of December 2009, INETER reported that
Concepcion volcano erupted on Friday. Summit explosion spewing
gas and smoke almost 500 feet (150 metres) into the air and
ashfalls occured on three nearby villages, but there were no
immediate reports of damage. Volcán Concepción is one of
Nicaragua's highest and most active volcanoes. The symmetrical
basaltic-to-dacitic stratovolcano forms the NW half of the
dumbbell-shaped island of Ometepe in Lake Nicaragua and is
connected to neighboring Madera volcano by a narrow isthmus. A
steep-walled summit crater is 250 m deep and has a higher
western rim. N-S-trending fractures on the flanks of the volcano
have produced chains of spatter cones, cinder cones, lava domes,
and maars located on the NW, NE, SE, and southern sides
extending in some cases down to Lake Nicaragua. Concepción was
constructed above a basement of lake sediments, and the modern
cone grew above a largely buried caldera, a small remnant of
which forms a break in slope about halfway up the north flank.
Frequent explosive eruptions during the past half century have
increased the height of the summit significantly above that
shown on current topographic maps and have kept the upper part
of the volcano unvegetated.
NICARAGUA - San Cristobal volcano
September 7th, 2009
A s of the
10th of December, the Instituto Nicaragüense de Estudios
Territoriales (INETER) informs that based on analyses of
satellite imagery, the Washington VAAC reported that on 6
December a gas-and-steam plume from San Cristóbal, possibly
containing ash, drifted SW. The VAAC also noted smoke from local
fires.
As of the 6th of September INETER reported that eight explosions
occured on Sunday 6th of September 2009 during afternoon at the
San Cristobal volcano spewing gases and ash to about 200 m above
the summit crater and some ashfalls on nearby towns. A statement
from the Instituto Nicaragüense de Estudios Territoriales
reports that at 1:50 this afternoon San Cristóbal volcano
produced explosions of gas and ashes. The first explosion was
detected by the seismic station located on the south-west slope
of this volcano, and generated a column that reached an
approximate altitude of 200 metres, remaining static because of
the absence of wind. There then were four explosions of lesser
intensity. According to reports from Defensa Civil personnel in
the communities around the volcano, the activity continued until
approximately 2:40 in the afternoon. There are no reports of
injuries or damage. Sunday's blasts prompted officials to issue
an alert for 25 districts near the volcano. The San Cristóbal
volcanic complex, consisting of five principal volcanic
edifices, forms the NW end of the Marrabios Range. The
symmetrical 1745-m-high youngest cone, named San Cristóbal (also
known as El Viejo), is Nicaragua's highest volcano and is capped
by a 500 x 600 m wide crater. El Chonco, with several flank lava
domes, is located 4 km to the west of San Cristóbal; it and the
eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of
Pleistocene age. Volcán Casita, containing an elongated summit
crater, lies immediately east of San Cristóbal and was the site
of a catastrophic landslide and lahar in 1998. The
Plio-Pleistocene La Pelona caldera is located at the eastern end
of the San Cristóbal complex. Historical eruptions from San
Cristóbal, consisting of small-to-moderate explosive activity,
have been reported since the 16th century. Some other
16th-century eruptions attributed to Casita volcano are
uncertain and may pertain to other Marrabios Range volcanoes.San
Cristobal's last such activity occurred three years ago. GVN/GVP
- NOTE :
a
SVE fieldtrip in Nicaragua is planned for November 2010
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COLOMBIA - Galeras volcano
May
8th, 2010
As of the
6th of May, the Observatory Vulcanológico and Sismológico de
Pasto reported that low levels in the seismicity stay. The
occurrence of a cluster of earthquakes that appeared between the
2nd and 3rd of May, with the registry of near 90 events of small
power level is emphasised. The earthquakes related to fracturing
processes were located in different zones in the volcanic
complex, the majority with depths smaller to 3 km with respect
to the top and with local magnitudes inferiors to 1 on the
Richter scale. During the week Sulphur Dioxide (SO 2 emissions
were registered with values considered as low for Galeras, 215
min to Tonnes/day. With the support of the Colombian Air Force,
the 30th of April was realised in a fly over to Galeras volcano,
being observed permanent gas emission of clear colour from
different sectors from the active cone. The taken thermal images
in this day, showed the presence of several sectors with thermal
anomalies, mainly inside the main crater, with maximum values
between 87 and 97 °C. The climatic conditions allowed the
observation from Pasto, of small columns of emission of white
colouration, on the 29th and 30th of April and the 4th of May,
with peak altitudes of 200 m on the top. As of the 28th of
April, the Observatory Vulcanológico and Sismológico de Pasto
reported that the registered seismicity continues within levels
considered as low, predominating the events that involve as much
fracture of cortical material as movement of the flowed
components of the system. The earthquakes related to fracturing
were located without showing a source in particular, being
located of dispersed way with depths of up to 7 km with respect
to the top and with local magnitudes that did not surpass the
1.4 degrees on the Richter scale. During the week Sulphur
Dioxide (SO2 emissions were not registered instrumentally As of
the 21st of April, the volcano continued the seismicity levels
considered as low, with the predominance of events related to
the flowed components of the volcanic system. The events
associated with fracturing processes were located of dispersed
way in the volcanic complex and nearest the active crater they
were located to depths smaller to 2 km with respect to the top.
The registered earthquakes of fracture in the afternoon of
today, were located to 5 km to the West-Northwest of Galeras
approximately, to 7 km of depth and with magnitudes smaller than
1.4 on the Richter scale. During the week Sulphur Dioxide (SO 2
emissions were not registered instrumentally. On the 16th of
April, the climatic conditions favoured the observation of small
columns of emission of white colouration, that reached peak
altitudes of 250 m on the top, with preferential dispersion
towards the north of the volcanic complex by action of winds.
As of the
15th of April, the Observatory Vulcanológico and Sismológico de
Pasto reported that the levels considered as low stay in the
seismicity, with the predominance in this period, of events
related to the flowed components of the volcanic system. During
the week Sulphur Dioxide SO 2 emissions were registered again in
levels considered as low. On the 7th, 10th and 12th of April,
the climatic conditions as much favoured the observation of
small columns of emission of white colouration, that reached
peak altitudes of 400 m on the top, with dispersion towards the
north as to the south of the volcanic complex.
As of the 8th
of April, the Observatory Vulcanológico and Sismológico de Pasto
reported that seismicity levels within are considered as low,
they are continued presenting/displaying some fluctuations in
the occurrence and energy of the earthquakes. The events related
to processes of fracturing of cortical material, continue
happening of dispersed way distances of up to 14 km of the main
crater. Within this seismicity the registered event is
emphasised the 4th of April, with magnitude 1.9, that was
located to about 2 km to the southwest of the active cone and to
a depth of 2 km with respect to the top. During the week Sulphur
Dioxide emissions were registered in considered levels low (SO 2
). On the 2nd and 6th of April, the climatic conditions favoured
the observation of small columns of emission, that reached peak
altitudes of 200 m on the top, with preferential dispersion
towards the north-western flank of the volcanic complex.
As of the 1st
of April, the Observatory Vulcanológico and Sismológico de Pasto
reported that although a slight increase in the seismicity
appeared, as much continue the low levels in occurrence as in
the released energy, similar to the reported ones in the
previous weeks. The earthquakes related to processes of
fracturing of cortical material, happened of dispersed way to
distances of up to 11 km of the active cone, with local
magnitudes smaller to 1.1 on the Richter scale. The events near
the crater are located in more superficial levels, with depths
smaller to 3 km with respect to the top. During the week Sulphur
Dioxide (SO 2 )emissions were not registered. As of the 24th of
March, the Observatory Vulcanológico and Sismológico de Pasto
reported that the volcano continues low levels of seismicity,
similar to the reported ones for the previous weeks. The
earthquakes related to processes of fracturing of cortical
material, happened of a dispersing way in the volcanic complex,
with smaller depths of 7.5 km and magnitudes principles of 0.7
on the Richter scale. During the week it was continued measuring
low emissions of SO 2 flow (Sulphur Dioxide), with values of 165
and 115 tonnes/day registered on the 16th and 18th respectively
of March of 2010. On the 20th of March, personnel of the OVSP in
work of field by the zone of the high part of La Quebradathe
Maragato (Municipality of Nariño), reported afternoon in the
hours of scents to sulphured gases. In a fly over carried out
the 22nd of March, with support of the Colombian Air Force,
verified gas discharge of white colour, by different sectors
from the active cone and generally in low amount. In the morning
of today, they were seen from the city of Pasto, gas pulses of
white colour, with smaller heights of 200 m on the top.
As of the
17th of March, the Observatory Vulcanológico and Sismológico de
Pasto reported that low levels of seismicity, similars to
reported for the previous weeks and the absence of earthquakes
associated with gas discharge stay. The registry of a
volcano-tectonic event on March 12th at 2128 hrs., located
approximately to 6 km to the ENE of the active cone in environs
of the municipality is emphasized of Pasto, with a depth near 8
km and local magnitude of 2 degrees in the Richter scale. This
earthquake reported sense in some districts of the north of the
city. During the week low values of SO 2 (Sulphur Dioxide) flow
were moderate, being the maximum of 208 tonnes/day, which was
obtained on March 11th in a passage between Pasto and Nariño. On
March 10th, personnel of the OVSP realised a visit from
recognition to the Camino Real, on the flank he orients and
northwest of the volcanic complex, and from the sector of La
quebrada Maragato in future, they reported to feel strong scents
to sulphured gases. Galeras, a stratovolcano with a large
breached caldera located immediately west of the city of Pasto,
is one of Colombia's most frequently active volcanoes.
Webcam image
COLOMBIA - Nevado del Huila volcano
May
8th, 2010
As of the
6th of May, the the Observatory Vulcanológico and Sismológico de
Popayan (INGEOMINAS) reports that in the present week 1958
seismic events was registered. Of them, 51 was related to
fracturing of rock and 1907 with the dynamics of flowed within
the volcanic conduits; of these last ones, 1882 correspond to
events of long period, five (5) events hybrid type that obey to
conjugated phenomena of fracturing of rock and dynamics of fluid
and 20 pulses of tremor of low magnitude. Of the registered
seismic activity during the week, the event is emphasised of
type VT Friday at 0417 hrs, which had a magnitude of 2.6 on the
Richter scale, it was located to the southwest of the volcano to
a depth of 7.5 km and was reported as sensed by the settlers of
the Plan of Caloto, Tálaga and Tóez. In satelite images obtained
through sensor OMI and published by the Agency the International
NOAA (National Oceanic and Atmospheric Administration), on the
28th, 29th and 30th of April were observed SO 2 emissions the
atmosphere. During the last week the volcano daily continued
presenting/displaying increases in the number of registered
events, being observed a clear dominion of the seismicity
associated with the dynamics of flowed within the internal
conduits. This phenomenon does not imply a evolution to states
of greater excitation than they motivate a change of level of
activity of the volcano, and could be related to the process of
extrusion of magmatic material, that appears in the high part of
the volcano since the end of 2009. As of the 28th of April, the
the Observatory Vulcanológico and Sismológico de Popayan
(INGEOMINAS) reported that in the present week 1443 seismic
events was registered. Of them, 42 were related to fracturing of
rock and 1401 with the dynamics of flowed within the volcanic
conduits; of these last ones, 1381 corresponds to events of long
period, an earthquake hybrid type which obeys to conjugated
phenomena of fracturing of fluid rock and dynamics of and 19
with pulses of tremor of low magnitude, some of these last ones
could be associate with pulsating emissions of gases and ashes
towards surface, that until the moment have not been confirmed.
In today a movable measurement of SO 2 was realised on the
Pan-American route that communicates the populations of
Villarrica and Mondomo (the Cauca); the calculated flow was of
2348 tonnes/day in a column that dispersed towards the West of
the volcano. This, along with the registry of the satelite
images published by international agency NOAA (National Oceanic
and Atmospheric Administration), for the 21st and 27th of April,
demonstrates that the emission of SO 2 to the atmosphere stays.
Of the data obtained during the week, one concludes that they
continue appearing manifestations associated with the dynamics
of fluids, without it implies a evolution to states of greater
excitation than they motivate a change of level of activity of
the volcano.
Nevado del
Huila, the highest active volcano in Colombia, is an elongated
N-S-trending volcanic chain mantled by a glacier icecap. The
andesitic-dacitic volcano (5635 m) was constructed within a
10-km-wide caldera. Only a single 16th-century explosive
eruption is recorded in historical time from this little known
volcano.
Webcam
COLOMBIA - Cerro Machin volcano
December 7th, 2009
Ingeominas
reported as of the 7th of December, that a seismic swarm which
occured on Saturday has provoked the Colombian state geological
service to raise the alert level to Yellow (III), characterized
as ‘ "changes in the behaviour of the volcanic activity'.
According to a local newspaper, 54 minor earthquakes took place
over the weekend. The largest of these was at 1.3 on the Richter
scale. The seismic swarm took place from 5:00 p.m. on Saturday,
and although small, is the largest to have occurred in 2009,
after strong activity in 2008'. No bulletin on developments at
Machín has yet been published on the Manizales Volcano
observtory website. Any reactivation of Machín voclano could
pose a substancial threat to this populous area of Colombia,
including the large city of Ibagué (approximate population
500,000). The small Cerro Machín stratovolcano lies at the
southern end of the Ruiz-Tolima massif about 20 km WNW of the
city of Ibagué. A 3-km-wide caldera is breached to the south and
contains three forested dacitic lava domes. Voluminous
pyroclastic flows traveled up to 40 km from the volcano during
eruptions in the mid-to-late Holocene perhaps associated with
formation of the caldera. Late-Holocene eruptions produced
dacitic block-and-ash flows that traveled through the breach in
the caldera rim to the west and south. The latest known eruption
of Volcán Cerro Machín took place about 800 years ago.
************************************************************************************************************************
PERU -
Ubinas volcano
June
18th, 2009
Based on
SIGMET notices and analysis of satellite imagery, the Buenos
Aires VAAC reported that during 11 and 13-15 June eruptions from
Ubinas produced ash plumes that rose to altitudes of 5.5-7.9 km
(18,000-26,000 ft) a.s.l. Plumes drifted NE, E, and SE. Ash was
not identified on satellite imagery on 13 June Based on analysis
of satellite imagery, the Buenos Aires VAAC reported that on 5
June plumes from Ubinas rose to altitudes of 6.1-6.7 km
(20,000-22,000 ft) a.s.l. and drifted W and S. A pilot reported
that
an ash plume rose to an altitude of 7.9 km (26,000 ft) a.s.l.
and drifted SW. On 6 and 9 June, plumes seen on satellite
imagery rose to altitudes of 6.1-7.6 km (20,000-25,000 ft)
a.s.l. and drifted S and NE, respectively. On 29 and 31 May
eruptions from Ubinas produced ash plumes that rose to altitudes
of 5.5-6.7 km (18,000-22,000 ft) a.s.l. and drifted NE and SW.
Ash was not detected on satellite imagery on 31 May. INGEMMET
reported on 1 June a bluish gas plume with some ash content. On
2 June, an explosion was detected and gas-and-ash plumes that
rose 0.9-1.5 km drifted E. Ubinas in the northernmost of three
young volcanoes located along a regional structural lineament
about 50 km behind the main volcanic front of Peru. The upper
slopes of the stratovolcano, composed primarily of Pleistocene
andesitic lava flows, steepen to nearly 45 degrees. The
steep-walled, 150-m-deep summit caldera contains an ash cone
with a 500-m-wide funnel-shaped vent that is 200 m deep.
Debris-avalanche deposits from the collapse of the SE flank of
Ubinas extend 10 km from the volcano. Holocene lava flows are
visible on the volcano's flanks, but historical activity,
documented since the 16th century, has consisted of intermittent
minor explosive eruptions.
*******************************************************************************************************************
CHILE - Chaiten volcano
March 20th, 2010
As of the
20th of March, SERNAGEOMIN reported that on the 17th of March
during the previous few weeks, growth of Chaitén's lava-dome
complex was concentrated in the W part. Gas-and-ash plumes, seen
through the video camera located on the rim of the caldera, rose
at most 1 km from the central area of the domes. Seismic
activity persisted at a low level. The Alert Level remained at
Red. Based on web camera views and analyses of satellite
imagery, the Buenos Aires VAAC reported that a diffuse ash plume
from Chaitén's lava-dome complex, likely mixed with steam and
gas, drifted NE on 15 March. As of the 18th of February,
SERNAGEOMIN reported that on 11 February, ODVAS-SERNAGEOMIN
reported that a camera, installed 800 m from the centre of
Chaitén's lava-dome complex in late January, showed
incandescence and gas emissions on the 28th of January.
Seismicity had also increased during 21 January-3 February. The
Alert Level remained at Red. Based on web camera views and
analyses of satellite imagery, the Buenos Aires VAAC reported
that a steam-and-gas plume drifted 25 km NW on the 11th of
February at an altitude of 2.4 km (8,000 ft) a.s.l.
During 5-19
January the lava-dome complex continued to grow, although
possibly at rates lower than during previous weeks. The
magnitude and number of hybrid earthquakes decreased. The Alert
Level remained at Red. As of the 3rd of December, SERNAGEOMIN
reported that based on analyses of satellite imagery, the Buenos
Aires VAAC reported that on 26 November a diffuse plume from
Chaitén's lava-dome complex drifted ENE. SERNAGEOMIN suggests
maintaining Volcanic Red Alert.
As of the
25th of November 2009, SERNAGEOMIN reported that Chaitén's
seismic activity has remained similar to that of the preceding
period, with a prevalence of hybrid type (HB) earthquakes
reaching an average of 15 earthquakes per hour and with
magnitudes locally calculated to be within the range 1.5 to 4.2.
Among these 2-4 earthquakes stand out each hour with magnitudes
of above 3.5. Comparing the seismicity of this period with that
of previous weeks, the seismic energy liberated RSAM has not
exceeded 150,000 units. Both visually and seismically no large
changes have been shown, and activity is consistent with that
which has developed during the preceding period; this indicates
that the eruptive activity continues with the growth of the dome
complex. On the other hand, the quantity of pyroclastic material
both from rock falls and emitted by the block-and-ash flows and
lateral explosions has created large accumulations in the
adjacent valleys and particularly the valley of the Chaitén
river, so that the occurrence of lahars towards Chaitén during
periods of intense rain cannot be ruled out. In consequence,
given that the seismicity remains at elevated levels – an effect
of the growth of the dome complex – and that the eruptive
activity continues with the possibility of the generation of
block-and-ash flows in random directions, which may affect
surrounding valleys with the generation of new lahars,
SERNAGEOMIN suggests maintaining Volcanic Red Alert. As of the
19th of November, SERNAGEOMIN reported that during 31 October-1
November Chaitén's lava-dome complex produced steam plumes that
sometimes contained gas and ash. The plumes were visible on the
web camera and rose at most 1 km above the lava domes.
SERNAGEOMIN bulletin of the Chaitén eruption, covering the
period 16-30 September 2009, reported the results of an
overflight carried out on 29 September. Among the interesting
facts reported there is the emergence of a new third lava dome,
the appearance of an elongated depression in the central area of
the dome complex, and a collapse event on 29 September. As of
the 1st of October, SERNAGEOMIN reported that based on web
camera views and analyses of satellite imagery, the Buenos Aires
VAAC reported that on 28 September a diffuse ash plume from
Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex,
possibly mixed with steam and gas, rose to an altitude of 2.4 km
(8,000 ft) a.s.l. The plume drifted less than 40 km W and SW. As
of the 24th of September, SERNAGEOMIN reported that during 1-16
September, Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex
continued to grow. The Alert Level remained at Red. Based on web
camera views, SIGMET notices, and analyses of satellite imagery,
the Buenos Aires VAAC reported that during 16 and 20-22
September ash plumes rose to altitudes of 1.8-2.4 km
(6,000-8,000 ft) a.s.l. and drifted NE, E, and SE A s of the
21st of August, SERNAGEOMIN reported that the images observed
through the DGAC camera, located in Chaitén to the south of the
volcano, show that the eruption has continued in an unchanging
form with its column of gas and ash which has occasionally risen
to 1.5 km above the dome complex. At times it has been possible
to distinguish a secondary and intermittent centre of emission
to the west, very close to the principal centre of emission. The
block-and-ash flows still persist, indicating that the dome
complex continues its growth, particularly towards the western
sector of the caldera. .As of the 6th of August, SERNAGEOMIN
reported that based on web camera views from the S, and analyses
of satellite imagery, the Buenos Aires VAAC reported that during
29 July-1 August, and on 4 August, ash plumes from Chaitén's
Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex rose to
altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted N,
S, and SE. As of the 26th of July, SERNAGEOMIN reported that
seismicity has remained high at Chaiten volcano, Chile, during
the period 16-22 July. The eruption continues unchanged with a
column of ash and steam rising 1.5 km above the summit. Block
and ash flows still persist, indicating the dome complex has
continued to grow, particularly towards the western sector of
the caldera. Some strong emissions of gas correlated with
seismic activity. Dome collapse remains a danger and may affect
adjacent valleys. Significant pyroclastic material has
accumulated in the adjacent valleys, and pose a lahar risk after
heavy rain. Alert level RED remains at Chaiten volcano due to
continued dome growth, pyroclastic flow risk, and potential for
lahars. The Alert Level remained at Red. Based on web camera
views, analysis of satellite imagery, and a SIGMET notice, the
Buenos Aires VAAC reported that on 11 and 14 June ash plumes
from Chaitén's Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex
rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and
drifted NE and SE. A thermal anomaly was also seen in satellite
imagery on 11 June. Based on web camera views, SERNAGEOMIN
reported that during 27 May-8 June gas-and-ash plumes rose 1.5
km from Chaitén's growing Domo Nuevo 1 and Domo Nuevo 2
lava-dome complex. Collapses originating from unstable slopes
generated block-and-ash flows that were sometimes seen from
Chaitén town, 10 km SW. Ashfall was occasionally reported in
Chaitén town and nearby areas. As of the 13rd of May SERNAGEOMIN
reported that during 29 April-4 May gas-and-ash plumes rose up
to 2 km from Chaitén's growing Domo Nuevo 1 and Domo Nuevo 2
lava-dome complex. Collapses originating from unstable slopes
generated block-and-ash flows. An overflight on 1 May revealed a
large central spine fractured into three main blocks. The
surface of the lava dome complex was very irregular and several
spines had grown 100 m above the dome surface. Seismicity
remained high. Based on analysis of satellite imagery, SIGMET
notices, web camera views, and information from the Puerto Montt
Flight Information Region (FIR), the Buenos Aires VAAC reported
that during 5 and 10-12 May, ash plumes rose to altitudes of
2.1-4.6 km a.s.l. and drifted N, NE,and ENE. According to
SERNAGEOMIN, since 15 April, when the energy released by the
seismicity of Chaitén volcano reached 130000 units RSAM, the
values have begun to fall slightly, remaining during Thursday 16
April 2009 at 100000 units, therefore values continuing to be
very elevated. Llaima, however, has not shown visual signs of
significant activity during past days.
As of the 2nd
of April, the Government of Chile has announced that during
17-23 March Chaitén's lava-dome complex continued to grow from
an area that includes the central spines and part of Domo Nuevo
1. This was also the main area where collapses from unstable
slopes caused block-and-ash flows. Continuously emitted steam
plumes with varying amounts of tephra and gas-and-ash plumes
generated by block-and-ash flows drifted N and ESE. The
block-and-ash flow volume was smaller compared to the previous
week. The Alert Level remained at Red. As of the 19th of March,
the Government of Chile has announced that based on web camera
views, analysis of satellite imagery, and SIGMET notices, the
Buenos Aires VAAC reported that during 11-15 March ash plumes
from Chaitén rose to altitudes of 2.1-3.7 km (7,000-12,000 ft)
a.s.l. and drifted NNE, NE, E, and SE. A thermal anomaly was
detected in satellite imagery on 15 March. On 3 March during an
overflight co-ordinated with the Regional Office of ONEMI it was
possible to verify that the deposits of the block-and-ash flow
that descended through the río Chaitén on 19 February still
maintaind high temperatures in some areas, with emanations of
water vapour and even burning of trees where they had come into
contact with lava blocks from the domes, with high temperatures
(over 300ºC). The seismicity of Chaitén volcano has declined
slightly during the period in the number of larger HB-type
earthquakes, with magnitudes of between 3.2 and 3.6, in
comparison to previous days. The earthquakes that have been
recorded are principally of HB-type, which indicates the
continuing supply of magma to the dome complex. As of the 27th
of february, SERNAGEOMIN reported that another large-scale dome
collapsep at Chaitén volcano during the afternoon. Reports
mention that a large part of the northern side of the dome
collapsed and an intense plume rose from the volcano. This
collapse occurred at around 14:47 local time this afternoon. An
overflight carried out on 24 February, allowed the ovbservatin
of the current state of eruptive activity, the morphology of the
domes and the dimensions and precise location of the area
affected by the collapse that occurred last Thursday (19.02.09).
The escarpment or scar of the collapse is oriented in an
approximately south-western direction, with a greatest length of
approximately 500m and a maximum height of the of the escarpment
slopes of 200m. The area of collapse is located in the
south-western quadrant of the dome complex and affects,
approximately, some 10% of the total volume. The collapse
escarpment surrounds the south and west of the spine or pinnacle
which has grown in the central sector of the dome complex. The
majority of the material removed is from Dome 1, the development
of which began in May 2008. The northern sector of the dome
showed occasional eruptive activity, which is concentrated to
the immediate north of the pinnacle, at the pinnacle, and at a
remnant of dome 1 located to the south of the collapse
escarpment. In the northern sector, within dome 2, eruptive
activity was observed in two sectors and was manifested in the
emission of water vapour with occasional ash content. The
majority of the eruptive activity was concentrated on the spine
or pinnacle, with constant emissions of brown-coloured ash and
water vapour. The southern remnant of dome 1 intermittently
emitted ash and water vapour of similar colouring to that at the
pinnacle, in addition to producing sporadic explosions.
Together, they form four eruption columns of gas and ash, which
exceed 1.5km in height and which during small collapses of the
steep slopes of the pinnacle tend to form one wide and irregular
column.As of the 19 th of February, SERNAGEOMIN reported that
there was a major reactivation of the eruption at Chaitén
volcano on the morning. Everyone still in the town of Chaitén
was evacuated, and the authorities have activated their various
emergency plans. A major partial dome collapse occured,
generating pyroclastic flows that penetrated a long way south
along the Chaitén river valley, almost reaching the town itself.
A collapse such as this is a process rather than an event, and
further collapses of the structure of the dome(s), along with
the release of overpressurized gases, is continuing to generate
further debris flows along the length of the valley. At 15:20
the same day, an overflight was carried out at Chaitén volcano,
revealing a fracture of more than a kilometre on the dome,
southern sector, with evident signs of collapse, which
constitutes, an important threat to the town of Chaitén. Large
emissions of gases and pyroclasts were also observed. Heavy
rains over the volcano could generate substantial floods,
causing further damage in the town of Chaitén. Previously on
19th of January, between 10:59 and 12:00, a major partial
collapse already occured on the steep pinnacles that form the
summit of New Dome 2 above the south-eastern flank, with the
consequent generation of block and ash flows. On 25th and 28th
December, ash emissions reached 2 km above the crater. A lava
dome continues to grow in the crater, producing instability on
the summit and flanks. Explosions from the lava dome are
possible and create the risk of pyroclastic flows. The volcano
remains at the highest alert level red.
As of the
15th of December SERNAGEOMIN reported that explosive events that
have characterized Chaitén's recent activity took place
yesterday, 14 December 2008, beginning at around 13:19 local
time. The explosion, which appears to have been related to a
partial collapse within the caldera, generated a large ash plume
which reached hundreds of kilometres south-east into Argentine
territory As of the 11th of December, SERNAGEOMIN reported that
based on on observations of satellite imagery, pilot reports,
SIGMET notices, and web camera views, the Buenos Aires VAAC
reported that during 3-8 December, ash plumes from Chaitén rose
to altitudes 1.8-4.6 km (6,000-15,000 ft) a.s.l. and drifted NE,
NW, and SW. A thermal anomaly was detected on satellite imagery
during 4 and 6-8 December. Gaseous emissions have been observed
both from the growing New Dome 2 (north-east sector) and from
New Dome 1, on its southern flank, which has almost completely
covered the old dome. The emissions have shown a predominance of
water vapour, even when occasional increases in the emission of
volcanic gases have been seen, with changes in the colour of the
columns emitted from New Dome 2, depending on variations in the
concentration of ash. The columns of gases observed have reached
heights of between 1.5 and 2.5 kilometres above the domes.On
Saturday 6 December an overflight of Chaitén volcano was carried
out and In the interior of the Chaitén caldera it was possible
to see clearly the remnants of the old dome, almost completely
buried by the viscous lava of New Dome 1 (coloured red-brown).
Very notable were the dimensions reached by New Dome 2 (colour
grey) located in the north-east sector of New Dome 1, where the
eruptive activity was concentrated, consistent with the evident
extrusions of viscous lava forming very unstable pinnacles and
ridges, with constant landslides on their sloping sides, which
rest on the internal wall of the caldera. Additionally, from two
points on its uneven crest, constant emissions of volcanic gases
are generated, with a predominance of water vapour. On 29
October, SERNAGEOMIN received reports of an increase in activity
at Chaitén characterized by several explosions that darkened the
plume and caused it to rise from about 1.6 km (5,200 ft) a.s.l
to about 3.1 km (10,200 ft) a.s.l. SERNAGEOMIN reported that
variations in seismicity remained similar to patterns detected
during the pervious weeks. A gas plume was continually emitted
to an altitude of 3.1 km (10,200 ft) a.s.l. during the previous
week. ONEMI reported that during an overflight on 30 October,
scientists observed a landslide that had originated from the
active lava dome. As of the 20th of October, SERNAGEOMIN
published a new report for the period between 13th -17th of
October : during this period two eruptive columns have been
maintained of no more than 2.0km in height, principally formed
of water vapour with a relatively low content of sulphur dioxide
and ash, moderately vigorous, white and relatively wide, with
dispersion mainly towards the southeast. HB-type earthquakes are
continuing without variation in quantity and magnitude. The
eruptive activity is related to degassing and the generation of
water vapour through rainwater coming into contact with the hot
dome and/or remnants of magmatic material in the upper levels of
the system. The seismic activity is related to the growth of the
dome. In the short term, a possible reactivation of the eruptive
process can be ruled out. SERNAGEOMIN maintains Volcanic Red
Alert.SERNAGEOMIN reported that during 7-13 October a
gas-and-ash plume from Chaitén rose to an altitude of 3.1 km
(10,200 ft) a.s.l. The Volcanic Alert level remained at Red.
Based on web camera views, Puerto Montt Flight Information
Region (FIR) notices, analysis of satellite imagery, and SIGMET
reports, the Buenos Aires VAAC reported that during 12-14
October, continuous ash plumes from Chaitén rose to altitudes of
2.4-4 km(8,000-13,000 ft) a.s.l. and drifted N and E. As of the
9 th of October, SERNAGEOMIN reported that during an overflight
on 30 September, scientists observed the small lagoon that
remained in a depression in the N area of the basal "ring" that
lies between the new lava dome and the caldera rim. The base of
the S flank of the old lava dome was still evident; fumaroles
were noted along the contact of the old and new domes. The new
lava dome had grown higher and laterally from the NE flank until
it touched the caldera rim. The Alert level remained Red. Based
on pilot observations, analysis of satellite imagery, and SIGMET
reports, the Buenos Aires VAAC reported that during 3 and 5-8
October continuous ash plumes rose to altitudes of 2.4-3.5 km
(8,000-11,500 ft) a.s.l. and drifted NE, ENE, and E. As of the
29th of September, SERNAGEOMIN reported that eruptive activity
returned to levels comparable to those reported in previous days
up to the end of last week, that is with columns of a maximum of
1.5km in altitude, weak and of little vigour, with a
predominance of water vapour over gases and ashes, dispersing
towards the north-east. Since the 26th of this month, the
earthquakes of greater magnitude, interpreted as HB-type, have
increased their energy to reach, in some cases, magnitude 3.5M.
The earthquakes of HB-type recorded by the stations in the
vicinity of the volcano (e.g. Pumalín, Pillán and Santa Bárbara)
remain at depths calculated as approximately between 2.0 and
5.0km, with epicentres located, also about, at 3.0km south of
the volcano. The earthquakes of greater magnitude have been
registered as far as the seismic monitoring stations at Llaima
volcano, located 457km to the north. SERNAGEOMIN maintains
Volcanic Red Alert. SERNAGEOMIN report on the eruptive activity
of Chaitén volcano between 23 and 24 September 2008 noted that
eruptive activity contines with a column that does not exceed
1.5km in altitude, with a predominance of water vapour over
pyroclastic materials, principally ash. A level of 3-4 HB-type
earthquakes per hour has been maintained, some with magnitudes
around 3.0M, and there have been sporadic small VT-type
earthquakes, under 1.0M. The HB earthquakes reflect magmatic
activity and the fracturing of rock, probably in superficial
levels of the system - it is hoped to clarify the precise depth
very soon. SERNAGEOMIN maintains Volcanic Red Alert.From
Saturday 6 September until Monday 8 September, poor weather
conditions did not permit visual observation. During this
period, the seismicity has remained mainly similar to that
recorded during the two previous weeks, that is 6 to 8 HB-type
earthquakes per hour with a slight oscillation in their
amplitude, and 1 to 2 VT-type earthquakes per hour, with maximum
magnitude of 2.9M, in addition to rare LP-type earthquakes of
low energy and short duration. Both the HB and VT earthquakes
have presented very similar times of arrival of 's-p' waves,
which establish distances of 23-25km from PUMA station and
15-16km from STBA, placing their epicentres 2-5km south-east of
the volcano. As of the 4th of September, SERNAGEOMIN reported
that clouds obscured camera views of Chaitén's eruption plume
during most of 26-29 August. Glimpses utilising the web camera
revealed that continuous ash plumes rose to an altitude of 1.5
km (4,900 ft) a.s.l. and drifted SW. They also reported that
seismicity had increased slightly during the previous few days.
Based on web camera views and analysis of satellite imagery, the
Buenos Aires VAAC reported that during 27-29 August ash plumes
rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. and
drifted SE. Between 27 and 29 August, seismic activity
continued, showing a slight but steady increase. On both 28 and
29 August the increase mentioned was reflected mainly in an
increase in amplitude of the HB-type earthquakes (increased
seismic energy), which maintained relatively constant numbers
(about 4 events per hour). For their part, the VT-type
earthquakes showed a slight decline (one per hour). However,
during these days, significant LP-type earthquakes were
registered (about 5 per day), which are emphasized by their
greater amplitude in the seismogram As of the 28th of August,
SERNAGEOMIN reported that on web camera views, pilot
observations, and analysis of satellite imagery, the Buenos
Aires VAAC reported that during 20-23 and 26 August ash plumes
from Chaitén rose to altitudes of 2.1-3 km (7,000-10,000 ft)
a.s.l. and drifted SE, E, and NE. A thermal anomaly over the
lava dome was detected on satellite imagery during 22-23 August.
As of the 22nd of August, SERNAGEOMIN reported that during
recent days the eruptive activity of Chaitén volcano has
remained without major changes, manifesting itself through a
moderately vigorous eruption column, of around 2km altitude,
with emission of pyroclastics material, gases and water vapour.
The seismic behaviour of the emission centre, for its part, has
presented a decreasing trend, without resulting in a significant
diminution of the eruptive activity, as in previous periods.
Notwithstanding the foregoing, the recorded seismic movements
could be interpreted as indicative of the movement of magmatic
fluids and rupturing of rocks inside the volcanic system.
SERNAGEOMIN bulletin about the Chaitén issued on 12 August 2008
reported that poor weather conditions preventing direct
observation of the volcano, except on the morning of 8 August
when a continuous emission of gas and pyroclasts was observed
‘which generated an eruptive column of more than 1 kilometre in
height that dispersed towards the east. An increase in the
number and magnitude of volcanic-tectonic (VT) earthquakes was
recorded over the preceding 24 hours, along with a 'sporadic
appearance' of hybrid (HB) and long period (LP) earthquakes and
an increase in background tremor, ‘phenomena attributed
principally to the ascent of magmatic fluids'. The bulletin ends
by suggesting that the characteristics of this seismic behaviour
can be interpreted as indicators of internal activity within the
system that, eventually, could manifest in increases in the
eruptive activity of the volcano. Following a meeting,
USGS/USAID reported some details about the activity until end of
July and in particularly there is fresh information on the lava
dome :giving the following estimates for the end of July:
average lava dome eruption rate ~60m 3 /s (the average given in
June was ~37m 3 /s), area ~1.4 million m 2 (area given in June
~540,000m 2 ) volume ~350 million m 3 (volume given in June ~55
million m 3 ) -
Previous news
reportd that an explosive eruption appears to have taken
place at Chaitén on 1st of August in the morning. This was the
webcam image at 08:59 (local time): a sizeable eruption under
way at the caldera. More following images indicated that the
eruption has subsided, with a lighter, thinner plume (but still
larger than anything we saw yesterday) and less evidence of
heavy ash content. The latest bulletin (issued this same day at
11:20 local time, noted that an overflight yesterday ‘detected
partial collapses in the central part of the new dome' and the
removal (through collapse) of some of the material of the dome.
As of the 29 th of July, SERNAGEOMIN reported that, available
records indicate weak eruptive activity, which has shown a
modest upswing in the last few days without giving rise to a
significant eruption column. In general terms, the declining
trend appears to continue on course. The weather conditions have
not permitted observation of the volcano, except for short
periods in which the cloud has left uncovered an eruption column
that does not surpass a kilometre in altitude above the summit
of Chaitén. Moreover, intense and continuous noise has been
perceptible since 24 July, when an emission of ash accumulated
to the depth of 3cm around Chaitén. On 27 July weather
conditions again favoured the fall of fine ash on the town,
albeit in a very restricted manner. The foregoing
notwithstanding, the latest seismic data clearly shows an
elevated seismicity, which has been sustained for several weeks,
both in the number of earthquakes and their magnitude (a large
number of them being felt by people over several days) and
recorded by stations at a distance, with an increase in the
number of earthquakes with a magnitude greater than 3.5M.
Likewise, it was possible to verify that the greater part of the
earthquakes of greater energy were located to the south-east and
south-south-east of the Chaitén volcano. On 24 July, during an
overflight conducted over sectors north and north-east of
Chaitén volcano, it was observed that there is only one
principal eruptive centre in the southern sector of the new
dome. This centre produces an intermittent eruption column, with
periodical increased activity which forms a more substantial
column, although one lacking density and of relatively low
altitude (less than 2km) whch disperses rapidly towards the
south and south-east. That column caused poor visibility at
altitude, and was occasionally crossed by more energetic and
denser columns, related to slightly more intense explosions
alternating with the intervals of lesser eruptive power which
did not produce any proper column. The emission in this case was
white in colour, mainly produced by degassification and water
vapour, with a low percentage of ashes. It was also apparent
that the morphology of the new dome has changed, presenting a
major depression in the southern sector, immediately to the
north of the principal eruption centre from which abundant water
vapour and gases are emitted. At the same time, this structure
[i.e. the new dome] appears to have decreased its rate of
growth, at least in the northern sector, and significant
emissions of water vapour and gases can be observed from the
base of the eastern sector of the dome. Regarding seismic
activity, during 24 July there was a decrease in the total
number of earthquakes and a stabilization, it appears, in the
number of earthquakes of greater magnitude. Notwithstanding the
foregoing, earthquakes of this type are still being detected by
instruments located nearly 300km from the volcano. The
significant increase in earthquakes of greater magnitude
(greater than 2.6) may imply that the ascent of a new pulse of
magma has begun, from depths greater than 10km. Previously,
based on observations during an overflight on 17 June,
scientists of SERNAGEOMIN reported that ash plumes emitted from
the S contact between Chaitén's old and new lava domes rose to
an altitude of 2 km (6,600 ft) a.s.l. and drifted N and NW. An
explosion temporarily propelled the ash plume to an altitude of
3 km (10,000 ft) a.s.l. and steam plumes rose from several other
contact points along the S edge of the lava dome. Rockfalls from
the active dome continued to descend the S flank of the old dome
to the caldera floor. During 18-21 June, visual observations
were inhibited due to inclement weather. During 18-20 June,
possible ashfall was reported in Queilén (about 70 km W) and
Quellón (about 80 km WSW). Ashfall was reported in Chaitén town
(10 km SW) and other areas SE, W, and E. Another overflight on
14 June revealed spines rising above the top of the new lava
dome, which had grown in height to exceed the old dome. Gas,
ash, and steam plumes were primarily emitted from a vent, about
100 m in diameter, at the SE contact between the old and the new
lava dome. Previously, emissions came from the NW contact
between the old and new domes. Continuous explosions produced
ash plumes that rose to an altitude of 3 km (10,000 ft) a.s.l.
and drifted E. Several other points of gas-and-steam emissions
were seen along the contact. Small block-and-ash flows from the
new dome had descended the S flank of the old dome and
occasionally reached the caldera floor. The Alert Level remained
at Red Chaitén volcano in southern Chile has now been erupting
for six weeks, and seemed over the last few days to be still
active. However, latest reports suggest renewed gas and ash
emissions, loud rumbles, and the appearance of two new craters.
According to a new bulletin issued by SERNAGEOMIN during
evening. On 13 June 2008 the Volcano Disaster Assistance Program
of the USGS gave further information about the Chaitén eruption
that Some of the interesting points to emerged as follows :
current lava dome eruption rate estimated to be greater than 50m
3 /s (average ~37m 3 /s); area : 540.000 m2 (900 x 600 m);
volume : about 55 million m3. On 12 June people stationed in the
town of Chaitén reported new emissions of gas and pyroclasts
coming from the south flank of the old volcanic dome and
‘reported that noises were heard coming from the volcano during
11 and 12 June. The source of the emissions was identified as
two new craters at the base of the southern flank of the old
dome. The Chaitén river produced renewed flooding in the town on
the evening of 12 June. The seismic activity increased after the
morning of 12 June, both in the number of earthquakes and in the
seismic energy that they released. The majority of the
earthquakes of less than magnitude 2 were located under the
volcano, while two more significant earthquakes were located 5km
to the north-east, with epicentres located on one of the lines
of the Liquiñe-Ofqui fault system. As of the 10th of June
SERNAGEOMIN that in the last few days, the eruptive activity of
Chaitén volcano has remained in patterns similar to those
reported during the previous week, that is to say, the volcano
continues, but with low intensity. The dome currently maintains
its rapid growth and, probably, will continue in this way for
weeks or months. The explosivity and discharges of ash have
gradually decreased and are now manifested only in a
dispersion plume which does not exceed 3km in altitude, without
a true eruption column, accompanied by abundant emissions of
water vapour.
As of the 3rd
of June SERNAGEOMIN reported that during Sunday 1 June, because
of the distribution of the plume, fine ash and volcanic dust was
precipitated across the central-eastern area of Chiloé island
(Queilen, Lelbún, Chonchi, Dalcahue and Castro), among other
areas. Due to these conditions it proved impossible to advance
the consolidation of the seismic monitoring network. On Monday 2
June a dense fog affected the Corcovado Gulf, and especially the
coastal area of continental Chiloé, due to the stirring up of
the ashfall by the wind. However, a distant inspection flight by
helicopter showed that the volcano's eruption column was
reaching an altitude of no more than 3km above sea level and
that the plume was dispersed in a south-south-easterly
direction.
Seismic
activity shows a slight increase in comparison with previous
days, reflected in a larger number of VT [volcano-tectonic]
earthquakes and LP [long period] type earthquakes. The latter
are interpreted as being caused by the movement of fluids and/or
pressurization in the upper conduit. Thus, from 1 to 2 June
Auchemó and Santa Bárbara seismic stations registered an average
of 5 VT-type earthquakes per hour, with magnitudes of less than
2. In addition both stations observed, although in a very
sporadic form, LP-type events of short duration (less than 60
seconds). As of the 26th of May SERNAGEOMIN reported that the
eruptive activity of the Chaitén volcano has declined to
subplinian type, but remains continuous', and that over the
weekend, and in particular on Sunday 25 May, the eruption column
reached an average altitude of less than 3.5km above sea level,
with occasional large explosions lifting it to around 5km above
sea level. South-westerly winds pushed the plume in a
north-easterly direction.An overflight took place on 24 May,
during which it was possible to overfly the volcano's crater and
examine the slight growth of the active volcanic dome,
which just rises above the summmit of the old dome'. South of
the active dome is a 200-metre crater ‘from which there is a
continual expulsion of gas and ash'. The new dome ‘generates,
especially to the north, flows and blocks of ash, because of the
instability of its steep walls'. A second overflight carried out
by a Navy helicopter on 25 May revealed that many of the rivers
in the Chaitén region are carrying significant quantities of
ash. Seismic activity is currently declining over the past four
days VT-type [volcano-tectonic] earthquakes have decreased
gradually in number and magnitude, indicating a slight but
steady decay of seismic activity.As of the 22nd of May, the
Servicio Nacional de Geología y Minería reported, following an
overflight of Chaitén volcano, that the eruptive activity of the
Andean massif continues and that a phase of dome construction
has begun inside the active crater. The current increase in
seismicity corresponds to small internal collapses in this dome.
The burden of pyroclastic material being carried by the Río
Blanco will continue to be deposited on the city of Chaitén.
Since yesterday the remote monitoring instruments installed by
the U.S. Geological Survey (USGS) in Chumilden and Auchemó are
in operation, jointly monitored from Queilén by the USGS and
SERNAGEOMIN. All the people evacuated from the town of Chaitén
who were in shelters have been relocated to rented houses or
cabins in the cities of Puerto Montt, Osorno, Castro and
Quellón. Previous news - 16th of May: t he plinian eruptive
activity of the volcano Chaitén is continuing, and over the last
two days the column of gases and ashes has been maintained at an
altitude not exceeding five kilometres above sea level. Chaitén
volcano showed increased activity onThursday 15 May 2008, with
heavy ashfall, loud noises and many earthquakes. At 07:30, the
upper section of the volcano's eruption column was observed,
reaching an altitude of four kilometres above sea level. The
plume was directed towards the north-east due to strong
south-westerly winds of up to 140 km/h.
Since late
yesterday a light ashfall has been occurring in some sectors of
Chiloé Island, principally affecting the islands of Butacheque,
Metaluf, Quenac and Tac and the communes of Quemchi, Achao,
Castro, Chonchi and Queilen. Municipal teams are distributing
masks in the sectors concerned. The Oficina Nacional de
Emergencia (ONEMI) reported that military personnel in Chaitén
‘perceived loud noises coming from the volcano, abundant
ashfalls and electrical discharges around the top of the
mountain'. Heavy cloud cover and rainfall prevented observation
of the eruption cloud. The ONEMI bulletin also confirms earlier
reports that 90% of the town of Chaitén is flooded.An Oficina
Nacional de Emergencia (ONEMI) bulletin was released late
yesterday, 12 May 2008. The volcano was still producing a large
eruption column, which at the time of the bulletin was being
blown to the north-east. It is expected that the wind will back
to the north-west for the next few days, changing the alignment
of the eruption plume, towards the south-east. This means that
Futaleufú is in danger of further ashfalls. The volcano remains
continually active with emissions of ash toward the north-east.
An overflight by SERNAGEOMIN during this afternoon indicated
that the eruption column reaches a height of 8 kms. For the next
few days the skies are expected to be filled with rain and
north-west winds of 40-60 km/hr, meaning that the ashes will be
displaced towards the south-east affecting the Futaleufú area
and Argentina, according to information provided by the
Dirección Meteorológica de Chile. The bulletin also notes that
the Chaitén River (or Río Blanco), which crosses the city, broke
its banks for a distance of about 200 metres and flooded 40
homes. The entire mouth of the river is blocked by ash and
pumice. The flow of the river has now returned to normal levels.
Previous information : as of the 9th of May the Chaitén volcano
continues to erupt ash and the 50 kilometres security exclusion
zone around the volcano remained in force, reported ONEMI in a
bulletin of 9 May 2008. On 8 May the volcano was hidden from
view between 07:15 and 15:15 hrs. During this period, despite
the low cloud cover, grey swirls were clearly seen along the
north-south valley immediately east of the volcano Chaitén
which drains into the Rayas river, descending towards the river
and producing marked evaporation in the north-south valley. This
phenomenon is interpreted as being caused by small pyroclastic
flows that descend from the volcano into this valley
and, heating the river water, produce the resulting evaporation.
Between approximately 15:00 and 16:30 hours the prevalent cloud
dissipated allowing observation of the volcano and the
mushroom-shaped column of gases and ashes, which reached an
altitude of 14 km at 16:00 hrs, with a plume dispersing in a
north-eastern direction. Moreover, the western part of the
column of ash was more dense and of a medium to dark grey
colour, which could be due to the opening of a new crater on the
western side of the dome. Previous information reported that t
he Chilean volcano Chaitén intensified its activity around
midnight on Wednesday 7th/8th of May expelling ash and
incandescent material, forcing the evacuation of all the
military personnel and about 10 civilians who remained in the
town closest to the peak. In the southern town of Chaitén, only
10km from the volcano, the total evacuation was ordered after
pyroclastic material was seen to emerge from the cone of the
volcano for a few minutes followed by dense columns of ash that
fell on the surrounding area. ‘Army personnel have seen
pyroclastic material, incandescent material, and there has been
an increase in the sulphurous smell present in the town of
Chaitén. As of 6th of May, latest SERNAGEOMIN bulletin online
reported that eruptions continue for at Chaitén volcano. There
have also been reports of a sharp increase in earthquakes in the
area since the eruption. Evacuations have occurred at a second
town, Futaleufu. Some residents have evacuated across the border
to Argentina. Around 25,000 head of cattle in the area are in
serious danger of dying. According to SERNAGEOMIN, during the
morning of 6 May, at 08:20, the eruptive cycle went through a
recrudescence with vigorous and rhythmic explosions of great
energy producing a much wider laterally expanding eruptive
column of about 30 kilometres altitude in its initial phase,
declining subsequently. A subsequent helicopter overflight found
that two craters on the northern side of the dome had joined
into one, 800m-wide vent during this eruptive phase. (Assuming,
as appears to be the case from photographs, that the
initial site of the eruption was on the southern flank of the
dome, it now seems that the volcano is erupting from both
northern and southern flanks.) No pyroclastic flows were
reported to the north, south or west (the eastern zone could not
be inspected, presumably, being obscured by the eruption plume),
and it was noted that the rivers around the volcano were
carrying a greater load of erupted material. Overall SERNAGEOMIN
considers that the eruption may develop in two ways from this
point onwards - although, as always with predictions of volcanic
activity, it is impossible to be sure. There is the possibility
of a collapse of the eruptive column and/or the rhyolite dome,
which would generate pyroclastic flows. On the other hand the
fall of ashes may continue with accumulations whose thickness
will depend on the intensity of the explosions and the
prevailing winds. President Michelle Bachelet briefly visited
Chaiten and spoke with some of the few remaining residents. At
shelters in Puerto Montt, evacuees sought the president's
support to rebuild outside the path of the volcano. Most of
Chaiten's 4500 residents fled as the eruption polluted air and
water supplies. As of 3rd of May bulletin, from the Chilean
Government Emergencies Office ONEMI reported that eruptive
activity was continued at the Chaitén volcano, with the sky
darkened by ash and a constant fall of fine ash in nearby areas.
A sulphurous smell has been reported in some districts. A number
of earthquakes have also been experienced in the region over the
past 24 hours. The volcano was still ‘erupting ashes' and
covering the surrounding districts ‘with a dense cloud of ash
more than 20km in height … In Chaitén town, the streets are
covered with 20-40cm of ash'. The fall of ash from Chaitén is
also causing problems in neighbouring areas of Argentina, where
airports and schools have been closed, transport disrupted and
water supplies affected. In the same bulletin ONEMI also reports
that the evacuation of Chaitén is continuing, with the aim being
to evacuate the whole population: From yesterday to dawn today a
total of 3900 people have been evacuated by sea from Chaitén to
Puerto Montt and Castro, which corresponds to 89% of the
population … Today approximately 500 people will be evacuated on
six vessels bound for Castro and Puerto Montt. This will
evacuate the entire population of Chaitén. Previous news :
following a short seismic crisis, the Chaiten volcano started an
eruption. The Chaiten volcano ejected gas and ash on Thursday
night 1st to 2nd of May 2008, causing more than 60 small tremors
in the Los Lagos region, 750 miles south of the capital,
Santiago.Chile's government declared a state of emergency,
evacuating as many as 1,500 people from nearby villages and the
town of Chaiten, just over 6 miles from the volcano considered
dormant for thousands of years erupted. The blast sent minor
earthquakes rippling through the region. The amount of ash
falling in Chaiten had dropped considerably by Friday afternoon,
and the wind was moving it southeast. Ash from the eruption was
polluting water supplies and prompting officials to hand out
more than 10,000 protective masks. Winds also carried ash over
the Andes mountains to neighboring Argentina, where the
Education Ministry suspended classes in several towns, including
Esquel and Trevelin - two popular Patagonian tourist.
Authorities also declared a state of alert on two major highways
as falling ash reduced visibility. On Friday evening a Volcanic
Ash Advisory stated that ash rose to altitudes in the range of
13.7-16.7 km. Chaiten lies slightly to the W of Minchinmavida.
Chaiten volcano lacks any known modern eruptions but a
radiocarbon date on its tephra (CHA1) yields a date of 7,430 BC
(plus or minus 75 years). Chaitén is a small, glacier-free
late-Pleistocene caldera with a Holocene lava dome located 10 km
NE of the town of Chaitén on the Gulf of Corcovado. The north
side of the rhyolitic, 962-m-high obsidian lava dome occupying
the 3.5-km-wide caldera is unvegetated. Obsidian cobbles from
this dome found in the Blanco River are the source of
prehistorical artifacts from archaeological sites along the
Pacific coast as far as 400 km away from the volcano to the
north and south. The caldera is breached on the SW side by a
river that drains to the bay of Chaitén, and the high point on
its southern rim reaches 1,122 m. Two small lakes occupy the
caldera floor on the west and north sides of the lava
dome.Informations :
ONEMI, GVN/GVP
-
SERNAGEOMIN (in spanish) -
Live web camera
CHILE -
Llaima volcano
March
25th , 2010
As of the
25th of April, SERNAGEOMIN reported that that the alert level
for Llaima is being raised from Yellow Level 3 to Yellow Level 4
because of ‘the occurrence of earthquakes with high energy
levels and tremor signals with durations of up to 20 minutes'.
OVDAS volcanologist Gustavo Fuentealba reported that the crater
of Llaima remains obstructed and that this ‘increases the risk
of a new eruption. There is no change in the appearance of the
volcano; fumarolic activity continues from the summit crater.
SERNAGEOMIN reported that on 4 March seismicity from Llaima
increased. During an overflight that same day, scientists
observed emissions of gas and steam from the main crater. Images
taken that day were compared to those taken on 21 February and
showed no significant changes in morphology. The rate of sulfur
dioxide emissions had increased, however. Scientists also noted
deposits from a large rockfall along with fracturing of the
glacier, especially on the upper N and NW flanks. Those
observations in addition to the increased seismicity prompted
SERNAGEOMIN to raise the Alert Level to Yellow, Level 4. The
previous SERNAGEOMIN bulletin for Llaima, released on 11
February 2010 and covering 20 January to 9 February, reported
that emissions of water vapour and occasional slight emission of
gases from the principal crater' were observed during that
period, reflecting normal degassing, but that the volcano's
seismic activity indicates a possible increase in activity in
the near future. As of the 7th of December, ONEMI has issued a
bulletin, reporting that‘a seismic swarm associated with
internal degasification and marked by increased release of the
volcano's internal energy was detected between 16:00 and 18:00
local time on 6 December. Fumarolic activity has been
continuing, and the main crater remains obstructed. ONEMI is
maintaining Yellow Alert for Llaima and surrounding communities,
and the 4-kilometre radius exclusion zone remains in force.
Previously, as of the 2nd of September 2009, SERNAGEOMIN
reported that while seismicity at Llaima volcano tended to
decrease in the early days of August, it has subsequently
increased, slightly exceeding its usual values in this latest
period (17-21 August). These oscillations in seismic activity
(LP-type earthquakes [Long Period earthquakes] of high and low
frequency) could be related to the rising and falling of the
magma column located in the principal conduit of the volcano,
demonstrating the instability of the magma column. The absence
of other types of seismic activity in this type of phenomenon
suggests the existence of an unobstructed volcanic conduit, in
which magmatic fluids can suddenly rise freely, bringing about a
new eruptive phase. Due to the markedly erratic behaviour which
the volcano has shown during recent times, it is not possible to
rule out its reactivation. Because of the foregoing, SERNAGEOMIN
continues with Green Alert level 2, maintaining a 4-km radius of
exclusion around the principal crater. The camera in Melipueco
used by OVDAS-SERNAGEOMIN to monitor Llaima again showed glow on
the NW inner margin of the main crater during 9-16 June.
Occasional steam emissions with minor amounts of ash were also
seen from the E flank. Seismic tremor has also increased since 5
June. The Alert Level remained at Yellow SERNAGEOMIN reported
that during 5-8 June incandescence from an area in the SW part
of Llaima's main crater corresponded to a small active"outcrop
of lava." On 6 June, incandescence emanated from a small point
along the E-flank fissure. Gas and steam was emitted from an
area W of the main crater. The Volcano Alert Level remained at
Yellow. On 26 May 2009, after a period of unusually heavy rain,
a 500-metre long fissure on the upper east flank of the volcano
began to emit dense clouds of water vapour. On the following
day, 27 May, small amounts of ash were observed mixed in with
the water vapour, and on 28 May the vigour of the emissions and
the ash content increased. On 1 June, after further bad weather,
the energy of the intermittent emissions along the fissure
increased. A powerful phreatic eruption began at 11:20 (local
time) on 1 June. The eruption ceased by 12:00, and during that
afternoon only one small subsequent eruption was observed. Since
the phreatic fissure eruptions began seismicity has remained at
normal levels (as measured by POVI instruments 20 km from the
volcano) but the number and energy of LP (long period)
earthquakes has increased. Previously, during 5-11 May, tephra
was ejected from an area on the E flank and, during the night,
incandescence originated from this area. During the daytime,
observers reported that an almost continuous orange brown plume
rose 200 m. The Volcano Alert Level remained at Yellow. During
7-10 April, intermittent incandescence from a lava flow at the
SW base of the pyroclastic cone was observed. Incandescent
blocks originating from the lava flow descended W. On 8 April,
gasses emitted from multiple points on the pyroclastic cone
formed a plume that drifted NE. Preliminary calculations
indicated that the height of the pyroclastic cone exceeded the
top of the main crater by 70 m, making the summit elevation
3,240 m a.s.l. During 9-10 and 13-14 April, gas and steam plumes
rose from the pyroclastic cone; views were obscured by clouds on
11 and 12 April. On 14 April, fumarolic activity from the
pyroclastic cone was again noted. The Volcano Alert Level
remained at Red. As of the 7th of April, SERNAGEOMIN reported
that at 10:00 this day it was only possible to see weak
emissions of ash and volcanic gases from various points on the
summit. The Llaima continues to erupt but with a much lower
intensity compared with the first phase. A light brown ash plume
was rising to 1 km above the summit and dispersing towards the
north-east. The volcano's seismicity has also declined. At
23:00, the energetic tremor which has been a characteristic of
the seismic behaviour of the volcano during the current eruptive
cycle suddenly declined to 300 RSAM units and 40 minutes later
had reached just 19 units, where it has remained until 10:00
today'. Werner Keller of POVI, confirmed and reported that from
around 22:25 local time the persistent seismic tremor declined
to background levels. POVI's cameras detected a slow-moving lava
flow on the western flank of the volcano early this morning. As
of the 6th of April, the eruption of Chile's Llaima volcano that
began on 3 April wass still ongoing, and characterized with
vigorous and sustained activity. The bulletin from ONEMI (5th of
April) reported that 71 people have been evacuated from 11
communities near the volcano, with red alert for Vilcún and
Curacautín, because of the danger of lahars, and yellow alert
for Cunco, Melipeuco and Lonquimay. In the previous bulletin
ONEMI had reported ash emissions to 7000 metres altitude, a
plume extending 100 kilometres to the south-east, incandescent
material being projected up to 2 kilometres from the summit,
pyroclastic flows on the western flank, and lava flowing towards
the Calbuco valley. As of the 4th of April, SERNAGEOMIN reported
that eruptive activity occured at Llaima volcano in Chile . The
Chilean Government's (ONEMI) reported the day before that from
around 20:00 local time an incandescence at the crater was
visible from the adjacent areas of Cherquenco and Vilcún, and to
a lesser extent from Melipeuco. The various emergency and civil
protection committees were duly activated. Another bulletin
reported that ‘an eruption of weak character is taking place at
Llaima volcano with small explosions and eruptions of
pyroclastic material at the level of the crater.According to
information provided by Regional ONEMI personnel on the ground
the volcanic activity has remained stable for the last four
hours, with constant explosions which reach 600 metres above the
crater; fall of ash and fine scoria has been seen in the eastern
sector, towards Laguna Verde and Conguillío Park. Furthermore, a
lava flow has been observed flowing towards Río Calbuco, Comuna
de Vilcún, with an approximate length of over 1000 metres,
following the same route as that of the 2008 eruption, which
does not have large accumulations of ice and snow. ONEMI notes
that there is a lahar risk on the Calbuco river. A number of
people who were in the Conguillío National Park when the
eruption began are safe, and evacuations will take place as soon
as possible. As of the 4th of January 2009, POVI reported that
the volcano has been very active over the Past previous days.
But, none of the surveillance satellites, with thermal sensors
on board, have detected incandescent lava during the current
eruptive cycle. This is because the explosions of lava do not
present a high frequency and do not generate incandescent
surfaces greater than 50m2. On January 3rd, between 06:08 and
20:31 local time the two monitoring cameras captured a total of
37 phreatomagmatic explosions whose plumes of gases and
particulates exceeded 100m in altitude before becoming
disconnected from their source. During this period the emissions
occurred at 23-minute intervals on average. The emissions came
from three distinct points, located in the interior of the
intra-crateral cone at the summit. At 07:59, 11:01, 11:40, 12:34
and 15:42 local time the most vigorous events of the day were
observed. At 11:01 and 15:42 local time spatters of lava
impacted the slope of the intra-crateral cone and the base of
the cone. At 16:12 local time a fall of rocks and fragments
descended the south-east flank of Pichillaima cone, the
secondary summit of Llaima volcano. As of the 25th of december,
SERNAGEOMIN reported that Since mid-December, however, the level
of fumarolic activity has increased gradually, and on 11
December two small debris avalanches descended the west flank of
the volcano, went down through a channel in the ice created by a
past eruptive activity. On 22 December there were two weak ash
emissions at 13:48 and 21:10 local time. This activity could be
a precursor to further eruptive activity in the near future.
There had been heavy snow fall on the day preceding this
activity, indicating that large volumes of melt water were
probably responsible for this phreatomagmatic activity. As of
the 26th of November, SERNAGEOMIN reported that from 19 November
to 25th of November, observers in the area of Llaima
volcanoconfirmed that the volcano presented weak and sporadic
emissions of water vapour concentrated around the two small
craters of the paired pyroclastic cones nested inside the
principal crater. Regarding seismic activity, during this period
there has been a slight increase both in the number of LP-type
earthquakes and in the energy they have released. Few episodes
of tremor, of short duration with an energy level maintained at
an average of 20 RSAM units, along with weak and occasional
emissions mainly of water vapour, allow the presumption that the
seismic activity is of superficial origin.As of the 24
September, SERNAGEOMIN reported that during an overflight of
Llaima on 12 September, scientists observed diffuse
gas-and-steam plumes emitted from the external edges of the
nested craters in the main crater. During 13-22 September,
observers in Melipeuco(about 17 km SSE) reported that sporadic
gas-and-steam plumes emanated from the main crater. During an
overflight on 21 September, steam emissions were noted from
areas on the NE and W flanks. The Alert remained at Green, Level
2. Explosions were heard during 25-28 August. On 28 August,
seismic signals indicated that gas-and-ash plumes were possibly
emitted from the pyroclastic cones in the main crater. The
Volcanic Alert Level remained at Yellow.
As of the
29th of July, SERNAGEOMIN reported that in the same way as the
previous eruptive episodes of this month, the latest occurring
on Saturday 26 July had a duration of 11.5 hours, although the
stage of the greatest intensity lasted only one hour. This
corresponds to a vigorous Strombolian-type event, effusive, with
rapid onset and decline. Also, the presence of powerful tremor
was associated with the emission of ashes, with intense ejection
of pyroclasts and a very high rate of emission of lava. At
present, Llaima volcano is in a new period of ‘calm', with weak
background tremor and few LP-type earthquakes, which are
associated with very weak degassing and movements of internal
fluids. However, it could take only a few days for a new
eruptive episode similar or greater than that of Saturday 26
July to come to pass.
As of the
24th of July, SERNAGEOMIN reported that after increased
seismicity at Llaima on the 14th of July, an ash plume rose to
an altitude of 5.6 km (18,400 ft) a.s.l. Less than two hours
later, very intense orange and red incandescence was seen
through breaks in the cloud cover near the summit and at the
base of the W flank. At 1915hrs a vigorous Strombolian eruption
ejected incandescent pyroclastic material from the N vent in the
main crater to heights of 500 m above the summit. Seismicity and
the intensity of the explosions decreased later that day. On the
15th of July, diffuse ash emissions rose to an altitude of 3.4
km (11,200 ft) a.s.l. Ash and tephra covered areas of the SSE
flank. Seismic activity decreased during 16-18 July.O n 19 July,
seismicity again increased and ash-and-gas plumes rose to an
altitude of 3.3 km (10,800 ft) a.s.l. and drifted SE. The
emissions became more intense and frequent, and one explosion
produced an ash plume to an altitude of 4.1 km (13,500 ft)
a.s.l. Ash and tephra fell on the SE flank. Later that day,
constant explosions ejected incandescent material 500 m above
the summit that fell near the crater. Steam plumes emitted from
the W flank possibly indicated the presence of a new lava flow
along with mobile incandescent blocks from a previous lava flow.
After another brief period of calm, vapour emissions increased
and were followed by strong explosions and lava flows. The Alert
level remained at Yellow. As of the 17th of July, the
SERNAGEOMIN reported that a new eruptive phase at Llaima
occurred on the 10th of July following two hours of precursory
seismicity. At 1520hrs, a vigorous Strombolian eruption ejected
incandescent pyroclastic material from two vents in the main
crater to heights of 500 m above the summit, throwing bombs to
the E, NE, and S. Lava flows also moved towards the W and S
flanks. Explosions were seen from Melipeuco, Cherquenco, El
Salto, and El Manzano. Strong activity continued for almost
three hours before decreasing. Medium to coarse ash fell in
Melipeuco (up to 1.5 mm in diameter). Red glow was seen in the
early hours of the 11th of July, and there was no eruptive
column or gas emissions. Poor weather prevented observations the
next day. As of the 3rd of July, SERNAGEOMIN reported that on
the morning of 3 July, a large column of water vapour was
observed over the western flank. An overflight inspection
confirmed that the front of the lava advancing across the flank
had generated a small lahar that because of its limited size did
not reach the headwaters of the Calbuco river. At the same time,
the seismicity for last night shows a slight upturn in the
seismic energy released. Until now there has been no report of
significant effects on the environment. The low rate of emission
of magma has not favoured the massive melting of ice or snow
with the consequent generation of lahars (volcanic floods) and
both the flow and sediment load of the rivers in the western
sector have remained stable. As of the 1st of July, ONEMI
reported that following the reactivation of the Llaima volcano
at approximately 4 AM, the active lava flow has currently
reached almost 800 meters away. The ONEMI director, who was
informed of the situation just before 4 AM this morning, stated
that the direction of the lava flow places the towns of La Selva
and Danubio at most risk, due to the fact that they are located
only 10 to 12 kilometers from the crater – which is within the
primary emergency radius that has been declared. Evacuations
have been underway, however, in the town of Los Lleuques, where
12 people were removed from the area. Llaima, near Chile's lake
region, erupted violently on New Year's Day, forcing the
temporary evacuation of some tourists and residents from the
surrounding Conguillio National Park, and then belched ash and
lava in February and March.Previously SERNAGEOMIN reported that
during 28 March-4 April, fumarolic plumes from Llaima drifted
several tens of kilometers mainly to the SE. Explosions produced
ash and gas emissions. An overflight on 2 April of the main
crater revealed that gas, pyroclastic material, and ash
emissions, occasionally accompanied by small explosions,
originated from three cones. On 4 April, several explosions were
heard and also some incandescence was reflected in a gas-and-ash
plume. As of the 27th March, the El Observatorio Volcanológico
de los Andes del Sur (OVDAS-SERNAGEOMIN) reported that fumarolic
activity from the central pyroclastic cone in Llaima's main
crater reactivated on 13 March and intensified during 15-17
March. Sulfur dioxide plumes rose to an altitude of 3.6 km
(11,800 ft) a.s.l. and drifted E. People from nearby areas
reported incandescence in the crater during 19-21 March.
Incandescent material propelled from the crater was observed at
night during 20-21 March. As of the 6th March, OVDAS-SERNAGEOMIN
reported that weak sulfur dioxide plumes from two cones in
Llaima's main crater during 26-28 February. An overflight on 28
February revealed that the internal structure of the crater had
not changed since observations on 21 February. Weak fumarolic
emissions from the main crater were noted during 2-3 March. The
Alert Level remained at Yellow.
As of the
28th February, a weak steam plumes were observed from Llaima's
main crater on 20 February. The 'a'a lava flow that traveled 2.5
km during 2-13 February varied in width between 30-40 m and was
10 m thick. On 21 February small ash plumes rose from the E and
SE flanks. Pyroclastic flows descended the E flank and possibly
down the W flank. Sulfur dioxide plumes that rose from two
craters within the main crater were visible during an
overflight. On 22 February, a seismic signal pattern similar to
that observed during a previous pyroclastic flow was noted.
Ash-and-gas plumes rose from the E flank. On 23 February, an
ash-and-gas plume rose from the SE flank. On 6 February, intense
Strombolian activity that propelled material 500 m above the
summit crater was observed. Ash-and-gas plumes from the activity
rose to altitudes of 5.1-5.6 km (16,700-18,400 ft) a.s.l. and
drifted SE more than 30 km. Multiple lava flows traveled 0.7-1.5
km W and N and generated steam plumes due to their interaction
with a glacier. Activity declined later that day. During 7-8
February, explosions from two different areas in the main crater
produced brown and gray ash-and-gas plumes that rose to
altitudes of 4.1-6.2 km (13,500-20,300 ft) a.s.l. and drifted 20
km NW. Incandescent blocks from lava-flow fronts rolled down the
flank. As of the 8th February, eruptive activity at Llaima
continued from the main crater and from multiple areas on the E
flank during 30 January-4 February. Lava flows extended about
1.5-2 km in length and caused strong steam plumes due to their
interaction with a glacier. On 3 February, material from intense
Strombolian activity was propelled 500 m above the crater floor
and fell inside and outside of the crater. Multiple lava flows
from the W edge of the main crater descended about 150 m.
Incandescent blocks from lava-flow fronts rolled down the flank.
Plumes rose to an approximate altitude of 4.6 km (15,100 ft)
a.s.l. and drifted WNW. Lava flows originating from a lava lake
were observed during an overflight. These flows extended about
1.5-2 km in length and caused strong steam plumes due to their
interaction with a glacier. According to a news article, about
20 people were evacuated from an area of La Selva, in the
community of Vilcún (43 km W). Activity was similar on 4
February. A phreatic explosion on the E flank was accompanied by
steam plumes and a small pyroclastic flow. Orange ash emissions
were noted from the S lateral fissure. Ash plumes from the main
crater rose to an altitude of 6 km (19,700 ft) a.s.l. and
drifted E. Based on pilot observations, the Buenos Aires VAAC
reported that ash plumes rose to altitudes of 4.6-6.7 km
(15,000-22,000 ft) a.s.l. and drifted SE, NE, and W during 5-6
February. As of the 24th January, SERNAGEOMIN reported that
eruptive activity at Llaima continued from the main crater and
from two craters and a fissure on the E flank during 16-21
January. Based on observations during an overflight on 16
January, three nested pyroclastic cones within the main crater
were active. The larger cone produced weak ash emissions that
rose about 500 m. Ash emissions were also noted from a crater on
the E flank. Glaciers on the NE slope and W flank were fractured
and dislocated. Ash emissions from a NE-SW-trending fissure
about 80 m in length and 10 m wide were observed. Also noted
were incandescent rocks that rolled from the NE end of the
fissure and ash plumes generated from rolling rocks in multiple
areas during 16-17 January. On 17 January, ash emissions rose
from the main crater to an altitude of 3.5 km (11,500 ft) a.s.l
and drifted E. Weak Strombolian activity was seen from the main
crater during aerial observation. of the 17th January,
SERNAGEOMIN reported that seismicity from Llaima decreased in
energy, but the number of events increased during 10-14 January.
Based on seismic interpretation, weak explosions produced plumes
of gas and ash. On 11 January, lava flows on the W flank that
were observed during an overflight were cooled and snow-covered
near the crater but snow-free, and therefore still hot, about
500 m further down on the flank. Blocks of incandescent material
rolled about 1.5 km and caused steam emissions at several points
where they contacted the glacier. Ash plumes drifted NE.
Abundant cracks in glaciers to the SW of the crater were noted.
Based on observations of satellite imagery and pilot reports,
the Buenos Aires VAAC reported that ash plumes rose to an
altitude of 5.5-6.7 km (18,000-22,000 ft) a.s.l. and drifted NE
and SW on 11 and 13 January, respectively. s of the 4th January,
INGEOMINAS reported that rescue workers evacuated 54 tourists
and staff from a Chilean wilderness park on Wednesday after one
of the country's largest volcanoes erupted, spewing ash and
molten lava. There were no reports of injuries or damage, but
dozens of tourists were evacuated from the base of the Llaima
volcano after it erupted on Tuesday evening . The 54 people
rescued had been stranded overnight after a local river swelled
with meltwater and cut off road access. The volcano was calmer
by Wednesday afternoon but according to scientists further
eruptions were possible. The massive 3125-m-high, dominantly
basaltic-to-andesitic stratovolcano has a volume of 400 cu km. A
Holocene edifice built primarily of accumulated lava flows was
constructed over an 8-km-wide caldera that formed about 13,200
years ago, following the eruption of the 24 cu km Curacautín
Ignimbrite. More than 40 scoria cones dot the volcano's flanks.
Following the end of an explosive stage about 7200 years ago,
construction of the present edifice began, characterized by
strombolian, hawaiian, and infrequent subplinian eruptions.
Frequent moderate explosive eruptions with occasional lava flows
have been recorded since the 17th century.The Current Colour
Code for Llaima is currently at RED .
Llaima webcam
CHILE -
Melimoyu volcano
March
21st, 2010
As of the
20th of march 2010, Chile's state geological service SERNAGEOMIN
reported that three earthquakes, two of magnitude 3.3 and one
of magnitude 5.0, were detected on 17 March beneath Melimoyu.
The earthquakes, which have been felt by people in towns near
the volcano, continued at a lower level on 18 March. The
earthquakes were detected by the University of Chile's
seismological network and by the network set up to monitor the
eruption of Chaitén volcano, which is 140 km north of Melimoyu.
The foci were located beneath Melimoyu, at depths of between 3
and 22 km. As of the publication of the SERNAGEOMIN bulletin on
20 March the seismic activity was continuing with magnitudes
between 2.0 and 3.0 and frequencies of up to 2 earthquakes per
hour; during the activity of 18 March the frequency had reached
8 earthquakes per hour. However, no visual anomalies have been
detected at Melimoyu. SERNAGEOMIN has responded to this activity
with commendable speed by installing a network of six seismic
stations at Melimoyu to enable permanent monitoring of the
volcano. Melimoyu is a stratovolcano 2400 m high with an
8-km-wide, largely buried caldera located about 40 km NW of the
town of Puyuhuapi. The ice-filled caldera is drained by a
glacier through a notch in the NE caldera rim. The
basaltic-andesite volcano is elongated 10 km in an E-W direction
and has several cinder cones. A 1-km-wide crater is located at
the summit of the volcano. Two late-Holocene tephra layers have
been documented from Melimoyu. Last known eruption has been
dated 200 AD +-75 years.
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Volcan Popocatepetl - 19 December 2000 CENAPRED
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JAPAN
- Suwanose-Jima volcano (Ryukyu Islands)
May 6th, 2010
As of the 6th of May, the Global Volcanism Network (GVN) has
reported that based on information from JMA, the Tokyo VAAC
reported explosions from Suwanose-Jima on the 29th of April, and
during the 1st and 4th-5th of May. Details of possible resulting
plumes were not reported. As of the 1st of April, the Global
Volcanism Network (GVN) reported that based on information from
JMA, the Tokyo VAAC reported an explosion from Suwanose-Jima on
the 29th of March. Details of possible resulting plumes were not
reported. As of the 25th of February, the Global Volcanism
Network (GVN) has reported that based on information from JMA,
the Tokyo VAAC reported explosions from Suwanose-Jima during
17-19 and 21-22 February. Plumes occasionally rose to altitudes
of 1.2-1.8 km (4,000-6,000 ft) a.s.l. and drifted E and SE. As
of the 18th of February,that based on information from JMA, the
Tokyo VAAC reported explosions from Suwanose-Jima during 11-16
February. Details of possible resulting plumes were not
reported. Based on information from JMA, the Tokyo VAAC reported
explosions during 22-26 January. Suwanose-Jima, one of Japan's
most frequently active volcanoes, was in a state of intermittent
Strombolian activity from On-take, the NE summit crater, that
began in 1949 and lasted nearly a half century. The largest
historical eruption took place in 1813-14, when thick scoria
deposits blanketed residential areas, after which the island was
uninhabited for about 70 years. The SW crater produced lava
flows that reached the western coast in 1813, and lava flows
reached the eastern coast of the island in 1884.
JAPAN -
Shinmoe-Dake volcano (Kirishima group)
April
9th, 2010
As of the
8th of April, the Global Volcanism Network (GVN) has reported
that an explosive activity occured from Shinmoe-dake (Shinmoe
peak), a stratovolcano of the Kirishima volcano group, on the
30th of March prompted JMA to raise the Alert Level from 1 to 2
(on a scale of 1-5). Ash blanketed the ground to the W of the
crater. Kirishima is a large group of more than 20 Quaternary
volcanoes located north of Kagoshima Bay. The late-Pleistocene
to Holocene volcano group consists of stratovolcanoes,
pyroclastic cones, maars, and underlying shield volcanoes
located over an area of 20 x 30 km. The larger stratovolcanoes
are scattered throughout the field, with the centrally located,
1,700-m-high Karakuni-dake being the highest. Onami-ike and
Mi-ike, the two largest maars, are located SW of Karakuni-dake
and at its far eastern end, respectively. Holocene eruptions
have been concentrated along an E-W line of vents from Mi-ike to
Ohachi, and at Shinmoe-dake to the NE. Frequent
small-to-moderate explosive eruptions have been recorded since
the 8th century.
JAPAN -
Sakurajima volcano
May
8th, 2010
As of the
6th of May, the Global Volcanism Network (GVN) has reported that
based on information from JMA, the Tokyo VAAC reported that
during the 28th of April-5th of May explosions from Sakura-Jima
often produced plumes. Those plumes, along with ash plumes
occasionally seen by pilots, rose to altitudes of 1.2-3.4 km
(4,000-11,000 ft) a.s.l. and sometimes drifted NE, E, and SE. As
of the 29th of April, the Global Volcanism Network (GVN) has
reported that based on information from JMA, the Tokyo VAAC
reported that during the 14th-26th of April explosions from
Sakura-Jima sometimes produced plumes identified in satellite
imagery. Those plumes, along with ash plumes occasionally seen
by pilots, rose to altitudes of 1.5-3.7 km (5,000-12,000 ft)
a.s.l. and sometimes drifted in multiple directions.
As of the
15th of April, the Global Volcanism Network (GVN) has reported
that during the 7th-13th of April explosions from Sakura-Jima
sometimes produced plumes identified in satellite imagery. Those
plumes, along with ash plumes occasionally seen by pilots, rose
to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and sometimes
drifted NW, E, and SE. As of the 8th of April, the Global
Volcanism Network (GVN) reported that the Tokyo VAAC reported
that during the 31st of March - 6th of April explosions from
Sakura-Jima sometimes produced plumes identified on satellite
imagery. Those plumes, along with ash plumes occasionally seen
by pilots, rose to altitudes of 1.5-3 km (5,000-10,000 ft)
a.s.l. and drifted SW, SE, E, and NE.As of the 1st of April, the
Global Volcanism Network (GVN) has reported that the Tokyo VAAC
reported that during the 24th-30th of March explosions from
Sakura-Jima sometimes produced plumes identified on satellite
imagery. Those plumes, along with ash plumes occasionally seen
by pilots, rose to altitudes of 1.5-2.7 km (5,000-9,000 ft)
a.s.l. and drifted SW, S, SE, and E. As of the 25th of March,
the Tokyo VAAC reported that during the 17th-23rd of March
plumes from Sakura-Jima identified on satellite imagery, and ash
plumes seen by pilots, rose to altitudes of 1.2-3 km
(4,000-10,000 ft) a.s.l. and drifted SE and E. Based on
information from JMA, the Tokyo VAAC reported that during 10-16
March multiple explosions from Sakura-jima produced plumes that
rose to altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l. and
drifted N, NE, E, and SE. Pilots reported that on 11 and 16
March ash plumes rose as high as 2.7 km (9,000 ft) a.s.l. and
drifted SE and NE. As of the 11th of March, the Global Volcanism
Network (GVN) has reported that during 3-9 March, the Tokyo VAAC
reported multiple explosions from Sakura-Jima based on
information from JMA. During 3, 5-6, and 8-9 March, plumes rose
to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted
NE, E, and SE. Pilots reported on the 8th and 9th of March that
ash plumes rose as high as 3 km (10,000 ft) a.s.l. As of the
25th of February, the Tokyo VAAC reported that during 17-23
February plumes from Sakura-Jima identified on satellite
imagery, and ash plumes seen by pilots, rose to altitudes of
1.5-4 km (5,000-13,000 ft) a.s.l. and drifted NE, E, SE, and S.
As of the 18th of February, the Global Volcanism Network (GVN)
has reported that based on information from JMA, the Tokyo VAAC
reported that during 11-16 February multiple explosions from
Sakura-Jima produced plumes that rose to altitudes of 1.5-2.7 km
(5,000-9,000 ft) a.s.l. and drifted N, E, SE, and S.
Based on
information from JMA, the Tokyo VAAC reported that during 3-9
February multiple explosions from Sakura-Jima produced plumes
that rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and
drifted SE and N. On 5, 6, and 7 February, pilots reported that
ash plumes sometimes drifted SE and S at altitudes of 1.5-3.4 km
(5,000-11,000 ft) a.s.l. An eruption on the 8th of February
produced an estimated 1-km-high lava fountain, and an ash plume
with abundant lightning. Incandescent material fell onto the
flanks.
Based on
information from JMA, the Tokyo VAAC reported that during 27
January-2 February multiple explosions from Sakura-jima produced
plumes that rose to altitudes of 1.8-2.4 km (6,000-8,000 ft)
a.s.l. and drifted SE, E, and NE. During 27-29 January and 1-2
February, pilots reported that ash plumes sometimes drifted SE
and S at altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l. As of
the 28th of January, based on information from JMA, the Tokyo
VAAC reported that during 20-26 January multiple explosions
often produced plumes that rose to altitudes of 1.2-2.4 km
(4,000-8,000 ft) a.s.l. and drifted NE, E, SE, and S. On 23
January, a pilot reported that an ash plume drifted SE at an
altitude of 1.8 km (6,000 ft) a.s.l. Sakura-Jima, one of Japan's
most active volcanoes, is a post-caldera cone of the Aira
caldera at the northern half of Kagoshima Bay. Eruption of the
voluminous Ito pyroclastic flow was associated with the
formation of the 17 x 23-km-wide Aira caldera about 22,000 years
ago. The construction of Sakura-Jima began about 13,000 years
ago and built an island that was finally joined to the Osumi
Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850
years ago, after which eruptions took place at Minami-dake.
Frequent historical eruptions, recorded since the 8th century,
have deposited ash on Kagoshima, one of Kyushu's largest cities,
located across Kagoshima Bay only 8 km from the summit. The
largest historical eruption took place during 1471-76.
Sakurajima webcam
JAPAN - Fukutoku-Okanoba volcano (Volcano islands)
February 5th, 2010
As of the
5th of february, the Japanese Meteorological Agency (JMA) and
Japanese Coastguards have reported that an underwater volcanic
eruption was detected on Wednesday 3rd of February near
Minami-Iwoto island in the Pacific probably from
Fukutoku-Okanoba volcano. The Japanese Coastguard caught the
eruption on video showing steam billowing out and some dark-grey
ash erupting from the ocean. This active submarine volcano
erupted seven times since 1904. Fukutoku-Okanoba is a submarine
volcano located 5 km NE of the pyramidal island of
Minami-Iwo-jima.This is a submarine volcano which is part of the
Volcano Islands group, which is about 1000 km south of the main
Japanese archipelago. Its summit lies a mere 14 metres beneath
the surface. Water discoloration is frequently observed from the
volcano, and several ephemeral islands have formed in the 20th
century. The first of these formed Shin-Iwo-jima ("New Sulfur
Island") in 1904, and the most recent island was formed in 1986.
Fukutoku-Okanoba is part of an elongated edifice with two major
topographic highs trending NNW-SSE and is a trachyandesitic
volcano geochemically similar to Iwo-jima.
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USA -
Kilauea volcano ( Hawaian islands)
May 8th,
2010
As of the
7th of May, the Hawaiian Volcano Observatory (HVO) reports that
Kilauea volcanic activity continued at two locations. The summit
eruptive vent within Halema`uma`u Crater continued to host a
stable, crusted and circulating lava surface which produced a
strong glow that was visible from the Jaggar Museum overnight.
At the east rift zone vents, lava flowed through tubes to supply
surface flows that were active on the pali and coastal plain and
entering the ocean west of Kalapana. Lava was covering a short
section of road at the end of Highway 130 as of yesterday
afternoon. Sulfur dioxide emission rates from the summit and
east rift zone vents remained elevated. As of the 30th of April,
the Hawaiian Volcano Observatory (HVO) reported that glow from
the Halemaumau vent was visible overnight from the Jaggar
Museum. At the east rift zone, lava flowed through tubes to
supply surface flows that were slowly moving across the coastal
plain toward the coast west of Kalapana. Sulfur dioxide emission
rates from the summit and east rift zone vents remain elevated.
As of the 22nd of April, the Hawaiian Volcano Observatory (HVO)
reports that Kilauea volcanic activity continued at two
locations. DI deflation began early this morning, while the
summit eruptive vent within Halema`uma`u Crater continued to
host a circulating and spattering lava surface. Glow from the
vent was visible overnight from the Jaggar Museum. At the east
rift zone, lava flowed through tubes to supply surface flows
that are slowly moving across the coastal plain. Sulfur dioxide
emission rates from the summit and east rift zone vents remain
elevated. During 7-13 April, HVO reported incandescence from a
60-m-wide active lava surface about 200 m below a 130-m-wide
vent in the floor of Kilauea's Halema'uma'u crater. The lava
surface circulated and both rose and drained through a pit in
the cavity floor; a few times the level fluctuated between 235
and 260 m below the surface. Rocks from the vent walls fell into
the pond, causing spattering. Plumes from the vent drifted
mainly SW, dropping small amounts of ash, and occasionally
Pele's hair and Pele's tears, downwind. Measurements indicated
that the sulfur dioxide emission rate at the summit remained
elevated; 600 and 500 tonnes per day were measured on 8 and 9
April, respectively. Lava from beneath the Thanksgiving Eve
Breakout (TEB) and rootless shield complex flowed SE through the
upper portion of a lava tube system and broke out onto the
surface. Lava flows moved SE down Pulama pali.During 24-30
March, HVO reported incandescence from an active lava surface
about 200 m below a vent in the floor of Kilauea's Halema'uma'u
crater. The lava surface circulated and both rose and drained
through a pit in the cavity floor. Plumes from the vent drifted
mainly SW, dropping small amounts of ash, and occasionally
spatter, downwind. .As of the 26th of March, the Hawaiian
Volcano Observatory (HVO) reported that DI inflation and Kilauea
volcanic activity continued at two locations. At the summit, a
circulating and spattering lava surface rose and fell in a deep
pit inset within the floor of Halema`uma`u Crater and produced
glow that was visible from the Jaggar Museum. At the east rift
zone vents, lava probably flowed through tubes and fed scattered
surface flows above the pali. Sulfur dioxide emission rates from
both summit and east rift zone vents remained elevated. During
17-23 March, HVO reported incandescence from an active lava
surface about 200 m below a vent in the floor of Kilauea's
Halema'uma'u crater. The lava surface circulated and both rose
and drained through a pit in the cavity floor. A plume from the
vent drifted mainly SW, dropping small amounts of ash and
spatter downwind. Measurements on 19 March indicated that the
sulfur dioxide emission rate at the summit remained elevated at
500 tonnes per day. The 2003-2007 average rate was 140 tonnes
per day. Lava from beneath the Thanksgiving Eve Breakout (TEB)
and rootless shield complex flowed SE through the upper portion
of a lava tube system and broke out onto the surface. Thermal
anomalies detected by satellite, and visual observations,
revealed active lava flows above the pali. Incandescence was
sometimes seen from a vent low on the S wall of Pu'u 'O'o
crater. As of the 12th of March, the Hawaiian Volcano
Observatory (HVO) reported that the switch to DI inflation
yesterday afternoon has not yet resulted in increased activity
at the two eruption locations on Kilauea volcano. At the summit,
lava was only visible to an infrared camera at low levels in a
deep pit inset within the floor of Halema`uma`u Crater but it
still produced weak glow that was visible from the Jaggar
Museum. At the east rift zone vents, less lava flowed through
tubes and fed fewer scattered surface flows on the pali and the
coastal plain. Sulfur dioxide emission rates from both summit
and east rift zone vents, however, remained elevated. During 3-9
March, HVO reported an active lava surface about 200 m below a
vent in the floor of Kilauea's Halema'uma'u crater. The lava
surface circulated and both rose and drained through a pit in
the cavity floor. A plume from the vent drifted mainly SW,
dropping small amounts of ash downwind. Measurements during 4-5
March indicated that the sulfur dioxide emission rate at the
summit remained elevated at 700 - 800 tonnes per day. The
2003-2007 average rate was 140 tonnes per day. Lava from beneath
the Thanksgiving Eve Breakout (TEB) and rootless shield complex
flowed SE through the upper portion of a lava tube system and
broke out onto the surface. Thermal anomalies detected by
satellite, and visual observations, revealed active lava flows
on the pali and on the coastal plain. As of the 5th of March,
the Hawaiian Volcano Observatory (HVO) reports that Kilauea
continued activity at two locations. At the summit, lava was
frequently visible via webcam rising and falling in a deep pit
inset within the floor of Halema`uma`u Crater and produced weak
glow that was visible from the Jaggar Museum. At the east rift
zone vents, lava flowed through tubes and fed scattered surface
flows on the pali and the coastal plain. Sulfur dioxide emission
rates from both summit and east rift zone vents remained
elevated. As of the 26th of February, the Hawaiian Volcano
Observatory (HVO) reports that Kilauea was active at two
locations. At the summit, lava was visible via webcam cyclically
rising and falling in a deep pit inset within the floor of
Halema`uma`u Crater and producing a strong glow visible from the
Jaggar Museum. At the east rift zone vents, lava flowed through
tubes and fed surface flows on the pali and the coastal plain
but that have not yet reached the ocean. Sulfur dioxide emission
rates from both summit and east rift zone vents remained
elevated. As of the 23rd of February, HVO reported that an
active lava surface about 200 m below a vent in the floor of
Halema'uma'u crater was reported 17-23 February. The lava
surface circulated and occasionally spattered, and both rose and
drained through holes in the cavity floor. Bursting bubbles and
low lava fountains were also noted. A plume from the vent
drifted mainly SW dropping small amounts of ash downwind.
Measurements on 18 February indicated that the sulphur dioxide
emission rate at the summit remained elevated at 600 tonnes/day
(2003-2007 average rate = 140 tonnes/day). As of the 19th of
February, the Hawaiian Volcano Observatory (HVO) reports that DI
deflation continued and Kilauea continued to be active at two
locations. At the summit, lava was visible via webcam at the
bottom of a deep pit inset within the floor of Halema`uma`u
Crater. At the east rift zone vents, lava flowed through the
upper tube system and fed small surface flows above the pali and
on the coastal plain; there were no active ocean entries. Sulfur
dioxide emission rates from both summit and east rift zone vents
remained elevated. As of the 12th of February, HVO reported that
Kilauea was active at two locations. At the summit, lava was
visible via webcam sloshing and spattering in two openings in
the bottom of a deep pit inset within the floor of Halema`uma`u
Crater. This lava, combined with incandescence from several
other small openings, produced glow that was visible from Jaggar
Overlook overnight. At the east rift zone vents, lava flowed
through the upper tube system and fed small surface flows that
have advanced onto the coastal plain; there are no active ocean
entries. Sulfur dioxide emission rates from both summit and east
rift zone vents remained elevated. As of the 7th of February,
the Hawaiian Volcano Observatory (HVO) reports that DI inflation
started early this morning and Kilauea was active at two
locations. At the summit, lava was deep and sometimes visible
via webcam within at least three openings in the bottom of a
deep pit inset within the floor of Halema`uma`u Crater producing
glow that was visible from Jaggar Overlook overnight. At the
east rift zone vents, lava flowed through the upper tube system
and fed sluggish surface flows that advanced to the coastal
plain; the ocean entry has not been active for about 4 weeks.
Sulfur dioxide emission rates from both summit and east rift
zone vents remained elevated. If Kilauea responds to the current
DI event as the volcano has responded to past events, surface
activity may stall or continue to slow before resuming over the
next few days. As of the 3rd of February, HVO reported that
during 27 January-2 February, an active lava surface about 200 m
below a vent in the floor of Kilauea's Halema'uma'u crater. The
lava surface occasionally spattered, and both rose and drained
through a hole in the cavity floor. A plume from the vent
drifted N, NW, and W, dropping small amounts of ash, and
occasionally fresh spatter, downwind. Measurements indicated
that the sulfur dioxide emission rate at the summit remained
elevated; 400 and 1,000 tonnes per day were measured on 28
January and 1 February, respectively. The 2003-2007 average rate
was 140 tonnes per day. As of the 29th of January, the Hawaiian
Volcano Observatory (HVO) reports that another DI event started
yesterday and Kilauea was active at two vents. At the summit,
circulating and spattering lava remained within an opening in
the bottom of a deep pit inset within the floor of Halema`uma`u
Crater producing glow that was visible from Jaggar Overlook
overnight. At the east rift zone vents, lava flowed through the
upper tube system and fed at least one surface flow that
advanced to the top of the pali; the ocean entry has not been
active for about 3 weeks and it appears increasingly unlikely
that it will be reoccupied as time goes on. Sulfur dioxide
emission rates from both vents remained elevated. An active lava
surface about 200 m below a vent in the floor of Halema'uma'u
crater was observed during 20-26 January. The lava surface
occasionally spattered, and both rose and drained through a hole
in the cavity floor. A plume from the vent drifted in multiple
directions, dropping small amounts of ash and occasional fresh
spatter downwind. Lava from beneath the Thanksgiving Eve
Breakout (TEB) and rootless shield complex flowed SE through a
lava tube system. Thermal anomalies detected by satellite and
visual observations revealed active lava flows on top of the
pali from lava-tube breakouts. During an overflight of Pu'u ‘O'o
crater on 19 January scientists saw a recent but inactive lava
flow across the bottom of the crater. On 22 January a small part
of the crater rim collapsed in front of the web camera,
revealing an incandescent vent at the base of the E wall. During
23-26 January, incandescence was seen from the vent, as well as
from high on the E wall, the crater floor, and low on the S
wall. As of the 15th of January, the Hawaiian Volcano
Observatory (HVO) reported that DI inflation continued at the
summit and finally started at Pu`u `O`o. At the summit, lava was
visible via webcam spattering and slowly rising out of an
opening in the bottom of a deep pit inset within the floor of
Halema`uma`u Crater producing glow that was visible from Jaggar
Overlook overnight. Although inflation has started at Pu`u `O`o,
lava has not yet resumed flow from the east rift zone vents.
Sulfur dioxide emission rates from both vents probably remain
elevated. As of the 8th of January, HVO reported that Kilauea
continues to erupt from two vents. At the summit, lava was
visible via webcam at the bottom of a deep pit inset within the
floor of Halema`uma`u Crater and its glow was visible from
Jaggar Overlook overnight. Lava from the east rift zone vents
started back into the tube system early this morning. Sulfur
dioxide emission rates from both vents probably remain elevated.
As of the 31st of December, the Hawaiian Volcano Observatory
(HVO) reports that Kilauea continued to erupt from two vents; a
DI event started yesterday morning. At the summit, roiling,
receding lava at the bottom of a deep pit inset within the floor
of Halema`uma`u Crater still provided glow from the pit
overnight. On the east rift zone, lava continued to erupt from
the TEB vent and flow through tubes to the ocean just west of
Kalapana; surface flows were active. Sulfur dioxide emission
rates from both vents remain elevated. As of the 25th of
December, the Hawaiian Volcano Observatory (HVO) reported that
Kilauea continued to erupt from two vents. At the summit,
sloshing lava was visible within a single opening at the bottom
of a deep pit inset within the floor of Halema`uma`u Crater
providing glow from the pit overnight. On the east rift zone,
lava continued to erupt from the TEB vent and flow through tubes
to the ocean just west of Kalapana. Sulfur dioxide emission
rates from both vents remain elevated. As of the 18th of
December,HVO reported that Kilauea continued to erupt from two
vents-one in Halema`uma`u and the other on the east rift zone.
Sulfur dioxide emission rates from these two vents remain
elevated. At the summit, a small ponded lava surface and
spattering was visible at the bottom of a deep pit inset within
the floor of Halema`uma`u Crater, resulting in glow above the
vent overnight. On the east rift zone, lava erupting from that
vent continued to flow through tubes to the coast where it
entered the ocean just west of Kalapana. As of the 11th of
December, the Hawaiian Volcano Observatory (HVO) reports that a
DI event started this morning as Kilauea continued to erupt from
two vents. At the summit, glow continued from openings in the
floor of a deep pit in the floor of Halema`uma`u Crater. Sulfur
dioxide emission rates from the Halema`uma`u and east rift zone
vents remain elevated. From the east rift zone vent, lava flows
through tubes to the coast and is entering the ocean at several
locations west of Kalapana. Last 24 hours at Kilauea summit:
Overnight, only glow issued from one small hole along the north
edge and another out-of-sight hole on the east side of the floor
of a deep pit in Halema`uma`u Crater floor. This morning, an
off-white plume is moving low and to the southwest. The most
recent sulfur dioxide emission rate measurement was 800
tonnes/day on December 1, still elevated above the 2003-2007
average of 140 tonnes/day; new measurements will not be possible
until moderate trade winds resume. Miniscule amounts of mostly
ash-sized tephra were deposited beneath the plume near the vent.
The summit tiltmeter network recorded the start of DI deflation
at 0400 hrs this morning. The GPS network, which is less
sensitive than the tiltmeter network, recorded about 1 cm of
contraction over the last 3 months. Seismic tremor levels
increased slightly during DI deflation but remained at low
values. As of the 4th of December,HVO reported that at the
summit, spattering continued from openings in the floor of a
deep pit in the floor of Halema`uma`u Crater floor. Sulfur
dioxide emission rates from the Halema`uma`u and east rift zone
vents remain elevated. From the east rift zone vent, lava flows
through tubes to the coast and is entering the ocean at several
locations west of Kalapana. As of the 20th of November, HVO
reported that a small collapse overnight enlarged a hole deep in
the Halema`uma`u Overlook vent cavity floor revealing an active
lava pond. Sulfur dioxide emission rates from the Halema`uma`u
and east rift zone vents remain elevated. Lava flows were active
on the coastal plain. Lava was also flowing through tubes to the
coast and entering the ocean at two general locations west of
Kalapana. A small collapse last night around 2300 hrs enlarged
one of the holes deep within the Halema`uma`u vent cavity
exposing a roiling, bubbling, and spattering lava pond surface;
the surface rises and falls slowly over the next 20 minutes,
remains fairly steady, and then starts an episodic rising and
falling sequence observed seven times before dawn's early light
washed out the view. Stronger glow was visible after 2300 hrs at
the Jaggar Museum Overlook. This morning, the dense white plume
rises into morning fog, but appears to moving southwest. The
most recent sulfur dioxide emission rate measurement was 700
tonnes/day on November 18th - still elevated above the 2003-2007
average of 140 tonnes/day. As of the 13th of November, HVO
reported that the sixth DI event in a week is nearing
completion. A few small holes deep in the Halema`uma`u Overlook
vent cavity floor continued to glow and produce spatter from a
lava pond surface below. Sulfur dioxide emission rates from the
Halema`uma`u and east rift zone vents remain elevated. Lava
flows are active on the coastal plain. Lava is also flowing
through tubes to the coast and entering the ocean at two
locations west of Kalapana. DI events often affect surface flow
activity on the flow field. Typically, surface flow activity
will decrease 12-24 hours after the start of deflation and
resume 12-24 hours after the start of inflation. The last five
DI events were of short duration and small amplitude and have
not produced many effects; the current one has a larger
amplitude and we might expect some, probably small, decreases in
activity today. Last 24 hours at Kilauea summit: The Overlook
vent webcam images again showed fluctuating glow and spattering
from a few small holes deep within the Halema`uma`u vent cavity.
This morning, the plume is rising about 600 m (2,000 ft) and
moving to the west. The most recent sulfur dioxide emission rate
measurement was 400 tonnes/day on November 9th, which is the
lowest value since early October but still elevated above the
2003-2007 average of 140 tonnes/day. As of the 4th of November,
HVO reported that lava began entering the ocean at a second
location, 700 m farther to the W, on 31 October. Thermal
anomalies detected in satellite images and visual observations
revealed active surface lava flows. Breakout lava flows were
located inland of the Waikpuanaha entry and also immediately W
of the County Public Viewing trail. Intermittent incandescence
was seen from the Pu'u 'O'o crater floor and an East wall vent.
The vent in Halema'uma'u crater continued to produce a diffuse
white plume that drifted SW. Incandescence originated from
occasionally spattering holes from a surface inside the vent
cavity. On 3 November, a collapse of the surface revealed a
circulating and spattering lava pond below. During 21-27 October
HVO reported that lava flowed SE from underneath Kilauea's
Thanksgiving Eve Breakout (TEB) and rootless shield complex
through a lava tube system, reaching the Waikupanaha ocean entry
on most days. Thermal anomalies detected in satellite images and
visual observations revealed active surface lava flows. For a
few days an active lava flow advanced on the coastal plain,
burning vegetation and pavement along the former Kalapana access
road. Intermittent incandescence was seen from the Pu'u ‘O'o
crater floor and an East wall vent. During 16 and 17 September,
two hybrid earthquakes were followed by 20-40 minutes of
sustained tremor. The plume turned briefly"dusty" after the
first event and incandescent tephra was ejected onto the rim
after the second event; both produced glassy spatter. As of the
18th of September, HVO reports that two more hybrid seismic
signals were recorded which produced increased amount of spatter
and glow was visible after dark from the Halema`uma`u Overlook
vent (summit). As of the 7th of August, a minor earthquake has
rattled the south flank of Kilauea volcano. The U.S. Geological
Survey says the 3.0-magnitude temblor struck last night about 8
miles southeast of the summit and about 6 miles below the
surface.
As of the 1st
of July, HVO reported that a sequence of rockfalls, some quite
large, within the Halema'uma'u vent at the summit of Kîlauea
Volcano began at 1:38 p.m. H.s.t on June 30, 2009. The initial
rockfall produced a seismic signal equivalent to a magnitude-2.4
earthquake and was felt at the Hawaiian Volcano Observatory
(HVO) and the adjacent Jaggar Museum. By 4:00 p.m., more than 30
such rim-collapse events had been recorded by the seismometers
with a few more occurring through today, July 1. Seismic tremor
amplitudes decreased by more than 50 percent. By 6 p.m., the
levels were at their lowest values since August 30, 2007.
Episodic tremor has now returned with 3 minute bursts of tremor
occurring every 15 minutes. As of the 15th of April, HVO reporte
that a magnitude-5.0 earthquake beneath the south flank of
Kilauea Volcano was recorded on Tuesday, April 14, at 12:44 p.m.
H.s.t. The earthquake was located about 12 km (8 miles)
southeast of Kilauea's summit and 44 km (27 miles)
south-southwest of Hilo at a depth of 10 km (6.2 miles). The
earthquake was felt over the entire Island of Hawai`i. The U.S.
Geological Survey received over 350 felt reports in the first 30
minutes after the earthquake. Eleven earthquakes with magnitudes
of 4 or greater, including three with magnitudes of 5 or more,
have occurred in this area, the central part of Kilauea's south
flank, at nearly the same depth (8-10 km or 5-6 miles) in the
last 25 years. These quakes are thought to be caused by
southward movement of the south flank in response to magmatic
pressure within the east rift zone. The earthquake caused no
apparent change to the current eruption of Kilauea. Monitoring
networks supported by HVO have not detected significant changes
in volcano activity. During 8-14 April, HVO reported that lava
flowed SE from underneath Kilauea's Thanksgiving Eve Breakout
(TEB) and rootless shield complex through a lava tube system,
reaching the Waikupanaha and Kupapa'u ocean entries. Occasional
explosions occurred from the Waikupanaha ocean entry. Surface
flows on the coastal plain or from the Prince lobe were seen or
detected by satellite imagery. The vent in Halema'uma'u crater
continued to produce a white plume occasionally tinged brown
that drifted mainly SW. incandescence was intermittently seen
from the vent. On 2 April, geologists found that the surface
lava flow feeding the Kupapa'u entry was 1 km (0.6 m) wide. As
of the 20th of March, HVO reported that the anticipated switch
to DI inflation occurred the day before in the evening. Lava
from east rift zone vents continues to flow through tubes to the
coast and is entering the ocean at two locations. Sulfur dioxide
emission rates from the Halema`uma`u and Pu`u `O`o vents remain
elevated. On 11 February, geologists found a new littoral cone,
on the edge of the bench, with a large crack running through it.
Spatter on the cone and the bench behind it resulted from lava
bubble bursts and steam jetting reported during the previous two
days. A second crack between the cone and the sea cliff was also
noted. The cracks suggested that the bench was slowly failing
and did not collapse as reported a few days prior. Occasional
incandescence originated from the Prince lobe, the flow that
feeds the Waha'ula ocean entry. Thermal anomalies suggesting
surface flows were noted on the coastal plain and on the pali.
The vent in Halema'uma'u crater continued to produce a
predominantly white plume that drifted mainly SW; the
incandescence was intermittently seen from the vent. Small
amounts of tephra, including Pele's hair and some spatter, were
routinely collected. Infrared images taken during an overflight
on 11 February revealed the development of a small spattering
cone over the conduit that hosted a lava pond the previous week.
Images taken on 14 February indicated that the conduit had
mostly crusted over; a small, puffing vent was visible. The
sulfur dioxide emission rate at the summit was 800 tonnes per
day on 12 February, and 500 tonnes on 13 February; the 2003-2007
average rate was 140 tonnes per day. As of the 15th of October,
HVO reported that Tuesday 14th of October at 12:26 and 4:07 pm,
the Halema`uma`u vent produced explosions; the earlier explosion
was initiated by a collapse of a thin piece of the vent rim; the
second erupted molten spatter deposited as cowpies with 100 m
(yards) of the vent and produced an eruption column that rose
about 2 km (6,500 ft) above the crater rim. Between explosions,
weak easterly winds moved the gas/steam plume to the west
resulting in intermittently poor air quality at the summit. Glow
from the Halema`uma`u vent overnight was variable and weak;
spatter from the 4:07 pm eruption ignited a sulfur deposit on
the crater wall to the west of the vent producing a blue flame
visible at night. Wednesday morning, weak winds are allowing the
plume to rise vertically into generally foggy/voggy conditions.
Sulfur dioxide emission rates remained elevated and variable.
The most recent average measurement was 1,200 tonnes/day on
October 10, compared to the 2003-2007 average rate of 140
tonnes/day. Moderate trade winds are needed for emission rate
measurements. Kilauea caldera network of tiltmeters recorded an
offset with the 4:07 pm explosion followed by accelerated
deflation that is slowing this morning. The GPS receiver
networks (less sensitive than tiltmeters) recorded no
significant contraction or extension.Previously the 13th of
october, HVO reported that early on the morning of Sunday 12
October (7:28 am), there was a significant explosive event at
Halema'uma'u crater. This new gas vent opened in Halema`uma`u
Crater at the summit of Kilauea Volcano. Since then, sulfur
dioxide (SO 2 ) emissions and the associated volcanic air
pollution (vog) have impacted air quality on Hawai`i Island and,
at times, throughout the entire state. Volcanic ash in the
Halema`uma`u gas plume also resulted in the closure of air space
above the crater. The explosive eruption did produce
significant tephra deposits, some of the pieces were fist- to
grapefruit-sized frothy lava. Most of the samples were glassy
lava bits with minor rock fragments and dust. Despite the fact
that the 10/12 07:28 hybrid seismic event was larger than
the 9/2 hybrid seismic event, the 10/12 deposit was
significantly smaller. As of the 10th of October, it has been
reported from the Hawaiian Volcano Observatory (HVO), that there
is an active lava flow on the pali east of Royal Gardens
subdivision; lava has resumed flow through tubes to the ocean;
Waikupanaha ocean entry is active. Sulfur dioxide emission rates
from both the Halema`uma`u and Pu`u `O`o vents remain high;
tephra production continues from the Halema`uma`u vent. Last 24
hours at Kilauea summit: Plume direction yesterday was to the
southwest and south. Glow from the Halema`uma`u vent overnight
was again episodic and bright but somewhat weaker than previous
nights; the lava pond is probably relatively high in the vent
but still well below the rim. As of the 6th of October, it has
been reported from the Hawaiian Volcano Observatory (HVO), that
for the DI tilt event that started last Thursday, the inflation,
expected to follow deflation, began at the summit just after
2000 hrs; anticipated inflation at Pu`u `O`o may have started
just before 0800 hrs this morning. Sulfur dioxide emission rates
from both the Halema`uma`u and Pu`u `O`o vents remain high;
tephra production continues from the Halema`uma`u vent. A
significantly reduced amount of lava, if any at all, flows
through tubes to the ocean. If inflation has started at Pu`u
`O`o, increased lava into the tubes, possible surface flow
activity, and resumption of the ocean entry are expected
sometime within the next 24 hours. As of the 8th of September,
it has been confirmed from the Hawaiian Volcano Observatory
(HVO), that for the first time since the new vent opened in
Halema'uma'u Crater on March 19, HVO scientists in a helicopter
hovering over the crater during the day 5th of september were
able to see the surface of a sloshing 50 m (160 ft) diameter
lava lake about 100 m (330 ft) below the vent rim. HVO
scientists have speculated that a lava pond existed a few
hundred meters below the vent, but have not been able to get
visual confirmation until this morning. A second viewing early
this afternoon revealed a roiling pond with multiple bursting
bubbles changing into a central upwelling circulation pattern.
The lake level dropped slightly before the cycle restarted. This
behavior has been witnessed before, most recently in Pu'u 'O'o
vents and the July 21 lava ponds on Kilauea's east rift zone,
and is known as "gas pistoning." One model explains pistoning as
small gas bubbles coalescing into larger bubbles beneath a crust
on a lava pond, rising to the surface, and then bursting. The
released pulse of hot gas carries rock dust from the collapsing
vent walls, bits of the lava lake crust, and small amounts of
spatter. Previously a small explosive eruption at 0737 hours on
Aug. 27th was confirmed this morning. At the east rift eruption
site, Pu`u `O`o cone continued to produce high amounts of sulfur
dioxide gas; lava flows through tubes to the ocean. The
signigicative explosion at 0737 hours noted in yesterday's
update (8/27) was actually a very small explosive eruption, the
fifth in 2008. This morning's collection yielded volcanic glass
bits up to several centimetres across within a deposit that was
dominantly rock fragments up to 5 cm (2 inches) across. The
tephra was ejected hot and burned holes in a tarp used for
collection near the overlook. during 20-26 August, lava flowed
SE through a lava tube system from underneath Kilauea's
Thanksgiving Eve Breakout (TEB) and rootless shield complex to
the Waikupanaha ocean entry. From
HVO -
Near real-time web cam Pu'u'O'o.
Halemaumau
webcam
***********************************************************************************************************
U.S.A.
- Mauna Loa ( Hawaii)
January
12th, 2010
As of the
11th of January, the Hawaiian Volcano Observatory (HVO) has
reported there has been no recent significant change in line
length across the summit or the flanks of Mauna Loa as measured
by GPS receivers on opposite sides of the volcano. Tiltmeters
have recorded no significant changes other than abrupt offsets
that are related to instrumental issues, severe weather, or
significant earthquakes. Sensors within a fissure in
Moku`aweoweo crater floor reported gas concentrations within
normal values; fumarole temperatures continued to slowly
decrease. Line lengths have been increasing at a slightly faster
rate since September, 2008,due mostly to slippage on basalt
faults beneath Mauna Loa's east flank and not to an increase in
magma supply to the volcano. Tiltmeters have recorded no
significant changes other than abrupt offsets that are related
to instrumental issues. Diurnal tilt, or the tilting due to
daily heating and cooling of the ground, was diminished by
snowfall starting Christmas Eve, 2008. Sensors within a crack in
Moku`aweoweo crater floor continued to record background gas
concentrations and temperatures. Since the beginning of January,
2005, HVO analysts have rarely located more than 10 earthquakes
per week beneath Mauna Loa summit. Each week, 1-5 earthquakes
are also located beneath the Kealakekua area of west Mauna Loa.
These levels are typical of the past several years. The Kao`iki
seismic zone between Mauna Loa and Kilauea volcano summits
remained active with an average of about 10-40 earthquakes per
week; these numbers may reflect increased seismic activity
nearer Kilauea summit rather than increased Kao`iki activity.
***********************************************************************************************************
USA - Cleveland volcano (Alaska)
October 9th, 2009
As of the
9th of October, the Alaska Volcano Observatory (AVO) reported
that no additional eruptive activity has been observed at
Cleveland since the brief eruption at approximately 2330 hrs
AKDT October 2nd (0730 hrs UTC October 3rd). Satellite and web
camera views of the volcano are currently obscured by clouds.
The lack of a real-time seismic network at Cleveland means that
AVO is unable to track local earthquake activity related to
volcanic unrest. Short-lived explosions with ash plumes that
could exceed 20,000 ft above sea level can occur without warning
and may go undetected on satellite imagery. Alaska Volcano
Observatory (AVO). The
beautifully
symmetrical Mt. Cleveland stratovolcano is situated at the
western end of the uninhabited, dumbbell-shaped Chuginadak
Island. It lies SE across Carlisle Pass strait from Carlisle
volcano and NE across Chuginadak Pass strait from Herbert
volcano. Cleveland is joined to the rest of Chuginadak Island by
a low isthmus. The 1730-m-high Mt. Cleveland is the highest of
the Islands of the Four Mountains group and is one of the most
active of the Aleutian Islands. The native name for Mt.
Cleveland, Chuginadak, refers to the Aleut goddess of fire, who
was thought to reside on the volcano. Numerous large lava flows
descend the steep-sided flanks of the volcano. It is possible
that some 18th-to-19th century eruptions attributed to Carlisle
should be ascribed to Cleveland (Miller et al., 1998). In 1944
Cleveland produced the only known fatality from an Aleutian
eruption. Recent eruptions from Mt. Cleveland have been
characterized by short-lived explosive ash emissions, at times
accompanied by lava fountaining and lava flows down the flanks.
************************************************************************************************************************
U.S.A.
- Redoubt volcano (Alaska)
April
8th, 2010
As of the
7th of March, the shallow, small earthquakes at Redoubt Volcano
continued at about the same rate as yesterday. Satellite images
from yesterday evening show a steam plume extending from the
summit. Webcam views of Redoubt continue to be obscured by
clouds.As of the 5th of April, AVO raised the Aviation Color
Code to YELLOW and the Volcano Alert Level to ADVISORY at
Redoubt volcano this morning. A series of small repetitive
earthquakes began at 01:44 AKDT (0944 UTC) this today in the
vicinity of the volcano's summit. Activity is continuing this
afternoon. These earthquakes may be precursory to renewed
eruptive activity at the volcano and increased instability of
the lava dome. Whether this will result in explosive activity or
failure of the lava dome is unknown at this time. However, there
is a heightened possibility of volcanic activity that would
produce a volcanic ash cloud, pyroclastic avalanches, and lahars
and flooding down the Drift River.As of the 6th of January, the
Alaska Volcano Observatory (AVO) reported that seismic activity
at Redoubt Volcano remains low. Web camera and satellite views
of the volcano have been obscured by clouds and snow. There have
been no reports or indications today of unusual activity at the
volcano. The Aviation Colour Code remains YELLOW and the Volcano
Alert Level remains ADVISORY. AVO is continuing to evaluate
information to interpret this week's uptick in seismicity and
gas output. One explanation involves input of new magma or
remobilisation of existing magma within volcano's shallow
plumbing system. This process appears to have ceased or paused.
It remains possible that activity could reappear, intensify and
lead to additional eruptive activity. We would expect a sharp
increase in seismicity and other marked changes prior to such
activity. AVO will continue to issue daily status reports as
long as the Aviation Colour Code and Alert Level are elevated.
As of the 28th of August 2009, AVO reported that the code status
has been lowered for Aviation to Colour Code Green and Volcano
Alert at Code Normal at 18:44 GMT on 29 September 2009. Over the
past several months, seismic activity, volcanic gas output,
ground deformation, lava dome temperatures, and outward signs of
lava dome instability at Redoubt Volcano have been declining.
The volcano appears to have returned to its normal background
condition and for now poses no immediate threat of eruptive
activity. Accordingly, AVO is lowering the Aviation Color Code
to GREEN and the Volcano Alert Code to NORMAL. The AVO notes
that the Redoubt lava dome has reached a volume of approximately
70 million cubic metres, and that lava domes on steep slopes are
‘typically unstable'. However, given that 60 days have passed
since the dome ceased to grow, ‘AVO believes the possibility for
dome collapse is small and declining toward a background level
of danger typical of many active stratovolcanoes with steep
unstable rock slopes'. Local hazards remain, associated with the
hot lava dome: gas emission, abundant steaming, rockfalls, but
these do not pose a significant hazard beyond the summit area of
the volcano. On 12 June, the lava dome was an estimated 1 km
long, 460 m wide, and 200 m high. The Volcanic Alert Level
remained at Watch and the Aviation Color Code remained at
Orange.On 28th of May. a M3.7 earthquake occured on the Alaska
Peninsula at approximately 03:11 shows prominently on the
Redoubt webicorder records. Again, this seismic event is not
related to activity at Redoubt. AVO reported that during 20-26
May seismicity from Redoubt remained above background levels and
growth of the lava dome in the summit crater continued.
Steam-and-gas emissions from the lava dome were seen on the web
camera during 20-21 and 26 May; clouds obscured the view during
the rest of the reporting period. Occasional rockfalls
originating from unstable slopes of the lava dome possibly
produced minor ash clouds in the vicinity of the summit,
although no ash was detected by satellite or radar. As of the
20th of May, AVO reported that during 13-19 May seismicity from
Redoubt had decreased from levels detected during 2-7 May, but
remained above background levels. Rock avalanche events,
discrete earthquakes, and minor volcanic tremor were evident in
seismic data. Growth of the lava dome in the summit crater
continued and vigorous steam emissions from the margins of the
lava dome were seen on the web camera. Occasional rockfalls
originating from unstable slopes of the lava dome produced minor
ash clouds in the vicinity of the summit. Occasional
incandescence was observed in nightime images from the web
camera. On 15 May, the volume of the dome was an estimated 30-60
million cubic meters. During an overflight on 16 May, scientists
observed a turquoise lake along the S margin of the dome, and a
hot, vigorous, and persistent fumarole on the W wall of the
upper gorge. The Volcanic Alert Level remained at Watch and the
Aviation Color Code remained at Orange. During 29 April-5 May,
AVO reported that elevated seismicity from Redoubt and a
persistent thermal anomaly over the summit lava dome detected on
satellite imagery were consistent with continued lava-dome
growth. Changes in the size and shape of the dome confirmed
growth; the volume of the dome was an estimated 25-30 million
cubic meters. Occasional small rock avalanches originating from
the N side of the lava dome produced minor low-level ash
emissions. As of the 3rd of May, the Alaska Volcano Observatory
(AVO) reported that eruption of Redoubt volcano continued.
seismic activity has increased in the last 24 hours. Minor
emissions of ash have also been visible in webcam views during
this time period. A vigorous steam plume, rising to altitudes up
to 18,000' above sea level, has been visible in webcam images
throughout the afternoon of 3rd of May. Currently, this plume
contains small amounts of ash based on web camera views,
satelite data, and a pilot report. Seismic activity has also
increased in the past 24 hours. previous notable informations :
ongoing lava dome growth kept seismicity at Redoubt remained
elevated during 15-21 April, and vigorous steam-and-gas plumes
(possibly with occasional small amounts of ash) rose to
altitudes below 4.6 km a.s.l. Satellite imagery revealed thermal
anomalies at the summit and drifting SO2 plumes. The lava dome
size was estimated on 16 Aril to be 500 x 700 m across and at
least 50 m thick. Seismic and satellite data over the past day
indicate continued lava dome growth. The volcano was not visible
in web camera views during the night. A low-level steam and gas
plume that may contain small amounts of ash is likely present.
Based on seismic data and satellite imagery, AVO reported that
Redoubt's lava dome continued to grow during 8-14 April. As of
the 10th of April, A small steam plume with possible traces of
ash has been visible in satellite and partially-obscured webcam
images today. The plume is currently extending to the northeast
of the volcano at low altitudes. Additional significant
explosive events with accompanying ash clouds, ash fall, and
mudflows are possible and can occur with little or no warning.
AVO will maintain 24/7 operations in order to quickly detect
renewed significant explosive activity and other hazardous
phenomena. Seismic and satellite data over the past day indicate
continued lava dome growth. A satellite image from yesterday
afternoon showed a continuous sulfur dioxide gas plume extending
for more than 600 miles from volcano. As of the 3rd of April,
AVO reported that the eruption continued, but the intensity of
ash-production has decreased. The current alert level at Redoubt
is WATCH and aviation color code is ORANGE. The small, shallow
repeating volcanic earthquakes have diminished. A few occasional
larger events are still being observed. These earthquakes are
most prominent on station REF. As the 2nd of April, AVO reported
that the volcano continues to emit a plume of gas, steam and
variable amounts of ash to low elevations. Winds are blowing the
plume E to ESE. Weak volcanic tremor is ongoing, punctuated by
small, discrete earthquakes. As of the 30th of March (11:56AM -
AKDT), AVO reported that Over the past twelve hours, ash
emissions at Redoubt Volcano have become more frequent, but
lower in altitude than during the highly explosive events of the
past week. A continuous ash plume has been observed in web
camera, satellite and radar images, and by pilots. These plumes
vary in their intensity and have generally been at low altitude
(less than 20,000 feet above sea level). Occasional, short lived
events have produced ash clouds that rise as high as 27,000 feet
above sea level. Ash fall from these events is currently not
likely to reach population centers in the Cook Inlet. In the
evening, Seismicity continued to show small, discrete events.
Observers on an AVO gas flight reported ash falling from the
plume 20-25 miles from the vent. Winds at that altitude are
heading NE from the volcano. A regional earthquake south of
Kodiak was visible on the webicorders at 19:28. As of the 27th
of March, AVO reported that three more explosions occured on
Friday. The first eruption at 17:35 AKDT (01:35 GMT) produced an
eruption cloud to 40000 feet (12200 metres) above sea level; the
second eruption at 19:25 AKDT (03:25 GMT) sent up a plume to
51000 feet (15500 metres); and the third, beginning at 23:20
AKDT (07:20 GMT), produced a cloud that has reached 40000 feet
(12200 metres). Due to important ashfall the Hut webcam has been
covered since 18:00 local time and no new images were
available.. As of the 23rd of March, AVO reported that the last
explosive event occurred during the night (March 23) at 7:41 pm
(AKDT) and lasted for roughly seventeen minutes. The top of the
ash cloud was estimated to have reached at least 50,000 ft above
sea level based on National Weather Service radar. Winds in the
vicinity of the volcano carried the ash cloud primarily to the
west and north. Pyroclastic flows were visible traveling down
the volcano's north flank in web camera images. Last night's
explosive event was the sixth thus far since explosive activity
began Sunday. The day before, AVO staff visited the area around
Redoubt by helicopter to assess conditions and repair equipment
damaged by Sunday night's eruptions. They fixed the telemetry
link at AVO's observation hut, which is once again transmitting
images from the web camera and data from a GPS and two seismic
instruments. Clouds obscured the summit, but observers reported
very large lahar and flood deposits in the Drift River Valley
that likely occurred during and/or following the first five
explosions. These flows, which contained ice, water, mud, and
other debris, inundated the Drift River Valley and traveled more
than 35 km, reaching Cook Inlet. In the middle to upper Drift
River Valley, high-water marks reached 6-8 meters above the
valley floor. At the AVO hut (roughly 7 miles NNW of the
summit), a 6-cm thick fall deposit was observed.As of 2:00AM
March 23, 2009, AVO has recorded FOUR large explosions at
Redoubt volcano at the following times: March 22 10:38PM; March
22 11:02PM; March 23 12:14AM; March 23 01:39AM. On Sunday
morning, 40 to 50 earthquakes were being recorded every hour.
The largest eruption sending a plume of smoke some 50,000 feet
above sea level The National Weather Service has issued an
Ashfall. The first Mt. Redoubt began at approximately 22:38
AKDT, March 22, 2009 (0638 UTC). AVO was raising immediatly the
aviation color code to Red and the alert level to Warning.
Initial height of the eruption cloud is estimated at less than
20,000 ft above sea level at present. Previously, as of the 19th
of March, AVO reported that Mount Redoubt was been going through
some interesting seismic evolutions over the past 24 hours. From
around 00:00 to around 08:00 GMT on 20 March (around 16:00-00:00
on 19 March, local time) there was a period of marked volcanic
tremor. The amplitude of the tremor diminished subsequently, but
a pattern of small discrete quakes (around 1-2 per hour)
interspersed with occasional larger seismic events continued,
with the smaller quakes increasing in frequency and amplitude
from around 10:00 local time A special bulletin from AVO
reported that seismic activity at Mount Redoubt increased at
about 1:05 AKDT Sunday afternoon (March 15, 2009) and
approximately 4 hours of continuous volcanic tremor ensued. The
onset of the tremor was associated with a small explosion that
produced a plume of gas and ash that rose to about 15,000 feet
above sea level and deposited a trace amount of ash over the
summit-crater floor and down the south flank of the volcano to
about 3,000 feet. AVO responded to this increase in activity by
raising the color code and alert level to ORANGE/WATCH at 2:50
PM AKDT. At this time it does not appear that the increase in
activity heralds a significant eruption in the short term, but
conditions may evolve rapidly. An AVO overflight Sunday
witnessed activity from 11:30 AM until about 3:00 PM and was
able to document ash emission from a new vent, just south of the
1990 lava dome and west of the prominent ice collapse feature
near the north edge of the summit crater. Although ash emission
was short lived, it represents the first documented ash fall
during the current episode of unrest at Mount Redoubt. About
twenty minutes after the initial steam and ash burst, a
sediment-laden flow occurred from a small area in the ice at
about 7000 feet on upper Drift glacier. This flow descended
about 1500 feet and produced a distinctive seismic signature
seen across the Redoubt network. On 25 February, a small mud
flow originating from a melt hole in the Drift Glacier traveled
several hundred meters. Satellite images revealed that the next
day another mudflow traveled several kilometers and covered a
large portion of the Drift Glacier. Web camera views and
satellite imagery showed no unusual activity; steam plumes
within the summit crater were seen on the web camera on 26 and 1
March. As of the 27th of February, the Alaska Volcano
Observatory (AVO), reported that at unrest at Redoubt Volcano
continues. Beginning yesterday afternoon at 1537 hrs AKST,
tremor amplitude increased sharply and remained elevated for
approximately one hour. At 1614 hrs AKST, the tremor amplitude
briefly matched the highest amplitude seen during the current
episode of unrest. This tremor was strong enough to be recorded
on all seismic stations on Redoubt Volcano as well as many
stations surrounding Cook Inlet. Since that time, tremor
amplitude has decreased significantly. Last night around 2240
hrs AKST, the number of discrete earthquakes increased and
remained elevated until about 0255 hrs AKST today. Preliminary
analysis of these earthquakes indicate they are occurring at
shallow depth (1 to 3 km) below the summit crater of Redoubt.
Since that time, discrete events are continuing at a lower rate,
and tremor levels remain low. These variations in the character
of seismic activity indicate that conditions have changed at
shallow depths beneath the volcano. AVO is currently analyzing
this seismic activity and will issue further information as it
becomes available. An observation flight to the volcano is
currently underway. Winds are too high at the volcano to perform
gas measurements today. A small steam plume is visible in clear
Hut Cam images today. AVO continues to monitor Redoubt Volcano
closely, and the observatory is staffed 24 hours a day. A burst
of volcanic tremor occurred just after 3:00 PM in the afternoon
5th of February lasting for about 30 minutes and is continuing
at a sustained but lower level. This did not result in any
eruptive activity and no ash emission has occurred. Following
bursts of volcanic tremor during the afternoon , background
tremor has remained elevated relative to the past several days.
AVO continues to monitor the volcano 24/7. As of the 1st of
February AVO reported that unrest at Redoubt Volcano continues.
Seismicity has remained relatively constant over the last 24
hours and is still well above background. A vapor plume is
intermittently visible in the AVO web camera. It appears to rise
no higher than the volcano's summit. An observation and
gas-measurement flight to the volcano yesterday noted continued
vigorous fumarolic activity and runoff of muddy water down the
north flank of the volcano. Volcanic gas was detected; data
analysis is ongoing to compare these measurements with
previously measured gas output. As of the 30th of January, AVO
reported that seismicity levels have increased since yesterday
evening and have also risen markedly over the last hour. Pilot
reports, clear AVO webcam views, and satellite and radar views
confirm that Redoubt Volcano has not yet erupted at the time of
this report. Redoubt remains at Aviation Color Code ORANGE and
Volcano Alert Level WATCH. As of the 25th of January, AVO
previously reported that over the past 48 hours, seismic
activity at Redoubt Volcano has increased markedly. This has
taken the form of periodic tremor bursts that are most visible
on the two seismic stations closest to the summit. Beginning at
00:58 AKT (9:58 UTC) this morning, tremor became sustained and
its amplitude increased markedly. AVO raised the Aviation Color
Code to ORANGE and the Alert Level to WATCH in the morning at
2:09 AKT (11:09 UTC). This activity could be precursory to an
eruption, perhaps within hours to days. A further increase in
seismicity is expected to accompany an eruption. Information
Statement Unrest at Redoubt Volcano continues. AVO conducted an
overflight of the volcano in the afternoon of 25th of January,
and observations confirmed that an eruption has not occurred
yet. Increased steaming through previously observed sources in
the snow and ice cover were seen and sulfur gas emissions were
noted. There was no significant disruption of the glacial ice,
nor any apparent increased water discharge down the Drift River.
Seismicity began to decline at about 05:30 AST (14:30 UTC) on
the morning, but remained elevated. AVO raised the Aviation
Color Code to YELLOW and the Volcano Alert Level to ADVISORY on
November 5, 2008, in response to increased emissions of SO2,
H2S, and CO2; melting of snow and ice near the volcano's summit;
and a subtle increase in seismicity. These observations
reflected a change in the volcano's hydrothermal system,
possibly associated with an influx of new magma beneath the
volcano. It is also possible that the change was related to the
development of a new pathway of heated fluids rising from magma
intruded during the 1989-90 eruption. From Miller et al (1998):
"Redoubt Volcano is a steep-sided cone about 10 km in diameter
at its base and with a volume of 30-35 cubic kilometers. The
volcano is composed of intercalated pyroclastic deposits and
lava flows and rests on Mesozoic granitic rocks of the
Alaska-Aleutian Range batholith (Till and others, 1993; 1994).
It has been moderately dissected by the action of numerous
alpine glaciers. A 1.8-km-wide, ice-filled summit crater is
breached on the north side by a northward-flowing glacier,
informally known as the Drift Glacier, which spreads into a
piedmont lobe in the upper Drift River Valley. The most recently
active vent is located on the north side of the crater at the
head of the Drift glacier. Holocene lahar deposits in the
Crescent River and Drift River valleys extend downstream as far
as Cook Inlet."
Live webcam
USA - Mount Cleveland volcano (Aleutian islands)
October
2nd, 2009
As of the
2nd of october, AVO reported that satellite data indicate that
Cleveland volcano erupted briefly on 02 October in the morning
at ~0730 UTC (2330 AKDT) producing a small, detached ash cloud
that drifted northeast of the volcano at maximum altitudes of
15,000' to 20,000' (4.5 – 6.1 km) . AVO increased the aviation
color code to Orange, and the volcano alert level to Watch at
02:29 AKDT (10:29 UTC) this morning. Satellite views until about
6:45 AKDT (14:45 UTC) show that the ash cloud drifted northeast
about 600 km (373 mi) and dispersed over the Bering Sea. While
no more events have been detected this morning, further eruptive
activity is possible. Previously, as of the 26th of June, the
Washington Volcano Ash Advisory Center (WVAAC) reported that the
Alaska Volcano Observatory (AVO) reported small eruption at
1915Z to 15,000 ft. with mostly steam and little ash. Dark
visible ash can be seen in visible and in infrared and
multi-spectral imagery and visible ash is now in the Washington
VAAC area. In a further update, AVO reported a small eruption at
1915Z to 25,000 ft. with mostly steam and little ash. Eruption
can be seen in imagery and visible ash is now in the Washington
VAAC area. Forecast updated with currently VAFTAD. Visible ash
to 25,000 moving S at 69 mph. Beautifully symmetrical Mt.
Cleveland stratovolcano is situated at the western end of the
uninhabited, dumbbell-shaped Chuginadak Island. It lies SE
across Carlisle Pass strait from Carlisle volcano and NE across
Chuginadak Pass strait from Herbert volcano. Cleveland is joined
to the rest of Chuginadak Island by a low isthmus. The
1730-m-high Mt. Cleveland is the highest of the Islands of the
Four Mountains group and is one of the most active of the
Aleutian Islands.
U.S.A.
Veniaminoff volcano (Alaska)
May
28th, 2009
On 26 May,
AVO reported that seismicity from Veniaminof had decreased
during the previous week. The Volcanic Alert Level was lowered
to Normal and the Aviation Color Code was lowered to Green. As
of the 8th of May, AVO reported that seismic activity began to
increase significantly above normal background levels on the
morning of May 6 at Veniaminof Volcano. This increase caused AVO
to raise the Aviation Color Code to YELLOW and the Volcano Alert
Level to ADVISORY on the afternoon of May 7. Seismicity
continues at an elevated rate with numerous small magnitude
earthquakes being registered across the entire seismic network.
Visual observations from residents of Perryville over the past
several days indicate no change in the typical steaming from the
summit caldera cone that has been the site of activity over
recent years. Satellite images show no evidence of increased
heat flow or ash emissions. Given the elevated seismicity, it is
possible that low-level ash emissions could occur with little or
no additional warning. Ash emissions from typical eruptions of
Veniaminof are relatively minor, and usually do not rise much
higher than 15,000 ft above sea level. These ash plumes can
extend for tens of miles and could be hazardous to aircraft in
the vicinity of the volcano. Ash fall is typically confined to
the summit caldera and the upper flanks of the volcano. Mount
Veniaminof is a broad central mountain, 35 km wide at the base,
truncated by a spectacular steep-walled summit caldera 8x11 km
in diameter. The caldera is filled by an ice field that ranges
in elevation from approximately 1750 to 2000 m; ice obscures the
south rim of the caldera and covers 220 square km of the south
flank of the volcano. Alpine glaciers descend from the caldera
through gaps on the west and north sides of the rim and other
alpine glaciers occupy valleys on the north-, east-, and
west-facing slopes of the mountain. In the western part of the
caldera, an active intracaldera cone with a small summit crater
has an elevation of 2156 m, approximately 330 m above the
surrounding ice field. The rim of a larger but more subdued
intracaldera cone protrudes just above the ice surface in the
northern part of the caldera; based on limited exposure and
physiographic features, it may have a summit crater as much as
2.5 km in diameter. (GVN)
U.S.A.
- Mount St.Helens
May
3rd, 2009
No recent
significative report has been published from the CVO. The
volcano remains quiet since the year 2007 when an explosive
event occured. The pause in lava dome growth continues. This
pause, which began in late January 2008, was recognized by
absence of measurable growth among successive fixed-camera
images, nearly quiescent seismicity, and the absence of tilt
signals that might characterize extrusion of lava from the
conduit.
Previous
activity : as of the 9th of March 2007, the Cascades Volcano
Observatory (CVO) was reported that on 8th of March a small
explosive event at Mt. St. Helens volcano began at approximately
5:25 p.m. PST one hour after a magnitude 2.0 volcanic earthquake
was registered under the volcano. Pilot reports indicate that
the resulting steam-and-ash plume reached an altitude of about
36,000 feet above sea level within a few minutes and drifted
downwind to the east-northeast. The principal event lasted about
30 minutes with intensity gradually declining throughout. The
USGS Cascades Volcano Observatory lost radio signals from three
monitoring stations in the crater soon after the event started.
The cause of the outage won’t be known until scientists can
visit the crater tomorrow to assess the situation, weather
permitting. The event followed a few hours of slightly increased
earthquake activity that was noted but not interpreted as
precursory activity. The main part of the eruption lasted 30
minutes. Three monitoring stations in the crater have stopped
operating, and will be checked by scientists when conditions
permit. There were no other indications of an imminent change in
activity. During 21-26 October, the new lava dome inside the
emerging dome of St Helens continued to grow, and seismicity
remained at low levels compared to early in the unrest.
Geological and thermal-imaging observations on 20 October
confirmed that both the area of uplift, and the new lava
extrusion increased in size noticeably since last seen on 14
October. In addition, the area of uplift and intense deformation
continued to move southward and was nearing the crater wall.
About 0.3 m of new snow with a light dusting of ash covered much
of the uplift, except for the new lava extrusion, which was
steaming heavily. The new lava extrusion, which occupies the
western part of the uplift, was about 275 m long by 75 m wide,
70 m high, and had a volume of almost 1.5 million cubic meters.
Its maximum temperature was about 600 degrees C. Low levels of
carbon dioxide, sulfur dioxide, and hydrogen sulfide were
recorded on the 20th, an observation which did not rule out the
continued rise of magma from depth. On 21 October a new
protrusion had a maximum temperature of about 650 degrees C. As
of the 11th of October, CVO reported that earthquakes continue
to occur at a rate of about 1 per minute, but most have
magnitudes of 1.0 or less. With the improving weather, a gas
measuring flight is planned within the next two days. Additional
analysis of lidar and photographs of the intensely uplifting
area on the south side of the lava dome suggests that the total
volume change represented by the deformation between late
September and October 6 is about 16 million cubic meters (21
million cubic yards). The average rate of change is about 2
million cubic meters per day (2.6 million cubic yards per day).
If this figure represents the rate of intrusion of magma into
shallow levels of the dome and(or) underlying crater floor, it
is an intrusion rate about twice that measured during
dome-building eruptions at Mount St. Helens in the 1980s.
Cartographers with the USGS office in Denver are working to
develop precise volume change estimates for the uplifted area
from stereo airphotos acquired between 1 and 5 October. As a
result of the intense unrest of the past 17 days, we infer that
magma is at a very shallow level. During times of unrest, Mt.
St. Helens and similar volcanoes elsewhere typically go through
episodic changes in level of unrest over periods of days to
weeks, or even months. Such changes are in part driven by
variations in the rate of magma movement. CVO expects
fluctuations in the level of unrest to continue during coming
days. Escalation in the degree of unrest and perhaps an eruption
could occur suddenly or with very little warning. There may be
little time to raise the alert level before a hazardous event
occurs. Therefore, CVO continues to monitor the situation
closely and will issue additional updates and changes in alert
level as warranted. As of the 8th of October, the Cascades
Volcano Observatory (CVO) reported that part of the lava dome in
Mt. St. Helens' crater has risen 50 to 100 feet since Tuesday
while earthquake activity remained lower than previous days.
This indicates magma is moving upward without much resistance.
The south side of the dome has been rising for the past week and
has uplifted 250 ft. A new steam vent opened overnight of
6th-7th October, and joined the two that have been present for
several days. Steaming from the vents generated a cloud rising
above the south side of the lava dome. October 6th update :
Following yesterday morning’s steam-and-ash eruption, seismicity
dropped to a low level and has remained low. Low-level tremor
observed following the eruption is also gradually declining.
Lack of earthquake and rockfall signals suggest that deformation
of the uplift area on the south side of the 1980-86 lava dome
has slowed. Brief visual observations this morning from
Coldwater Visitor Center showed weak steam emissions from the
crater. We infer that the vigorous unrest of the past few days
has lessened and that the probability of an imminent eruption
that would endanger life and property is significantly less than
at any time since Saturday, October 2, when the alert level was
raised to Volcano Alert (Level 3). Therefore, we are lowering
the alert level to Volcano Advisory (Alert Level 2).New steam
release began at 9:40 am PDT yesterday, October 4, 2003,
generating a steam and ash/dust plume that rose above the summit
(to about 10,000 to 11,000 feet altitude) and was carried slowly
to the NE by very gentle winds. Steam releases continued at a
lower rate after the initial release, but after 15-20 muntes the
activity ceased. More dust/ash was released than on October 1,
and an ashfall advisory is in effect until 1 pm PDT for the
southern Washington Cascades. Seismicity continued without
interruption through the steam release. As of 3rd of October CVO
reported at 2 pm , CVO increased the alert level to Volcano
Alert due to a change in the character of seismic signals (50
minute long tremor) that occurred immediately after a steam
emission at 1216, recognition of ongoing uplift of the crater
floor, and reports of sulfur gas odor. In addition, CVO believes
that there is a significantly increased probability that
gas-rich magma is moving toward the surface. After another
period of tremor starting 4th of October at 0257 AM seismicity
returned to discrete earthquakes. Seismic activity decreased
gradually until about 2:00 P.M. then increased again, reaching
levels comparable to those prior to steam and ash eruptions. M3
earthquakes are occurring at a rate of about one every 5
minutes. All earthquake locations remain shallow. Yesterday’s
gas sensing flights detected significant concentrations of
carbon dioxide north and west of the dome. No significant levels
of sulfur gasses were detected. Hydrogen sulfide (H2S)odors
detected by helicopter crews are attributed to steam emissions.
These low levels of hydrogen sulfide are likely the result of
boiling of the hydrothermal system. Results from GPS
measurements indicate no significant deformation of the outer
flanks of the volcano. However, visual observations and
photographic analysis show large-scale uplift (10’s of meters)
of part of the glacier and a nearby segment of the south flank
of the lava dome. This suggests rise of magma to shallow levels.
Additional steam and ash eruptions could occur at any time.
There is also an increased probability of larger magnitude and
more ash-rich eruptions. Today field crews took additional
thermal images of the dome and crater and conducted gas sensing,
infrared and geologic observation flights. Deformation crews
retrieved data from GPS instruments and lowered a new GPS
station from a helicopter onto the dome. In addition, two
telemetered microphones are now operating to detect explosions.
Mount St. Helens erupted on 1st of October at 12:03pm PDT. The
activity continued for about 24 minutes, creating a steam and
dust plume that reached about 10,000 feet elevation and drifted
SSW toward Portland, OR and the Pacific coast. Steam vented from
a location at the southern edge of the dome where the dome edge
is covered by glacial ice and debris from the southern crater
wall. On Thursday afternoon N-S linear cracks were observed in
the glacier ice there, implying a slight uplift beneath the ice.
Video images of the eruption showed steam, some possibly
superheated, venting from a limited area and carrying blocks and
fines upward into a mostly-white steam plume.
Mt.St. Helens Live Cam
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Pu'u' O'o cone ( Kilauea ) - HVO -
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ITALY -
Etna volcano ( Sicily)
April 9th,
2009
As of the
8th of April INGV reported that a series of earthquakes occured
on April 2-3 along a fault near the north flank of the volcano -
175 earthquakes in all producing some impressive results. Boris
Behncke has noted increased rumblings at Etna since. This has
culminated in explosion and ash on April 7-8. Most of the ash
appears to be made from merely crushed rock of previous eruption
- accidental material rather than new juvenile magma, but all of
this suggests that Etna could be headed for a new eruptive
period. There has also been an increase in the gas emissions
from the volcano. Last previous information :as of the 20th of
December 2009, from John Seach reported that a swarm of
earthquakes occurred at Mt. Etna volcano on the 19th of
December. More than 30 earthquakes occurred in the swarm, with
the largest being magnitude 4.6. The swarm was located under the
northwest side of the volcano. Previously INGV reported that on
6 November 2009 deep explosive activity resumed at the SE
Crater. The Istituto Nazionale di Geofisica e Vulcanologia
monitoring web cameras detected pulsating red glowing from the
eastern base of the SE Crater, produced from a vent within the
depression that cuts its eastern flank. Explosive activity is
quite deep and visible as red glows only at night, and no ejecta
have been found on the snow that covers the summit of the
volcano. This activity is still going on as on today, 10
November 2009. As of the 26th of July, the INGV-CT reported that
in a visit on the morning of the 23rd of July, of the summit
craters, North Is, Bocca Nuova and Voragine with Pietro
Vinciguerra Alessandro Alaimo. The wind today was rather strong
breath on the tops compared to yesterday and pushes the gas
emissions letting appear in the interior of the craters. They
did not perceive any explosive activity in North Is and Bocca
Nuova. The Northern crater East emits only puffed out gas. New
cracks appeared on the edges of the crater and others present
before crumbled at the bottom of the crater. As of the 3rd of
June 2009, INGV-CT reported that during 25-31 May the
NW-SE-trending fissure E of the Etna summit craters continued
(since 13 May 2008) to produce active lava flows to the N of the
SE end of the fissure, along the W wall of the Valle del Bove.
At least three lava flows were active. Elsewhere on the volcano,
activity was restricted to degassing from the Northeast Crater,
from the NW and SE Bocca Nuova vents, from the E flank of the
Southeast Crater, and along summit fumarolic fields. The
activity was observed directly and by utilizing surveillance
cameras in Milo (about 11 km ESE). As of the 30th of April, the
INGV-CT reported that two new earth tremors of a magnitude of
3.0 on the Richter scale occurred today in Sicily the first this
night with the Agrigento and the second closer to Mt. Etna at
1142 hrs (local time) with 13 kilometres of Patti to a depth of
1 kilometre. As of the 26th of March, the INGV-CT reported that
after a week of Strombolian activity and ash emission from the
top of Etna's 2008 eruptive fissure, activity from the summit
craters during 16-22 March consisted of degassing from the
Northeast Crater, the NW Bocca Nuova vent, from the E flank of
the Southeast Crater, and along summit fumarolic fields. The
activity was observed directly and by utilizing surveillance
cameras situated in Milo (about 11 km ESE). The NW-SE-trending
fissure E of the summit craters continued (since 13 May 2008) to
produce active lava flows to the N of the SE end of the fissure,
along the W wall of the Valle del Bove. As of the 14th of March,
the INGV-CT reported that since two days on March 10, a
resumption of the explosive activity s' is produced on the "
boutonnière" located at 2800 metres of altitude under the
Southern crater East. This new explosive activity is accompanied
by an increase in the flow by lava flow which flows in Valle del
Bove. As of the 13th of February, the INGV-CT reported that to
date, the eruption which began in May 2008 continues. This
explosive and effusive eruption initially and maintaining only
effusive until to date continues; to run out within the interior
of Valle del Bove. Several transitory mouths pours small
castings the most advanced face of lava is with approximately
2000 metres. The activity of the summit craters is made up
exclusively by degasifications. The craters of North East and
that of Bocca Nuova western are the most active INGV-CT reported
that during 5-11 January activity from Etna's summit craters was
observed utilizing surveillance cameras situated in Milo (about
11 km ESE); inclement weather prevented direct inspection of the
summit area. Degassing was seen from the NW Bocca Nuova vent,
from the walls and floor of Southeast Crater, and along summit
fumarolic fields. The NW-SE-trending fissure E of the summit
craters continued (since 13 May 2008) to produce active lava
flows to the N of the SE end of the fissure, along the W wall of
the Valle del Bove. As of the 27th of November INGV-CT reported
that an inspection of Mt. Etna's summit craters on the 19th of
November revealed degassing from the Northeast Crater and, to a
lesser degree, from the Bocca Nuova BN-1 crater. A 100-m-long
lava flow was active in mid-November; the lava flow field on the
upper Valle del Bove has been active since the 13th of May. As
of the 23rd of September INGV-CT reported ( Charles Rivière
information) that the eruption which had started on 10 May this
year, still continues with weak emission of lava from the
fissure vents east of SE crater at 2900 m a.s.l. The lava
continues to flow into the Valle del Bove, but for most of the
time and its way, the active lava is hidden inside crusted-over
channels and tubes. The first snowfalls occurred today on the
tops. No change particular to the effusive mouth of 2800m,
several small castings run out in the top of Valle del Bove with
much of passage in the cave. The most advanced face of lava is
with approximately 2300m. As of the 16th of September it has
been reported by INGV-CT that the explosive and effusive
activity which began on May 10, 2008 has continued now for 4
months with the eruptive mouth of 2800 metres and the lava flows
run out inside Valle del Bove. The overflowing of lava is in
reduction compared to the previous week and at the last weeks.
However, on September 7th, in the evening, an increase occurred
with the presence of many transitory mouths and several
ramifications along the Western wall of the Valley of Bove. From
1930 hrs with the top of the effusive mouth, the cone which
before had a weak activity with a light degasification, left the
place with a weak Strombolian activity accompanied by light but
appreciable increase in emission of lava to the effusive mouth.
The explosive activity, with alternative phases, became
exhausted towards 2100 hrs approximately. Small isolated
explosions were observed thereafter with the effusive mouth
until 2300 hrs. With regard to the activity of the summit
craters the last observations do not present variations compared
to those observed during August. Degasification continues mainly
with the Northern Crater Is and the Western mouth of the crater
of Bocca Nuova. Lastly, the bottom of the crater Is of Bocca
Nuova entirely arises blocked by crumblings of walls. An
explosive activity is quite audible at the bottom of the
Northern crater Is, as could note it Pietro Vinciguerra, Carmelo
Cavallaro and of the colleagues of Soccorso Montana of Corpo
Forestale de Linguaglossa on the edge of the crater. The crater
of Voragine presents a modest degasification with localised
fields of fumerole along the internal walls. A weak
degasification is visible with the Crater of the South East with
fumeroles present along the edges of the crater. The values of
SO 2 flows recorded on Mt. Etna showed, in the first week of
September, an average of 3000 tonnes/day with a maximum of 4000
tonnes/day on September 3rd. This progressive increase was
accompanied by an increase in the volcanic tremor. As of the
24th of July it has been reported by INGV-CT that an inspection
of Etna's summit craters on 15 July revealed degassing from the
Northeast Crater and to a lesser degree from the BN-1 crater of
the Bocca Nuova. Explosive activity was restricted to Vent 2 of
the active NW-SE-trending fissure E of the summit craters and
characterised by weak Strombolian activity and diffuse ash
emissions. During 15 and 17 July lava flows were active in the
Valle del Bove. On 17 July, no explosive activity was seen along
the fissure. As of the 21st of July it was reported by INGV-CT
that that the eruption of the May 13th fissure at Mt. Etna
volcano continues. The lava flow into Valle del Bove is still
alimentated, although the intensity of spattering from the upper
vents at 2800 m elevation has decreased since the 17th of July.
As of the 4th
of July INGV reported that since the early of this afternoon
explosive activity from the buttonhole vent is generating an ash
plume. Lava are still flowing from this area into two arms. As
of the 27th of June, INGV reported that the eruptive plume was
still rose above the volcano, but the explosive activity ceased.
(www.ct.ingv.it).
New
Live cam Etna -
Etna monitoring page
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ITALY -
Stromboli volcano (Eolian Islands)
March
12th, 2010
As of the
12th of March, INGV-CT reported strong explosions from Stromboli
on 10 March mainly from craters located in the N part of the
crater terrace, a flat area in the upper part of Sciara del
Fuoco (a depression cutting the NW flank of the volcano). After
one of the more powerful explosions, lava flowed over the NW
edge of the crater terrace for tens of meters before fragmenting
and producing small landslides of hot material that likely
reached the sea. PREVIOUS NOTABLE NEWS . As of the 24th of
November, INGV reported that at 11.20 pm GMT on 23 november
2009, a strong explosive episode occured and generate an
important plume above the volcano. The falls of fragments
(lappilis, small bombs fallen around the summit area maily the
Pizzo Sopra la Fossa and east flank of the volcano. As of the
8th of October, INGV Catania, reported that a violent explosion
occured at 12:28 GMT from the summit crater of the volcano,
fragmenting and blowing out part of the eastern flank of the
cinder cone. The explosion produced an eruptive column more than
350 m high that was drifted SE by the wind. The explosion was
soon followed by a lava flow erupted from the widened central
vent. The lava flow spread within the crater depression for a
few minutes, and reached the maximum estimated lenght of ~60 m.
Lava flow within the crater depression formed also between 22
and 25 April, on 3 May, and on 30 August 2009. After the 8
November explosion, the explosive activity returned to the
background levels. PREVIOUS NEWS : as of the 20th of July, the
Global Volcanism Network (GVN) has reported that during the
period of the 6th-12th of July, eruptions continued from 4 vents
at Stromboli volcano in Italy. Two vents were active in the
north crater, and two in the south crater. The north crater
showed short eruptions which ejected bombs, lapilli and fine
ash. The intensity of eruptions was average, with emissions to a
height of 150 m above the vent. During the reporting period,
there were an average of about 15 explosions per hour.As of the
6th of April, the Volcano Discovery team has reported that as
observed during an ongoing tour with Dr. Tom Pfeiffer and a
small group, the activity at Stromboli volcano is usually
strong. Explosions from several vents, often accompanied by loud
thundering noises that can be heard on the whole island, occur
frequently from seveal vents, and often throw blocks and
incandescent bombs to up to 400 m height. Bombs are sometimes
hitting the trail and the Pizzo. PREVIOUS SIGNIFICATIVE
INFORMATION : As of the 8th of December 2008, the Instituto
Nazionale di Geofisica e Vulcanologia - Sezione di Catania has
reported a strong explosion occured on 6th of December at 8:48
PM. Duration of this phase has been about 2 mn, then some rocks
fallen on the upper part of the Sciara del Fuoco. Since, the
seismic and volcanic activity returned as previous and usuel
level. As of the 1st of November, the Instituto Nazionale di
Geofisica e Vulcanologia - Sezione di Catania has reported that
eruptions still continue at Stromboli. Mild Scirocco wind makes
for perfect visibility of the collapsed crater terrace, on which
four vents were erupting about twenty times per hour. After 8
June 2008, the activity at the E-W oriented eruptive fissure in
upper Valle del Bove increased. On the evening of the 13th of
June 2008 when the most active vent displayed very strong
strombolian activity reached altitudes of several hundred metres
above the vents. A similar eruption style had been present
during much of 2006 and sometimes in 2007.
Previous
information : after the effusive eruption which ended on 4th of
April this year and a powerful vent-clearing explosion on 15
March, there have been deep-seated explosions ejecting black ash
clouds since May. In July, these have beomce more regular and it
seems that the magma level inside the vents has been rising and
there could soon be visible lava ejections again. As of the 5th
of April, the Instituto Nazionale di Geofisica e Vulcanologia -
Sezione di Catania has reported that the lava flow issued from
Stromboli volcano stopped . Whether this is the end of the
effusive eruption that had started 5 weeks ago and heralds the
beginning of a new cycle of summit activity is still unclear. As
of the 30th of March, INGV eported that the lava continues to
flow on Stromboli. Three branches of lava flows originate at the
420 m vent on the Sciara del Fuoco, two of which still reach the
sea. As of the 22nd of March INGV reported that on 20 March,
lava emission from the 400 m vent on the Sciara del Fuoco
increased, accompanied by increasing levels of tremor. Two
well-alimented lava flow branches were present on the Sciara. On
21 March, tremor has decreased and thermal camera observations
show that at least one of the two branches were no longer
alimentated and cooling. On 15 March 2007, while the effusion
from the 400 m vent was still going on, a major explosion
occurred at 2037 GMT time. This event was similar to the 5 April
2003 paroxysm, and was recorded by all the INGV-CT monitoring
web cams. As the previous event, it occurred during a flank
effusive eruption, when the summit craters of the volcano were
obstructed by debris collapsed from the crater rims. As of the
9th of March, the Instituto Nazionale di Geofisica e
Vulcanologia - Sezione di Catania has reported that the eruption
at Stromboli that started on 27 February continued during
9March. Lava from a fissure on the NE flank of Crater 1 (the NE
crater) flowed down the Sciara del Fuoco and formed two branches
that reached the sea, resulting in steam plumes and a modified
coastline. A new eruptive fissure opened on the morning of 9th
of march at about 500 m elevation in the Sciara del Fuoco.
Explosive activity from the summit craters ceased when the lava
flowed from the fissure, but gas puffing accompanied by small
landslides inside the craters started again after 3 March. As of
2nd of March, INGV reported that Stromboli was calming down
since Thursday 1st of March, after spewing spectacular lava
flows for three days. During the night between 28th of February
and 1st of March, the flows of lava has decreased in importance
and was moving more slowly. Volcanic tremor remained weak.
Previous news reported that on 27th of February, the volcano had
been placed under heightened surveillance on Tuesday after
dicovering lava spewing from two faults located on Sciara del
Fuoco about 600 m elevation. One of the lava flow already
reached the sea. On Wednesday 28th of February , a third lava
flow outpoured from an active fissure. Following this increasing
of the activity, civil autorities decided to put its emergency
plan into action. According to italian scientists, for the
moment there is no sign of a large-scale collapse or important
flow that could induce a tidal wave. However, the situation is
under constant surveillance and all measures had been taken to
ensure the security of the population. Many buildings, including
two oil containers, have been evacuated as a precautionary
measure and residentss have been told stay away the coastline.
Several explosions per hour are still occurs from the summital
craters.(INGV). As of the 15th of September 2006, the Instituto
Nazionale di Geofisica e Vulcanologia - Sezione di Catania and
SVE team have reported that Stromboli has continued to be
exceptionally active in August and early September, with as many
as 10 vents emitting lava and steam rings occasionally being
produced. Stromboli is the northernmost of Italy’s Aeolian
Islands, Stromboli is simply the summit of a volcanic mountain
that rises up out of the sea. The volcano has been in a
virtually constant state of eruption since Roman times, and its
spectacular nighttime eruptions make it a popular
volcano-watching location. As 5th of May Stromboli Volcano
continued its normal "Strombolian" eruptions, with frequent
summit explosions.Previous significative information : as of the
1st of November 2005, the Instituto Nazionale di Geofisica e
Vulcanologia - Sezione di Catania has reported that a plume
emitted from Stromboli that may have contained ash was visible
on satellite imagery on 14 October at a height around 1.8-2.4 km
(6,000-8,000 ft) a.s.l. The plume extended ~10 km NW of the
volcano. Stromboli is one of the Aeolian Islands of Italy. It is
one of the most active volcanoes on Earth. It has been in nearly
continuous eruption for about 2,000 years. Explosive activity at
the summit craters of Stromboli volcano resumed on early June
2003, before the end of the effusive eruption that finished
between 21 and 22 July 2003. Eruptive activity at this volcano
is continuously monitored by INGV-CT using two web cameras
located at Il Pizzo Sopra la Fossa (920 m a.s.l.) and at 400 m
elevation along the east margin of the Sciara del Fuoco, the
depression on the north flank of the volcano that contains the
summit craters. Additionally, a web thermal camera is also
located at the 400 m elevation site, and a web infrared camera
at Il Pizzo Sopra la Fossa. The thermal and video cameras at 400
m elevation give important insights when visibility of the
summit is poor or craters are surrounded by clouds. The infrared
video camera at Il Pizzo allows a continuous view of the
activity at the summit craters, and a quantification of the
energy released by the explosions at the three summit craters
through an automated system called VAMOS (Cristaldi et al.,
2004). Explosive activity at the three summit craters increased
after 10 February 2004, leading to a significant growth of the
cinder cones inside the three summit craters. Several powerful
explosions, especially from crater 1 (the NE-crater) and crater
3 (the SW-crater) carried scoria 200 m above the craters. These
powerful explosions led to fallout of fresh bombs and lapilli on
Il Pizzo Sopra la Fossa in early March. Samples of lapilli and
scoria collected on Stromboli by local guides have been analysed
with the scanning electron microprobe and microanalysis
instruments of INGV-CT (Corsaro et al., 2004). Measurements of
glass compositions evidence that products erupted until 25
February 2004 belong to the “black scoriaceous volcanics”
normally erupted during Strombolian activity. No “golden
basaltic pumices” were present in available samples. Emission of
golden pumice at this volcano is generally associated with
paroxysmal explosive events (Bertagnini et al., 1999) such as
that of 5th April 2003. Analysis of components carried out on
several ash samples allowed us to recognize sideromelane and
tachylite as the main components, making up ~80% of the erupted
ash (Andronico et al., 2004). The activity of this volcano at
the time of writing (8 March 2004) can be described as
Strombolian activity, with variations in the number and
frequency of explosions within normally observed limits, and
intensity of explosions at the higher limit of commonly observed
activity. As of the 2nd of January, the Instituto Nazionale di
Geofisica e Vulcanologia - Sezione di Catania has reported that
a year after a tsunami was caused by the detachment of lava
material along the Sciara del fuoco, Stromboli volcano has
intensified its activity, launching scoriae and lapilli.
Technicians and volcano experts, who are constantly monitoring
Stromboli, have said that the situation is not alarming. The
Stromboli Web video camera showed a small explosion on 10
December that produced a plume to a height of ~1 km above the
volcano. No ash was visible on satellite imagery. From the
seismic point of view, not only explosive events are recorded
(sufficiently deep that no visible strombolian activity is
associated to them in the crateric area), but also events
related to the continuous small rockfall episodes that continue
to descend along the Sciara del Fuoco- INGV-CT webpage
www.ct.ingv.it.
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ICELAND
- Eyjafjallajökull volcano
May
8th, 2010
As of the
7th (19h30 GMT) latest IMO-IES bulletin reported that explosive
activity seems to have decreased since yesterday. The ash plume
does not rise as high into the air and is lighter in colour.
Steam rises from the lava tongue under Gígjökull, which is a
sign that ice is melting in the tunnel, but to a much lesser
degree than when the lava flow was at its peak. The cinder cone
continues to build up around the eruption vent in the ice
cauldron. The lava flow to the north has been stagnant for the
past two days. Tremor levels are low, comparable to yesterday
and the period 14-17 April. Earthquakes are still being recorded
at 5-13 km depth, but fewer than yesterday. There are no signs
that the eruption is ending. Following the increasing of the
explosive activity on Thursday, during the last 12 hours,
explosivity decreased and stayed relatively stable on Friday 3
PM (IMO-IES). As of the 6th of May (18h GMT), new icelandic
bulletin reported that explosive activity has increased and
effusive part has decreased for the last two days. This results
in a higher eruption column with increased tephra fallout. The
ash plume observed from commercial pilots between 0530h and
0800h: 30,000 ft/9km Earthquake activity is still being
recorded. At least 10 earthquakes have been located since
midnight. Most of the earthquakes are sourced beneath or south
of the top crater in the eruptive conduit that has formed since
3 May. Most of the earthquakes are less than magnitude 2, the
biggest M2.2. Three events have been recorded beneath the
southeastern ice cap, depth uncertain. GPS Measurements from
around Eyjafjallajökull show continued horizontal displacement.
South of the eruption, stations THEY and SVBH have begun to
drift southward, whereas FIM2, located east of the eruption,
shows northward motion. No further northward motion has been
observed at STE2, located to the north. Today's displacement
pattern suggests deformation beneath the southeastern part of
Eyjafjallajökull. There are no signs that the eruption is about
to end. As of the 5th of May (report 18h GMT), the eruption
sight was not visible. From the flight of the Icelandic Coast
Guard (ICG) 04.05.2010: The crater continues build up in the
northern most ice cauldron. Lava flows to the north and spreads
at 500 m a.s.l. The lava tongue is about 200 m wide and lava
channels that join at the tongue are about 30-60 m wide. The
lava channels gets wider every day. Continued seismicity,
between 20 and 30 earthquakes have been located beneath the ice
cap since 3 May, first deep (18-23 km) and then also at 2 km.
Increased seismicity suggests that new material is intruding
from deep below Eyjafjallajökull and latest GPS-observations
suggest inflation. Significant changes in horizontal movement at
GPS stations around Eyjafjallajökull have been observed in the
last 48 hours. Renewed northward displacement is seen at
stations BAS2 and STE2, located just north of the ice cap. To
the south, westward movement is apparent at THEY, while station
FIM2 - located further east - shows eastward movement. So far,
GPSsignals are not large. There are no signs that the eruption
is about to end. Previous IMO-Institute of Earth Sciences
bulletin (May 4th - 15h GMT)reported that explosive activity and
ash production was strong and increased since yesterday. Dark
ash plume rises above the crater. Lava is still flowing
northwards, forming a lava fall down the steep hill under
Gígjökull, about 4 km north of the crater. Blue gas is seen
rising from the lava and white steam plumes are seen somewhat
lower and mark the front of the lava stream. Radar images from
ICG-flight today show tunnels in Gígjökull increasing in size
and continuing the build up of the cone at the crater. The size
of the eruptive crater is 280 x 190 m. Lava splashes are thrown
at least a few hundred meters into the air. Plume observed at
5.8-6 km height (19-20,000 ft) estimated from the Icelandic
Coast Guard (ICG) flight at 10:40 and 15:30 GMT. The plume has
also been observed on IMO's weather radar at 5.2-5.4 km height
between 13:05 and 14:00 GMT. As of the 4th of May, the eruption
is continuing. On the morning this day, the webcam showed that
Eyjafjallajökull erupted a fairly vigorous steam-and-ash plume
from its main vent. Steam plumes could be seen rising from the
gully where lava is interacting with meltwater as it descends
the slope. The main ash plume has been varying in height (the
IMO bulletin and VAAC reports indicate up to around 5.5 km
altitude) and density yesterday and today; Tremor has reduced
since the IMO issued its bulletin, but there have been more
earthquakes under Eyjafjallajökull over the last 24 hours, some
shallow (1.1-2.2 km) but some very deep: between around 21:00
yesterday and 01:00 today there were four quakes of magnitudes
between 1.4 and 1.8, at depths varying from 13.0 to 21.6 km.
There also appears to be a north-south alignment to recent
earthquake activity. No measurable geophysical changes within
the Katla volcano. As of the 2nd of May (9PM GMT) IMO and
Institut of the Earth Sciences reported that the eruption is
mixed, with the lava-producing phase being larger than the
explosive phase. During the last 2–3 days, the plume has been
darker and wider than in the preceding week. Tephra fall-out in
the vicinity of Eyjafjallajökull has increased. From the
location of the steam plume over Gígjökull, lava has advanced
over 3 km north of the eruption. Steam plumes over the glacier
edge from 19:40 GMT suggest that lava may have advanced even
further. A rough order-of-magnitude estimate of lava volume can
be obtained from the dimensions of the ice canyon. This estimate
gives a lava production rate of-the-order 20 m 3 /s (i.e. 50
tonnes/s). The explosive phase may be 10–20 tonnes/s. The
explosive phase has increased somewhat in intensity during the
last few days. Presently, there are no measurable indications
that the eruption is about to end. As of the 30th of April, IMO
and Institut of the Earth Sciences reported that Plume
elevations and magma discharge levels remain similar to the
preceding seven days of activity. A spatter cone continues to
grow in the northernmost crater. Lava continues to flow north
from the eruption site and down the Gígjökull glacier. This day
explosive activity and ash production represents a fraction of
conditions during the height of the eruption (14–17 April).
Presently, there are no measurable indications that the eruption
is about to end. As of the 29th of April, Institut of the Earth
Sciences reported that yesterday evening conditions at the
eruption site are thought to be similar to the preceding five
days. Lava continues to flow northward, where it now descends
partway down the Gígjöjkull glacier. Seismic tremor: Intensity
comparable to the preceding five days of eruptive activity. Gas
emissions from meltwater leaving Gígjökull represents a
localised hazard, especially within the moraines of the glacier.
The main gasses are CO2 and probably SO2. These gases are
heavier than air, and could linger in front of Gígjökull if
light winds prevail. Plume elevations and magma discharge levels
remain similar to the preceding days of activity. Despite a
single earthquake occurring, there are no signs of untoward
changes within the Katla volcano. As of the 28th of April,
following a flight of the Coast Guard, radar pictures confirmed
that the crater has expanded to 200 meters in diameter and has
grown 150 meters tall.The volcanic cloud was light in color,
stretched to the east and three to five kilometers up from the
crater. Ash fall was insignificant. Rumbling could clearly be
heard from the eruption site but no lighting has been seen in
the volcanic cloud since April 19. Lava was flowing underneath
the glacier to the north of the crater and was melting the ice
above and to the sides. There are no indications that the
eruption is drawing to a close. As of the 27th of April,
activity is still continuing. Yesterday, the eruptive plume
height was between 3.9.- 4.8 km. No ash-fall reported, although
light ash-fall possible over Mýrdalsjökull. Report from ~20 km
SE of the volcano of booming sounds (02:30 GMT) Continuing
discharge of water from Gígjökull due to ice-melt at the
eruption site. Discharge at the old Markarfljót bridge, 18 km
from Gígjökull, is estimated at 110–130 m 3 / s, of which 30–40
m 3 /s is baseflow. No visual observations due to bad
visibility, but. radar images show continuous build-up of a
tephra crater/cone in the northern ice cauldron. The diameter of
the crater is 200 m and the height of the crater cone is 150 +-
20 m. the seismic tremor intensity remained comparable to the
last three days of eruptive activity.Earthquakes: Ml 1.7
earthquake detected ~8 km east of the eruption at 16:18 GMT.GPS
deformation: Horizontal displacement towards the centre of the
volcano, in addition to vertical subsidence. These observations
are consistent with deflation of a magma reservoir beneath
Eyjafjallajökull.. There was no visible lava flow but total
magma flow considered similar as last two days (20–40 tonnes/ s.
No measurable geophysical changes within the Katla volcano.
Earthquake activity on the north-western edge of Vatnajökull is
unconnected with the ongoing eruption. Magma flow-rate and plume
height has remained at similar levels during the last few days.
Lava continues to flow northward. No signs of melting or
meltwater discharge towards the south. There is no indication
that the eruption is about to end; however, it is an order of
magnitude smaller than in the first explosive phase. As of the
24th of April, Norvulc reported that North crater still active.
Mild explosive activity with spatter thrown to 100 m height
above crater. Shockwaves occur every few seconds. North of
crater a roughly 300 m long and wide depression has been melted
out in the last three days. Steam plumes rise from the
depression, especially at the margins. This is explained by lava
flowing northwards from the crater with the steam rising where
lava meets ice. Magma flow rate has remained at similar level
over the last few days. Plume activity is gradually declining.
Flow of lava is considered to have began around noon on
Wednesday 21 April. Timing is based on: a) onset of
semi-continuous discharge of meltwater from Gígjökull, b)
Observations of steam rising at northern margin of ice cauldon
at 1300 on 21 April, and c) a change occurs in fluctuations in
tremor amplitude at this time. No signs of melting or meltwater
discharge towards south. No signs of termination of eruption. As
of the 22nd of April, University of Iceland reported that
Eruption was with similar situation as yesterday (see 21 April
report).Seismic tremor recorded by the Icelandic Meteorological
Office: Some fluctuations, with a peak shortly after midnight 22
April related to a small flood of meltwater. Since the onset of
the explosive eruption the tremor has overall been gradually
increasing, with superimposed fluctuations. Visual observations
yesterday: Regular explosions at intervals of few minutes were
observed in afternoon, with fluctuations in intensity and tephra
content. As of the 21st of April, Norvolc, University of Iceland
reported that the eruption continues with less explosive
activity. Eruption rate is inferred to have declined over last
few days and now be an order of magnitude smaller than during
the initial 72 hours of the eruption. Present eruption rate is
estimated to less than 30 m3/s of magma, or 75 tonnes/s , with a
large uncertainty. The northernmost one of two main craters in
the summit caldera is active. Phreatomatic explosive activity
occurs with some lava spatter at craters. Plume height is about
3 km. Tephra dispersal: local towards the south. Meltwater
isminor, but what is melted flows down into Markarfljót, no
signs of water accumulation in craters. Seismic tremor recorded
by the Icelandic Meteorological Office showed some fluctuations
but mostly stable. Tremor is not decreasing and does not reflect
the decline as inferred for the eruption rate. GPS-measurements
indicate continuing small pressure decrease under the volcano at
a similar rate. Samples collected April 19 show same composition
as early in the explosive phase, but fluorine content is higher.
Samples collected 19 April have 850 mg/kg (initially it was
25-35 mg/kg). This is due to the change in eruptive style –
tephra is now not washed to the same extent by water in the
eruptive plume. Amount of erupted material: Uncertain but on the
order of 100 millon cubic meters. Tephra next to craters is
20-30 m thick.
New video taken on 20th of April. As of the 20th of April,
according to a local volcanologist, a flight yesterday showed
that a cone is being built up and magma was seen thrown up in
the air and then falling down on the rim of the cone. Jeeps size
bombs were being shown thrown up in the air. However, NO lava
FLOW as such. No water was seen in the cone so we are probably
seeing much less magma water interaction due to the protection
of that cone that has been built up which would explain why the
plume does not rise as high and form as much ash. However there
is still some plume. First flights of news media around the
volcano this morning seemed to indicate less activity than
yesterday, which probably just means even smaller plume. The
tremor has stayed fairly constant (pers.com). As of the 19th of
April, Team member Björn Oddsson at the University of Iceland
Institute of Earth Sciences said a cloud of smoke still rises
from the crater but it is light in color and doesn't contain
much ash. The cloud also doesn't extend as high into the air
anymore, which is an indication that water doesn't flow into the
crater. As of the 18th of April in the morning, latest news
reported that the eruptive activity is continuing. During the
night the volcanic tremor increasing. According to our icelandic
colleague, they have a rough estimate of now much that pocket
shrank based on very simple modeling in the first two days of
current eruption about 4 million m3. During the first phase of
the eruption outflow was estimated at the rate of about 15 m3/s.(pers.com).
The quantity
of fluor is approximately 25-35 mg/kg according to chemical
analysis carried out by the Institute of Earth Sciences,
University of Iceland. Regarding any speculation on the climate
impacts of this eruption to date, measurements by the Ozone
Monitoring Instrument (OMI) on April 15 revealed only ~ 4
kilotons of SO2 in the volcanic cloud. Data from April 16 show
reduced amounts.
As of the 17
of April, in the morning eruptive activity was still continuing.
Yesterday, April 16 some variability occurs in seismic tremor
and tephra generation, but overall the eruptive activity remains
stable. Pulsating eruptive plume reaches above 8 km, with
overall height of 5 km. Large closures of airspace continue.
Chemical analyses of ash samples reveal fluorine rich
intermediate eruptive products with silica content of 58%, more
evolved than in the initial lava producing phase of the eruptive
activity. The magma composition may reflect evolution from
alkali-olivine basalt by crystal fractionation as erupted in the
initial phase. As of the 16th of April, newspaper reported that
last night it was decided that flights would be banned in the
greater part of northern Europe, at least for the first half of
today because of drifting ash ejected from the Eyjafjallajökull
volcano. The silica glass shards that make up most ash can melt
inside jet engines, causing them to stall - which could lead to
crashing. Probably the production of ash will continue at a
comparable level for some days or weeks. But where it disrupts
travel, that depends on the weather: On Thursday, scientists got
the first radar pictures of the craters in Eyjafjallajökull.
Until then it had been impossible to take such photos. The
pictures show three craters and how large they are. At the time
of the flight the flood from Gígjökull was beginning and the
scientists could confirm that a gigantic flood was making its
way towards Markarfljót. The flood has since subsided. As of the
15th of April, Newspaper reported that Markarfljót river to the
west of Eyjafjallajökull glacier flooded for the second time
last night. The second flood was completely unlike the first
one. The floodwater in the first flood was 3.5-t degrees Celsius
and contained almost no ice. In the second flood the water was
close to 0 degrees and cotaining a thick layer of ice chunks,
often 5-15 centimeters thick. The explanation for the difference
between the two floods is that in the first one the water came
from a lagoon by the glacier but the second flood was melted ice
from the glacier. According to mbl.is Sigurdur Reynir Gíslason,
geologist at the Geological institute at the University of
Iceland, last night, the fissure in the volcano was doubtless
melting more ice. Air traffic in north Norway has now been
banned due to fear that ash fall from the volcanic eruption in
Eyjafjallajökull glacier in south Iceland might reduce
visibility. Yesterday, 1PM last report showed that The eruption
was many times larger than the eruption in Fimmvörduháls.
Information gathered from scientists on board the Coast Guard
airplane TF-SIF showed that the total length of the fissure is
about two kilometers. The fissure lies north-south. That is a
large fault trough (graben) has formed around the crater which
is up under the summit of the glacier. There is ash fall to the
east close to the Fimmvörduháls. The cloud of volcanic ash and
smoke has now risen up to 22,000 feet. The eruption is only in
the top crater, not in the southern sides. Armannn Hoskuldsson
of the University of Iceland reported that the eruption is
purely explosive, with no signs of lava flows, most likely due
to the abundant water near the vents. The glacial river is in
flood, 1,000 cubic meters per second, and is increasing. A huge
flood is on its way down the Markarfljót sands and the old
bridge is submerged. To try and save the new Markarfljot bridge,
the Ring Road was broken up to the east of the river. As of the
14th of April, news reported that two airplanes flying over
Eyjafjallajökull this morning indicated that smoke is coming up
in a new place to the south west of the eruption in
Fimmvörduháls. During morning all indications are that a new
eruption is starting in Eyjafjallajökull glacier. Rivers are
growing bigger and smoke was seen over the glacier this morning.
Residents of the area were evacuated but some were allowed to go
to their farms to attend to animals this morning. Geologist said
that indications are that an eruption has started under the
glacier just before seven o'clock. Markarfljót, the biggest
river close to the glacier is growing at a fast rate. At this
moment it is difficult to estimate the size of the eruption. The
eruption has now been confirmed but no magma has been seen
yet.Earthquake activity started late last night in the area.
Roads to the area have been closed both from the east and the
west. They have confirmed that there is glacial flooding on both
sides of Gígjökull and that the water level in the lagoon in
front of the glacial tongue is constantly increasing. The water
that flows into the lagoon is dark in color. However, the water
flow has yet to reach the peak of spring thaw. Visibility is
still very limited in the area but an airplane's crew has
spotted a cloud of volcanic ash and smoke which extends 12,000
to 14,000 feet into the air and appears to be coming out of the
glacier's summit. Magma is melting its way through the icecap;
there is a circular ice free area by the summit measuring
approximately 200 meters in diameter. Yesterday scientists
indicated that the eruption in Fimmvörduháls could have ended.
New video eruption As of the 12th of April, last
scientific report showed that seismic tremor reaches a minimum -
eruption stops? As of the 11th of April, the Institute of Earth
Sciences University of Iceland reported that eruption tremor
approaches pre-eruptive levels, but visual observation reveal
eruptive activity in late afternoon. As of the 9th of April, the
Institute of Earth Sciences University of Iceland reported that
after little change in deformation rates during the eruption,
timeseries at continuous GPS-stations north of the volcano show
sudden change, partly jumping back to pre-eruptive levels.
Signals may relate to decreasing pressure in the magma conduit
feeding the eruption. some data about the eruption. They
measured the size of the new volcano which has formed around the
craters on Fimmvörðuháls. The area of the new lava is now 1.3
square kilometers, the average thickness is 10-12 meters and
estimated volume of eruptive material 22-24 million cubic
meters. Accordingly, the average flow rate has been
approximately 15 cubic meters per second since the eruption
began. The eruptive cone stands 82 m above previous ground level
and the highest peak is 1067 m a.s.l. As of the 8th of April,
there is significant activity in the new volcanic crater on
mountain pass while the original crater has ceased spurting
lava-for now, at least. However, the lava still seethes in the
older crater. A broad lava stream now extends to the west of the
Hvannárgil canyon and flows one or two kilometers per hour. Blue
volcanic fumes extend from the older crater but there are no
explosions. That is an indication that the crater was cooling
down. Aerial pictures showed that there was still a seething
lava pool within the closed crater. There is quite a lively
activity in the new crater and a lot of lava that flows from it.
There are no indications for the moment that the eruption is
about to stop. As of the 7th of April, news reported that there
haven't been any changes to the nature of the eruption. Activity
has stopped in the original craters of the eruption, and is
limited to craters on the new fissure formed on 31 March. Lava
flows cover an estimated area of 1.3 square kilometers, with
estimated average thickness of 10-20 m. Maximum elevation of
scoria craters formed in the eruption is 82 m. The Civil
Protection Department emphasized yesterday that all traffic on
Eyjafjallajökull is prohibited and the area in a one-kilometer
radius around the crater on Fimmvörduháls is closed. As of the
5th of April, the eruption continued with little changes. On
April 4th, lava flowing to the west encountered some patches of
glacial ice, causing some water discharge into river Hvanná,
steam plumes and low frequency tremor bursts. NASA satellite
image shows the eruption on April 4, 2010. The original
fissure—originally about 1,000 meters (3,000 feet) long and
composed of several distinct vents—has coalesced into a single
vent. The new fissure is hidden under a volcanic plume, likely
composed primarily of steam. Black lava flows reach several
kilometers north from the vents, eventually spilling into
Hvannárgil and Hrunagil Canyons As of the 2nd of April, a report
in Morgunblaðið puts the length of the new fissure at 300
metres, and its location as 200 metres north of the initial
location of the eruption, while RÚV reports the length as
300-400 metres. The new fissure trends north-south, roughly at
right angles to the east-west alignment of the first fissure.
The Icelandic Met Office have published an article looking at
what the patterns of seismicity at Eyjafjallajökull reveal about
the path of the magma over the period from the 13th-24th of
March: "The magma path revealed". It seems that the main feeder
conduit for the eruption is situated beneath the eastern part of
the Eyjafjallajökull ice-cap and rises nearly vertically to
around 2-3 km depth, and then changes direction to run
horizontally eastwards for about 4.5 km to the point outside the
ice margin where the eruption began on the 21st of March. Police
estimate that up to one thousand people went to the eruptions
site at Fimmvörduháls after the place was opened up again
Thursday afternoon. The eruption remained similar in strength as
before. As of the 1st of April pilot reported that at just
before seven P.M. on Wednesday 31st of March a new rift opened
up. The split went south towards the other crater. The new rift
is not in the same direction as the old one, this one goes from
north to south. The new row of up to seven craters is closer to
Thórsmörk and came up in the middle of the flowing lava forming
the “lava fall” into Hvannárgi. After a new crater formed on
Fimmvörduhals on Wednesday night, the site was closed to all
traffic. This change was not accompanied by any detectable
seismic activity, neither tremor nor micro earthquakes. Most of
the lava seems to accumulate near the vents, but there are
intermittent flows into the gullies of Hruná and Hvanná. As of
the 30th, Volcanic activity at the crater increased yesterday
afternoon 29th of March after having subsided the night before
and yesterday morning. From a helicopter on 28 March, scientists
saw lava flowing into both canyons and noted fewer jets of lava.
Shortly after 6 pm last night a series of earthquakes measuring
2-2.5 on the Richter scale shook the region. Geophysicist Gunnar
B. Gudmundsson at the Icelandic Meteorological Office noted that
seismicity was gradually decreasing and was an indication of the
force of the eruption is gradually decreasing. He added that GPS
monitors that measure tectonics show that the lithosphere has
ceased expanding and even contracted a little. However, that is
no certain indication that the eruption is about to finish.
Roughly estimated, 15-20 million cubic meters of solid volcanic
debris might have spurted to the surface from inside the earth
since the eruption began on March 21, said geophysicist Magnús
Tumi Gudmundsson. The lava now covers approximately one square
kilometer.As of the 29th of March, the eruption in the
Eyjafjallajökull volcanic system has been on a small scale so
far, and tremors signal are diminishing, at least for the time
being. Lava has flowed north into two gullies, either side of
Heljarkambur ridge. It has been predicted that lava might reach
the river Krossá within a few days. Krossá flows due west, north
of Eyjafjallajökull, and into the larger river Markarfljót. As
of the 26th of March, the webcams appear to show diminished
activity (although the reduction of ice and snow in the vicinity
of the eruption through melting may also be playing a role in
reducing the scale of the eruption plumes). Lava effusion issued
from the Northeast of the eruptive fissure. Strombolian activity
remained from the Northernmost cone. A warning has been issued
about toxic plume in the vicinity of the eruption: sulphur,
flourine, carbon dioxide and carbon monoxide are being released
by the activity. Seismically things appear relatively stable
underneath Eyjafjallajökull and Katla and there is little sign
of the latter stirring, although preparation are under way
locally, just in case. As of 24th of March, the
latest observations from Iceland on the Eyjafjallajökull fissure
eruption have been limited by poor weather and low visibility,
but overall the activity, located at Fimmvörduháls between
Eyjafjallajökull and Myrdalsjökull, does not appear to be
changing significantly in character. As of the 22nd, the
volcanic activity was increasing slowly but surely, according to
an estimate of scientists who flew over the eruption zone in the
afternoon. The lava flow from the crater is spreading out over a
larger area and the eruption is becoming more forceful.
Visibility was limited to begin with but then the weather
cleared up and the scientists could see the eruption clearly;
the lava is flowing down a canyon south of the craters on the
pass and clouds of steam rise up from where the lava melts ice
and snow. As of 22nd of March, an increase in activity at the
Fimmvorduhals eruption on the morning has led to the no-fly zone
in southern Iceland being widened. Volcanic activity near the
Eyjafjallajokull glacier increased significantly at around 07.00
this morning, with a series of explosions sending a gas and ash
cloud 4km into the air. Geologist Hjörleifur Sveinbjörnsson at
the Icelandic Meteorological Office reported that the activity
which increased about an hour ago was decreasing now at about
8:30 AM. Instead of a large cumulus there are now small puffs,
yet they release a large amount of volcanic debris into the
atmosphere. The jet from the eruption zone reaches a height of
approximately eight kilometers and is light in color. It is
likely that it is mixed with water, which indicates that a steam
explosion with an increased volume of water has entered the
system. The eruption is under constant observation by the
Icelandic Meteorological Office and the coordination center in
Skógarhlíd in Reykjavík remains active. Geophysicist Páll
Einarsson has pointed out that there is a connection between the
volcano in Eyjafjallajökull and the neighboring volcano Katla
underneath the Myrdalsjokull icecap. The current eruption could
trigger a larger eruption in Katla.
As of the
21st of March, according press agencies and VAAC, the volcano
near the Eyjafjallajoekull glacier began to erupt shortly on
20th of March before midnight, leading to road closures in the
area. Several hundred people have been evacuated from their
homes. The initial visual report of the eruption was at 23:52
GMT, when a red cloud was observed at the volcano, lightening up
the sky above the eruptive site. The eruption was preceded with
intense seismicity and high rates of deformation in the weeks
before the eruption, in association with magma recharging of the
volcano. Immediately prior to the eruption the depth of
seismicity had become shallow, but was not significantly
enhanced from what it had been in the previous weeks.
Deformation was occurring at rates of up to a centimetre a day
since March 4 at continuous GPS sites installed within 12 km
from the eruptive site. The eruption broke out with fire
fountains and Hawaiian eruptive style on about 500 m long NE-SW
oriented eruptive fissure at N63º 38.1', W19º 26.4' on the
northeast shoulder of the volcano at an elevation of about 1000
m. It was observed from air from 4-7 A.M. on March 21. Lava
flows short distance from the eruptive site, and minor eruption
plume at elevation less than 1 km was deflected by wind to the
west. Volcanic explosive index (VEI) is 1 or less. Tephra fall
is minor or insignificant. The eruption occurs just outside the
ice cap of Eyjafjallajökull, and no ice melting is occurring at
present. Satellite data is being used to study the eruption and
associated intrusion. Several MODIS thermal images on 21 March
show a temperature anomaly where the eruption is occurring.
ENVISAT ASAR images before and during the eruption have been
acquired, and a series of TerraSAR-X images cover the area.
Ashfall occured in the town of Fljotshlid, located to 20km
Northwest -
NVI images shows an eruptive fissure with lava fountains and
lava flows - Also map of localization. Geophysicist Freymódur
Sigmundsson reported that the volcanic activity seemed stable
the three hours he watched the eruption from a circling airplane
this morning. It is possible that the rift will grow longer as
time passes by. Lava is flowing in two directions, to the east
and the main stream to the west. Because of heat turbulence it
was impossible to fly over the western stream. The direction of
the row of craters is a bit unusual, going from north to south.
Most of the rifts go from east to west. At the moment it seems
unlikely that the eruption will lead to a major flood as would
happen when an eruption starts under a glacier. As of the 5th of
March, the the Department of Geophysics, University Of Iceland
reported that the Icelandic volcano Eyjafjallajökull has been
very restless recently. The current seismicity and apparent
inflation may be precursory to an eruption, or it may not - this
kind of activity has been seen before, associated with dyke
intrusion events (although the current seismicity is unusually
energetic) and it is not possible at the moment to say whether
this time it will end in an eruption. An interesting detail
about the current activity comes from a source in Iceland who
tells me that magma degassing under Eyjafjallajökull produced an
'acid pulse' that led to local water supplies become temporarily
acidic about a month ago. Eyjafjöll (also known as
Eyjafjallajökull) is located immediately west of Katla volcano.
Eyjafjöll consists of an E-W-trending, elongated ice-covered
basaltic-andesite stratovolcano with a 2.5-km-wide summit
caldera. Fissure-fed lava flows occur on both the eastern and
western flanks of the volcano, but are more prominent on the
western side. Although the 1666-m-high volcano has erupted
during historical time, it has been less active than other
volcanoes of Iceland's eastern volcanic zone, and relatively few
Holocene lava flows are known. The sole historical eruption of
Eyjafjöll, during December 1821 to January 1823, produced
intermediate-to-silicic tephra from the central caldera. More
recently an intrusion at Eyjafjallajökull in 1999 appears to
have been followed by a small subglacial eruption in the Katla
caldera.
Video 24th of March -
webcam - SVE Press contact
about this eruption
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FRANCE -
Piton de la Fournaise (Reunion island)
January 12th,
2010
As of the
12th of January, OVPLF reported that the eruption ended.
Following a slight increasing of the eruptif tremor yesterday,
eruption within the Dolomieu crater dropped during this night at
about 2 am. Nowthe moment only a weak degassing occurs. As of
the 7th of January, the volcanic eruption begun January 2nd of
this year is always was still progress in the crater Dolomieu.
Yesterday evening, the eruptive trémor weakly increased but
remained stable. As of the 5th of January, OVPLF reported that
intensity of the at present current volcanic eruption in the
sommital crater Dolomieu is stable. It is however necessary to
indicate from time to time some renewals of activity comparable
to one pulse of more important intensity. This day two of these
phases were observed at 9:30 am and 11:30 am (GMT 4).A mission
of measure of the deformations of the sommitale zone led this
morning also allowed a visual recognition of the activity. Some
lava flows and a main eruptive vent remained active. As of the
4th of Jnanuary OVPLF reported that eruptive activity was
continuing but with a reduced outflow.. Only lava fountains with
small high and one active lava flow were visible. Tremor was
slighly decreasing but remained stable. An aa lava flow covered
about 90% of the 2008 flow on the floor of the Dolomieu crater.
As of the 2nd of January, OVPLF reported that Piton de la
Fournaise volcano erupted this day at 14:30 local time (GMT +4).
The eruptive fissure is situated in the cliff around the Bory
and Dolomieu summit craters. Some lava fountains tens of metres
in height have been observed during a reconnaissance jointly
carried out by the Gendarmerie Nationale (PGHM) and the Piton de
la Fournaise Volcanological Observatory. During this
reconnaissance, lava flows were observed flowing in the interior
of Dolomieu crater. significant landslides and cliff collapses
within Bory crater were also recorded. These collapses fuel
eruption plumes of ash and gases that are rising above the
summit craters of Piton de la Fournaise. This eruption was
preceded over two hours by a seismic crisis commencing at 12:00
local time. A small plume of volcanic gas from the eruptive zone
was already observed around 12:00. After some minutes of calm,
an eruptive tremor appeared on the screens of the seismological
network of the observatory at 14:25. PREVIOUS ERUPTION : As of
the 15th of December, OVPLF reported that the Piton de la
Fournaise volcano erupted Monday, December 14, 2009 at 18:45
(local time GMT +4). The eruption was preceded by a seismic
crisis and a raise of the summit area deformations, which
started at 17:30 (GMT +4). The eruptive tremor began at 18:30
(GMT+4). A system of sub-parallel fractures along the summit of
Dolomieu crater fed lava flows on the southern slope of the
Piton de la Fournaise, inside the Enclos Fouqué. A second
fissures system opened on the eastern flank of the Dolomieu
summit crater at 20:25 (GMT +4). Then lava flows were spent
towards the eastern slope. This eruption ended during the night
at 00h40 (GMT +4) after a gradual decrease in magma supply from
midnight (local time). This morning, Tuesday, December 15, 2009,
a visible degassing in the south and southeast fractures is
associated with a low intensity eruptive tremor. All of the lava
flows was confined to high zone of the volcano and more
specifically the slopes south and south-east of Piton de la
Fournaise. As of the 6th of November OVPLF reported that on
November 5, an intense seismic swarm occurred between 7:30pm and
8:30pm (GMT +4) at about sea level, including an earthquake of
80 seconds. This crisis was followed by a 30 minutes aseismic
phase and then by sustained tremor. The first vent opened at
8:50pm on the southern cliff inside the Dolomieu crater. At
9:05pm, a fracture propagated towards east on the upper
south-eastern flank of Piton de la Fournaise feeding a first
lava flow. A 9:20pm, a second fracture opened on the eastern
volcano flank between 2450 and 2300m asl. The eruption was also
recorded by the three webcams of the observatory, which,
together with the deformation and tremor patterns, allowed a
rapid identification of the eruption sites. The fractures fed
strombolian activity, small (about 20 meters high) fountains and
aa lava flows, which were visible from the national road lining
the coast in the Grand Brûlé area. At 3:00am on November 6, the
eruptive tremor declined to a very low intensity level. A first
survey on the volcano summit at 7:30am confirmed that the lava
fontaining was no longer active and the lava front had stopped
at about 1900 m elevation. At 9:00am the eruptive tremor
disappeared, thus confirming the end of the eruption. As of the
30th of October, OVPLF reported that the seismicity was still in
light increase. A new seismic crisis occured on the morning of
03:00 to 06:00 (local time). The hypocentres are still localised
under Dolomieu. Volcanologists of the Observatory noted a
partial migration of the earthquakes and deformation towards the
North (this could be due to injection of a dyke towards north).
The level of alarm remains to 1. As of the 23rd of october
OVPDLF reported that during the day before (22nd of October) 18
earthquakes occured, but no eruption started yet. As of the 21st
of October,OVPDLF has reported that seismic activity indicates
magma is probably within 500 m of the surface. A change in the
chemistry of volcanic gases appeared for the first time
yesterday since the outbreak of volcanic alert on the 4th of
October. The whole of these observations clearly confirms the
progression of the magma towards surface. An eruption thus
remains possible in the short or medium term. The level of alarm
remains to 1 for the moment. On 18 October, OVPDLF reported that
another seismic crisis was noted along with deformation on the N
and S sides of Dolomieu crater. Aerial observations on 19
October revealed a small new fumarole in the crater. Changes in
the chemical composition of the gases were also noted. A greater
number and duration of rockfalls than in previous days was
detected on 20 October. As the the 17th of October (09:30 am)),
OVPF reported that during past night (16th to 17th of October),
the frequency and the intensity of the seismicity were in
progressive increase. The trend of progressive deformation of
the volcano was confirmed, in particular on the side the North
of Dolomieu and close to the Dolomieu crater.Collapses of small
volume inside Dolomieu were registered.No variation of the
chemical composition of gases was noted. Previously, a new
seismic crisis started on 14th of October at 8:09am (local time)
and ended at 10:04am. This important seismicity was associated
with weak ground deformation of the North flank of the Dolomieu.
The day before 79 earthquakes have been recorded, mainly in the
areas mentioned above. As of the 9th of October, The observatory
of the Piton de la Fournaise reported that the seismic crisis
that occured yesterday ended on 8th of October in the morning at
10:57 am. This seismicity was located beneath the volcano summit
under craters Bory and Dolomieu. This phase has been associated
with weak North flank deformation of the Dolomieu crater. No
chemical variation in gas was noted. Previously, as of the 7th
of October, the Institut de Physique du Globe de Paris from the
Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)
reported that seismic activity increased on 7th of october in
the morning from 8:30 am and since remained at high level. Not
eruption occured yet, but local prefecture of the Reunion issued
the alert level 1. Enclos Fouqué entrance has been closed .
Yesterday 6th of october, 120 earthquakes were registred from
the network accompanied with sligh ground deformation. Previous
eruption started on 14th of December 11 PM (TU) ended on 4th of
February at 8 PM (TU). On February 2nd, 21 earthquakes were
recorded including one with mag. 2.2 accompanied with a
decreasing of the volcanic tremor. As of the 3rd of February
seismic activity increased again and tremor decreased. In the
morning, only one lava flow was active on the Northwest side.
Between 8-9th of January, two earthquakes located above the sea
level were recorded (max = 1.5 mag). As of the 29th of December,
OVPF scientists observed during a fieldwork the small lava pond
which remained active with few lava ejection above the cone.
Following an active episode during the past week-end with about
10 visible lava flows on the talus and some outpouring on the
flow within the Dolomieu, the situation changed on Monday.
Except from the active cone, no other glowing lava could be
observed. Degassing remained relatively important, time to time,
the Dolomieu was filled with bluish gaz emission. As of the 26th
of December in the morning (9am), OVPF reported that eruptive
tremor increased again (3 time more compared at the beginning of
the eruption), but remained fluctuating. Following a fieldwork
during the afternoon of 24th of December, volcanologist reported
(5pm) that a small active lava pond formed within the small cone
in the Dolomieu. Time to time, lava fountaining occurs. Many
small lava flows are issued from small lava tubes around the
main lava flow. GPS measurements did not showed inflation or
deflation at the summit. OnThursday 18th of December, in the
evening, the eruptive tremor increased but this day returned at
the previous level, the same at the beginning of the eruption.
As of the 17th of december SO2 output was estimated at about
1000 Tons/day. As of the 15th of december, OVPF reported that
following a seismic crisis during Sunday (more than several
hundred earthquakes), and an important seismicity during the
night, a volcanic tremor, located beneath the summit, started at
2:45 am. An inspection carried out on 15th in the morning showed
that two eruptive fissures were active within the Dolomieu
crater, at half slope NNE and NE. The lava flow rate is very
weak; the lava covered only 15-20% of the September 2008 lava.
Also the SO2 output was very low. As of the 28th of November,
OVPF reported that the volcanic tremor declined since the early
morning, suggesting that the eruption was declining, with a
phenomenon ‘Gaz Piston' (important gas bubbles with very few or
not magma emission) making its appearence in the seismic record.
From 2pm ( local time) "gas piston" phenomenon ended and this
short eruptive phase ended. No seismic signal was recorded since
this time. As of the 27th of November, according to a report of
the OVPf, following a short seismic crisis between 1125am et
1140am, the volcanic tremor started at 1150am (local time). From
the tremor map, this new eruption occured within the Dolomieu
crater, probably at the same place of the previous activity
during October 2008. A volcanic plume was visible in the West
part of the Dolomieu.
As of the
31st of October, a new OVPF Buletin reported that during the
previous night a new seismic crisis occured between 4am and
440am with about 100 earthquakes accompanied with weak ground
deformation recorded by the tiltmeter network. As of the 22nd of
October, OVPF reported that 11 summital earthquakes were
recorded this day (max. magnitude1,2). No deformation occured.
As of the 20th of october, OVPF reported that in the morning,
between 8AM et 10AM, a new seismic crisis occured. No other
event was noted for the moment. As of the 17th of October OVPF
reported that since 3 days ago seismic activity increased. This
activity increased more on 16th of October beetween 630PM and
830PM (51 earthquakes) then re-decreased. Repartition of the
earthquakes : 14th of October: 62 ; 15th of October: 59 ; 16th
of October: 166; No long-term inflation was recorded for the
moment. Previous activity : as of the 2nd of October OVPF
reported that eruptive activity within the Dolomieu ended in the
early morning. The tremor dropped from 410AM and totally
disapeared at 445 AM (local time). Only a very weak deflation
has been recorded during the eruption and for this reason, it's
possible that other eruptive episode could occurs in the short
term (days or weeks). Total lave volume of the eruption is about
850.000 m3 for 10 days of activity.As of the 27th of September
OVPF reported that eruptive activity was still continuing in the
Dolomieu. Volcanic tremor remained stable at a low level since
the 26 september in the morning. Three summit low intensity
earthquakes were recorded. No direct observation was possible
due to the poor meteorological condition. Wednesday estimation
of the size and volume with an aerial photography showed that
the lava surface on the Dolomieu floor was about 180x100m (24
September in the morning) and a maximal thickness of 30m. The
present volume has been estimated at about 300 000m3, an flow
rate is 1m3/sec. As of the 21st of September, a special bulletin
of the OVPF reported that following a short seismic crisis
(about 10 earthquakes) a volcanic tremor appeared and the
eruption started at about 330 PM. This new eruption occured in
the West part of the Dolomieu (half hight) under the Bory
crater. Several lava flows went down toward the floor of the
Dolomieu and formed a small lava pond. As of the 17th of
September , ovpf reported that important seismic activity is
still continuing with 48 earthquakes recorded this day ( 41 with
mag. < 1,0 , 5 with mag. between 1,0 et 1,5 and 2 with mag.
between 1,5 et 2,0) . Field observations confirmed an increase
in degassing from the SW part of Dolomieu crater and the
presence of hydrogen sulfide. Another seismic crisis was
detected during 15-16 September. Numerous landslides followed
the crisis, but may have also been associated with heavy rains.
The Alert Level was not changed. As of the 12th of September, a
preliminary bulletin from OVPF reported that since 1015AM (local
time) this morning volcanic tremor started at the volcano and
stayed until 1130AM. The tremor (weak and variable) is located
beneath the summit of Dolomieu. According to an aerial
observation during the end of the morning, no eruptive activity
occured yet, but important SO2 emissions were noted. Another
trémor (more high frequency) occured in the afternoon at 350 PM,
but stopped around 8PM. During the day of the 12th of September,
30 earthquakes were recorded with a maximal magnitude = 1,6.
According to OVPF scientists an eruption could be occurs within
days or weeks. Alert level remains 1. As of the 9th of
September, OVPF reported that an important seismic crisis
occured during the night between 1123PM and 120 AM characterized
by several hundred eartquakes. No deformation was recorded. On
3rd of September, 76 earthquakes were already recorded with a
maximum magnitude 2.9 and 3.0. As of the 15th of August,
OVPFalready reported that a seismic crisis (2h35 duration)
occured this day between 5AM (local time) and 735AM (local
time). This short crisis was accompanied with ground deformation
in the Dolomieu area. At 10am, some superficial isolated
earthquakes (about 500 m a.s.l.) still occured. Previously on
4th of August another short seismic crisis (10mn) already
occured. Previous activity : as of 21st of June 2007, OVPF
reported that from one week many earthquakes occured every day
beneath the volcano (sometimes more than 100 per day). several
of them occured under the sea. As of 21st of June, maximal
magnitude was 2.6. As of the 2nd of May the Observatoire
Volcanologique du Piton de la Fournaise, IPGP, reported that
after one month of very high activity, the eruption at Piton de
la Fournaise, which started on April 2nd in the Grand Brûlé at
650 m altitude, finally stopped on May 1st. The debit at certain
moments was estimated between 100 and 200 m3 per second and the
lava flows covered an area of about 4 km2, with up to 30 or 40 m
thick lava. A platform of about 35000 m2 was build on the sea
and first estimations of the erupted volume amount to 120 x 106
m3 , which ranges this eruption between one of the largest known
historical eruptions at Piton de la Fournaise. As of the 27th of
April the OVPF reported that the seismicity under the summit was
reinforced. There were 50 seismic events the day before and the
lava flows remained very abundant in the Grande Brulé. As of
21st of April, the latest OVPF report informed the the volcanic
tremor remained at the same low level. Lava flows were still
went down in the Grand Brulé from the vent located to 650 m
elevation with important variations. As of the 20th of April the
Observatoire Volcanologique du Piton de la Fournaise, IPGP that
the collapse of Dolomieu crater was continuing. The tremor was
on a very low level, the seismics under the summit of the Piton
of Fournaise persisted. As of the 12th of April the Observatoire
Volcanologique du Piton de la Fournaise, IPGP reported that
members of the PC of St. Philippe observed two lava flows, the
first going along the rampart, a second in the medium of cast in
place, arriving at the sea. The inhabitants of the small village
of Tremblet breathe better, the situation finally seems to still
be improving. The crater which broke down on a 300 m height
stabilizes slowly. As of the 7th of April, OVPF reported that
following a fligh over the volcano on the morning, observation
showed that a large part ot the Dolomieu crater floor collapsed
on a surface estimated to 1000 x 700 m and a depth of about 300
m. The activity seismic remained at high level and many local
collapse occurs. As of the 6th of April the OVPF, reported that
the eruption at Piton de la Fournaise volcano continues and
eruptive activity, lava fountains and lava flow emissions from
the fissure vent at 600-500 m elevation, increases. Lava flows
had already crossed the National Road in the afternoon of 2
April and the southernmost of the 3 principal lava flow branches
reached the sea in the evening the same day. After decreasing
for a while, an unusual increase in seismic activity has been
observed since 3 April. It is marked by earthquakes below the
summit of the volcano at altitudes between 0 and 500 m above sea
level, similar to the ones registered before the opening of the
fissure on 30 March SE of the summit. They are interpreted as
consequence of internal collapse phenomena and might be
preceding a collapse event similar or stronger than the one in
1986 when a 100 m deep pit crater was formed. At the same time,
tremor (thought to be caused by the erupting magma moving along
the conduit and the radial dike) has increased as well,
accompanied by increasing visual effusive activity. In addition,
a marked increase in sulphur dioxide emission has been noted.
Inhabitants in the nearby city of St. Pierre have been suffering
from "vog" - volcanic smog caused by clouds of aerosols rich in
sulphur dioxide (SO2) emitted mainly at the eruptive vent and
from the lava flows. Several people have been brought to
hospital for treatment of skin and eye irriations as well as
asthma caused by the gas whose concentration temporarily reached
alarming levels, triggering the autorities to issue a general
health warning for the island. Reports of a new eruptive fissure
near the Pointe du Tremblet with its inhabited centres in the
lower areas just outside of the Enclos turned out to be wrong.
However, but scientists from the observatory don't exclude the
possibility that a new fissure could open up at even lower
elevation. Preparations for an emergency evacuation of this area
have started since late of 4th of April. Access to the summit
area of the volcano and the low elevation area near the lava
flows from the side of St. Pierre has been restricted by
authorities. As of the 2nd of April, OVPDLF reported that a new
eruption started at 10 AM. A new eruptive fissure opened in the
Southeast part of the enclos; the lower part of the fissure is
located at 500 m a.s.l at the foot of the Rempart du Tremblet.
The 1 km long eruptive fissure trend NO-SE- During the morning
lava fountaining (50 m high) occured from the fissure.
Associated lava flows went down fastly and about 2 PM the front
was at 300 m of the RN2. On Wednesday 3rd of April eruption was
still continuing. Lava flows crossed the road RN2 during the
afternoon. As of 30th of March, OVPDLF reported that following a
seismic crisis and deformation of the summit zone, a new
eruption started on 30th of March ( 23 PM - local time) on the
South-East flank of the volcano within the Enclos close to the
Chateau Fort area. This short erutive phase ended on 31st of
March at about 8 AM in the morning. (from OVPF-IPGP report) from
OVPF-IPGP - (Thomas Staudacher, OVVPF) -(OVPF information
d'après
Journal de l'île de la Réunion - ).
Live webcam -
IPGP
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COMOROS
- Karthala volcano
January
20th, 2007
As of 19th
of January, Volcano observatory reported that on Thursday 18th
the volcano shook twice again and local volcanologists said
there was still a threat of eruption despite the tremor seems
weakening. Comoros authorities have made emergency plan to help
as many 30.000 people in case of eruption. As of 13th of
January, volcano observatory reported that Mount Karthala
(2631m) begun emitting fumes and producing a red glow over the
tops. According to the chief geologist, the volcano has become
eruptive since yesterday evening 12th of January. The lava level
had risen in the volcano's crater. Preliminary information
reported that residents of Mvurni, a town at 1000 m altitude on
the volcano West slope were broken up by strong fumes. The
island had been on red alert. The last big eruption of the
volcano occured in April 2005, sent thousands fleeing in fear
poisonous gas and lava. The worst disaster on record came in
1903, when 17 died from noxious fumes that seeped from cracks.
The southernmost and largest of the two shield volcanoes forming
Grand Comore Island (also known as Ngazidja Island), Karthala
contains a 3 x 4 km summit caldera generated by repeated
collapse
.***********************************************************************************************************
TANZANIE - Lengai volcano
February 22nd, 2010
As of the
22nd of February GNN/GVP reported that periodic eruptions from a
small fissure and steam emissions from an area of the crater rim
next to a part that had collapsed were observed on 11 February,
and three fresh black hornitos were noted on the W part of the
crater floor, a cone-shaped grey hornito in the middle of the
floor and a new black lava flow to the S were seen during 14-15
February. Previous Informations : June-August 2009: a few
reports received during the summer, including ones documenting
visits in August by Thomas Holden , in July by David Gregson ,
and in June by Tobias Fischer , indicate that Lengai continues
to produce small effusive eruptions within the pit crater.
Thomas Holden reported that on his climb in late August (exact
date unknown) he saw active lava flows. Tobias Fischer witnessed
flows and a small lava lake ~5m in diameter in June. David
Gregson did not see significant activity but heard sounds of
activity at depth. Although the activity appears to have
returned to the typical eruptions of fluid natrocarbonatite lava
for which Lengai is so well known, no samples of the new flows
have been obtained for analysis due to their inaccessability
deep inside the pit crater. It is not known how similar the new
lava is in composition to the lavas produced prior to the
2007-2008 eruption. (From Fred Belton website)
Previous information : qccording to Frederick Belton team which
climbed Ol Doinyo Lengai on 18 June 2009reported that the new
active cone covered the former crater floor entirely except for
an area N of the summit. The new cone's W, N, and E sides stood
about 30 m above the rim of the former crater and enclosed a
deep crater. The visitors saw a few small vents on the crater's
floor. Frequent emissions of ash-poor plumes originated from the
SW part of the crater's floor, producing light ashfall. They
heard continuous loud rumbling noises, occasional gas-jetting
sounds, and rockfalls. As of the 21st of February, the Global
Volcanism Network (GVN) reported that Ol Doinyo Lengai volcano
in Tanzania erupted on 19th of February, according to an
aviation report. Ash was observed to 38,000 ft. Pilots have been
advised to avoid flying near the volcano. The activity at Lengai
seems to be increasing. In the past two weeks, explosions have
ejected ash plumes rising several kilometers. On 15 Feb., Dutch
pilots observed and photographed an eruption plume rising to
estimated 12 km (36,000 ft). The Toulouse VAAC reported that an
ash plume from Ol Doinyo Lengai was observed by pilots on 15
February and rose to an altitude of 11.6 km (38,000 ft) a.s.l.
As of the 24th of January, the Global Volcanism Network (GVN)
has reported that a visitor to Ol Doinyo Lengai informed that it
erupted on 14 January. According to this visitor "shower of
stones" fell at their location about 50 m from the summit and a
lava flow went another direction. Typical ash eruption from the
new ash cone in the N crater. A small group from Volcano
Discovery , local mountain guides and partners stayed near and
on Lengai volcano during 17-21 January. During this period,
Lengai continued to erupt ash to several 100 metres above the
new ash cone during phases lasting several hours alternating
with periods of quiet when only a weak plume of very fine gray
ash and gas was issuing out of the new ash cone. Photos from an
eruptive phase of Ol Doinyo Lengai volcano consisting in near
continuous ash emissions from its new crater and taken from the
summit during a recent expedition in January 2008 have been
posted at the Discovery:
http://www.volcanodiscovery.com/volcano-tours/photos/lengai/0108.html
. These photos also document the impressive recent changes
on the volcano and help to illustrate the significant hazards
present when climbing Lengai or staying at its top. The Toulouse
VAAC reported previously that an ash plume from Ol Doinyo Lengai
was observed by visiting scientists on 20 December and rose to
an unreported altitude. As of the 20th of October, John Seach
has reported that a pilot report indicated an eruption of Ol
Doinyo Lengai volcano in Tanzania occurred at 0830hrs local time
today. An ash plume reached 25,000 ft. altitude, and was visible
from a distance of 50 miles. The eruption lasted 30 minutes. As
of the 7th of September, according to Matthieu Kervyn De
Meerendre, University of Gent (Belgium) has reported that Ol
Doinyo Lengai has re-erupted again. A large eruption (?) seems
to be taking place at Lengai volcano, this time for real On 4
September 2007, reports started coming in that a large
(natrocarbonatite) lava flow is descending the West flank. A
considerable ash plume was visible on satellite data. Over 30
thermal anomalies have been detected by the MODIS team since
August 23 - more than during the large eruption in March 2006.
On 4 and 5 Sep, the thermal anomaly at the summit was extremely
strong. From this and satellite imaginery, it seems that there
was a short overflow to the East and a major overflow to the
West starting on September 1st (it could be a bush fire on the
volcano flank ignited by lava). New overflows on 5 Sep seem to
be taking place on the W and NW flanks. The symmetrical Ol
Doinyo Lengai stratovolcano is the only volcano known to have
erupted carbonatite tephras and lavas in historical time. The
prominent volcano, known to the Maasai as "The Mountain of God,"
rises abruptly above the broad plain south of Lake Natron in the
Gregory Rift Valley. The depth and morphology of the northern
crater have changed dramatically during the course of historical
eruptions, ranging from steep craters walls about 200 m deep in
the mid-20th century to shallow platforms mostly filling the
crater. Long-term lava effusion in the summit crater beginning
in 1983 had by the turn of the century mostly filled the
northern crater; by late 1998 lava had begun overflowing the
crater rim.
*********************************************************************************************************
CONGO -
Nyamulagira volcano
February 4th, 2010
During 27
January-2 February, the MODIS sensor aboard the Earth Observing
System (EOS) satellite frequently detected thermal anomalies
from Nyamuragira. The Toulouse VAAC reported that a diffuse ash
plume was seen on satellite imagery on 29 January. As of the
18th of January latest news reported that the eruption of
Nyamuragira volcano in the Democratic Republic of Congo that
began two weeks ago seems continuing according to satellite
data. The availability of MODIS hotspot data is affected by
cloud cover, which has been considerable in the area of the
volcano over recent days. However, MODIS images for 13 and 15
January shows the thermal signatures of fresh lava emissions to
the east and south of Nyamuragira's summit crater. The volcano
has also been emitting considerable quantities of sulphur
dioxide, as shown by OMI SO2 data. Significant SO2 clouds were
detectedon 13 and 17 January 2010. As of the 11th of January,
the previous information on the eruption from Samantha Newport,
director of communications for Virunga National Park, reported
that lava fountains were reaching almost 300 metres in height on
Saturday 9 January, but that volcanic activity had since
diminished. The decline in activity appears to be confirmed by
the fact that no thermal hotspots have been detected by Modis at
Nyamuragira since 8 January 2010. As of the 7th of January, five
days after it began the eruption of Nyamuragira volcano in the
Democratic Republic of Congo is continuing, with fire fountains
and very liquid and free-flowing lava. The flows are directed
towards the south-west. Information from the UN reported that
the advance of the lava has slowed, with only 100 metres of
advance in the last 24 hours, not because the eruption rate has
slowed – the activity of the volcano remains intense – but
because the lava front has widened from 15 metres to about 200
metres. As of the 5th of January GVO reported that the eruption
which began early on 2 of january was continuing and seems to be
increasing in intensity, raising concerns about local human and
animal populations. Lava flows are causing forest firesaround
the volcano and some reports say nearby villages are threatened
by the eruption. The United Nations is providing aircraft to
help the local authorities monitor the eruption. As of the 2nd
of January 2010, according to a government official the
Nyamulagira volcano erupted sending lava toward a national park
on Saturday at dawn. While the area where the lava was headed is
sparsely populated, wildlife officials say it is home to about
40 endangered chimpanzees. Government observers are monitoring
the situation with help from U.N. helicopters. The director of
Virunga National Park says the eruption is "of great concern"
and that rangers have been deployed to monitor the lava flow.
Further details as soon as possible. Africa's most active
volcano, Nyamuragira (Also spelled Nyamulagira) is a massive
basaltic shield volcano N of Lake Kivu and NW of Nyiragongo
volcano. Lava flows from Nyamuragira cover 1,500 sq km of the
East African Rift. The 3058-m-high summit is truncated by a
small 2 x 2.3 km summit caldera that has walls up to about 100 m
high. About 40 historical eruptions have occurred since the
mid-19th century within the summit caldera and from numerous
fissures and cinder cones on the volcano's flanks. A lava lake
in the summit crater, active since at least 1921, drained in
1938. Twentieth-century flank lava flows extend more than 30 km
from the summit, reaching as far as Lake Kivu.
CONGO - Nyiragongo
February 4th, 2010
During 27
January-2 February, the MODIS sensor aboard the Earth Observing
System (EOS) satellite continued to frequently detect thermal
anomalies from Nyiragongo, likely from lava lake activity. Based
on analyses of satellite imagery, the Toulouse VAAC reported
that during 30-31 January a diffuse plume drifted 240 km W. One
of Africa's most notable volcanoes, Nyiragongo contained an
active lava lake in its deep summit crater that drained
catastrophically through its outer flanks in 1977. In contrast
to the low profile of its neighboring shield volcano,
Nyamuragira, Nyiragongo displays the steep slopes of a
stratovolcano. Benches in the steep-walled, 1.2-km-wide summit
crater mark the levels of former lava lakes, which have been
observed since the late 19th century. About 100 parasitic cones
are located on the volcano's flanks and along a NE-SW zone
extending as far as Lake Kivu. Monitoring is done from a small
observatory building located in Goma, ~18 km S of the Nyiragongo
crater. (From GVO)
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ETHIOPIA - Manda Hararo area
July 24, 2009
As of the
16th of July, the Global Volcanism Network (GVN) has reported
that a large sulfur dioxide plume and several thermal anomalies
from Manda Hararo that were detected in satellite imagery during
28-30 June prompted a science team to visit the area on 4 July.
After conducting ground-based and aerial observations for
approximately 2 hours, they reported that the eruption occurred
near the August 2007 eruption site, and was possibly bigger than
that event. No active lava effusion was seen, but steaming was
observed from the 4-5 km-long fissure that, because of high
temperatures, had to be observed from a distance. They also saw
new predominantly 'a'a lava flows that were 2-3 m thick. The
fissure was lined with scoria ramparts 30-50 m high. Temperature
measurements taken with a FLIR (Forward Looking Infrared
Radiometer) indicated that the lava flow had cooled
significantly with temperatures between 30 and 120 degrees
Celsius at the surface. A maximum temperature of 238 degrees
Celsius was measured during aerial observations. Thermal
anomalies and dense sulphur dioxide plumes in Ethiopia appear to
indicate that a significant effusive eruption has taken place
along the Karbahi graben at or near Manda Hararo fissure vents.
There is as yet no visual confirmation of the eruption from the
ground. The Modis thermal alert service at the University of
Hawaii has shown hotspots of varying intensity over a
considerable area of the Manda Hararo region since 27 June,
while the OMI dioxyde sulfur group has mapped considerable SO2
emissions on 29 and 30 June. MODIS thermal anomaly indicating
surface lava flows. Preliminary analysis (based on SO2
emissions) suggests that it is larger than the Manda Hararo
eruption in August 2007, but not as large as the Alu-Dalaffilla
eruption last November. On the MODVOLC
thermal alerts website the interface allows one to zoom in
at specified coordinates. Entering those for Manda-Hararo
(40.8E, 12.2N; degrees and decimal degrees) show a series of
alerts spread over considerable area for as late as 30 June
2009. Going back in time, there appeared a large intense cluster
(29 June), a less intense cluster (28-27 June), and then no hits
on earlier days. A map appears in Volcanoes of the World, with
comparatively few volcanoes identified surrounding Manda Hararo
(Haroro Manda). The 2007 Bulletin report on that volcano
contains a map of the area (BGVN 32:07) From Rick Wunderman
GVN/GVP.
ETHIOPIA - Alu volcano area (or Dalafilla)
November 25th , 2008
During
19-24 November, the MODIS satellite continued to detect thermal
anomalies over the area near Dalaffilla and Alu volcanoes from
the eruption that began on 3 November.On 16 November the ASTER
(Advanced Spaceborne Thermal Emission and Reflection Radiometer)
equipment aboard NASA's Terra satellite acquired the area of
north-east Ethiopia where the volcanic eruption took place on 3
November 2008. The ASTER data provides the clearest imagery made
available to date. On the evidence of these new images it is the
Alu fissure vent zone, rather than Dalaffilla volcano, which is
responsible for the current eruption.
A new, large
dark lava flow is evident, covering a large area and extending
about 12km north-east of the Alu vents. The lava flow produced
by this eruption covers a large area and overlies
previously-deposited flows. As of the 15th of November, Modis
instrument reported that hotspots continue to be measured
between Dalaffilla and Alu volcanoes in Ethiopia. This indicates
continued lava flows following last weeks eruption of
Dalaffilla-Alu volcano. Satellite images show sulphur dioxide
emissions over north Indian Ocean and central India. As of the
8th of November, the Global Volcanism Netork (GVN) has reported
that now there is some debate over exactly which volcano erupted
in Ethiopia this week. Satellite images show that a large lava
flow originated from a region between Dalaffilla and Alu
volcanoes in the Erta Ale Range. Alu and Dalaffilla are twin
volcanoes separated by only 3 km. Alu volcano is ellipsoidal in
shape, and built of old basaltic lavas. In contrast Dalaffilla
is a steep cone built by eruptions of silicic lava. Some reports
have assumed this week's large lava flow must have come from Alu
volcano bacause it has produced basaltic lava flows before.
However, satellite images have shown lava hotspots on the side
of Dalaffilla volcano. Dalaffilla volcano as the source of the
lava flows was declared by a researcher at Addis Ababa
University. The summary is that an eruption of lava began at at
Dalaffilla volcano in the Afar range of Ethiopia on Tuesday 4th
November (?). According to recent news articles, observers
reported ground shaking, hearing loud noises and explosions from
a distance, and seeing smoke. Thermal anomalies continued to be
detected during 3-6 November in the area. Primary information :
satellite instruments detected an eruption in northern Afar,
Ethiopia from November 3. The eruption first manifested itself
as a large sulfur dioxide (SO2) cloud drifting eastwards over
the Arabian peninsula, detected by the Ozone Monitoring
Instrument (OMI) and the Atmospheric Infrared Sounder (AIRS).
MODIS data from the University of Hawaii's MODVOLC hot-spot
monitoring tool (http://modis.higp.hawaii.edu)
confirmed an extensive hot-spot (presumably lava flows) near Alu
volcano ( or Dallafilla ?), in the northern part of the Erta
‘Ale range. Details are still sketchy and these observations are
as yet unconfirmed from the ground. Addis Ababa University's
Institute of Geophysics researchers said on Wednesday, prompting
a minor earthquake and record lava flows covering 300 square
kilometres. Satellite pictures also showed that the volcano area
covered a record area of 300 square kilometres, According to the
ethiopian institute no major damage to infrastructure or
population displacement were immediately reported. A total of
0.1-0.2 Tg of SO2 was measured in the eruption cloud by OMI at
~1100 UT on November 4, by which time the SO2 cloud had reached
southern Iran. Using the OMI SO2 data and radiosonde soundings,
observed SO2 cloud drift yields a preliminary estimate of the
eruption onset time of 1400-1600 UT on November 3. Near
real-time OMI SO2 data can be viewed at:
http://satepsanone.nesdis.noaa.gov/pub/OMI/OMISO2/index.html
. The summit region of Alu volcano, lying immediately NW of
conical Dalaffilla volcano, is an ellipsoidal volcanic horst,
elongated in a NNW-SSE direction, and formed primarily of older
basaltic lava flows. Very recent fractures along the axis of the
chain cut the main volcanic horst. Major fumarolic activity is
located on the numerous parallel faults, some of which have
uplifts of 100 m. Fissure vents west of the horst have fed
silicic lava flows, and other fissures to the south have
produced voluminous youthful basaltic lava flows that extend
north as far as Lake Baki. Dalaffilla, also referred to as
Gabuli, is a small, but steep-sided conical stratovolcano that
rises 300 m above surrounding lava fields SE of Alu volcano.
This morphology, unusual for the Erta Ale Range volcanoes,
results from the extrusion of viscous, silicic lava flows with
primary slopes up to about 35 degrees. These silicic flows
extend primarily to the east; on the west they are blocked by
walls of a horst structure along the crest of the Erta Ale
range. Other basaltic lava flows from regional fissures surround
the 613-m-high volcano. Fumarolic activity occurs in the
100-m-wide summit crater and has weathered surrounding lava
flows.
ETHIOPIA - Erta Ale volcano
March
6th, 2010
As of the
5th of March 2010, according to Rafael Werndli reports an
unusually hight lava level in the pit crater on Erta Ale in mid
February 2010. The lake surface was approximately 20m below the
pit's edge. The lava lake had a diameter of 100 to 110m.
Occesional floodings of the uppermost terrace were observed. In
addition a hornito was active in the north crater, ejecting
scoriae and small lava flows. PREVIOUS INFORMATION AND REPORTS :
As of the 20th of February 2008, the Stromboli-On-Line website
has reported that upon their return to volcano Erta Ale, they
found it to be in eruption on the 8th of February and have
confirmed this information. Volcanologique de Geneve (SVG) trip
on 8-9 February 2008 noted extensions of ropy lava in the N
crater. The lake was little changed from the group's last visit
in 2005. The group visited the N Crater, and, given its constant
degassing, was able to take gas samples. They also measured the
lake's surface temperature (700°C). The descent into this
crater, seemingly easy, was made difficult by a mantle of very
unstable lava scoria. An elevated level of the lava lake halted
a subsequent descent.Previous information reported that on 7th
of October 2005, according to Ethiopian newspaper an earthquake
measuring 4.2 on the Richter scale, jolted northern Ethiopia
(Teru area in Afar) on Tuesday triggering eruption of the Erta
Ale. According to M; Manahlo Belachew, an expert in the
seismology department of Addis Ababa University, the quake which
strick the remote region afar is the 11th tremblor to rumble
across the region since last month. As of 5th of October a hot
spot was visible on the Erta Ale from the MODIS images which
could confirmed an eruptive activty this day. Previous new
report about recent activity of the Erta Ale : group of
scientists assessed the visible changes at Erta Ale on 26
September after activity began around 24 September. In
comparison to observations made in November 2004, they found
that the southern main crater/pit had widened significantly,
with portions of the previous crater walls having collapsed into
the lava lake. A new cone-shaped construct had grown within the
southern main crater where there had been a platform. A lava
lake occupied the entire width of the inner crater/pit. In the
northern crater/pit, there was a solidified lava bulge and
abundant “smoking” along the crater walls. No incandescent lava
was visible in the pit. Based on descriptions by local residents
of seeing “red and glowing light shooting and rising into the
air above the volcano,” the scientists believe that a
Strombolian eruption probably occurred, emitting a significant
volume of fresh magma within, and possibly out of, the pit. As
of 4th of 0ctober, Personal source reported from Addis Ababa
University that the recent earthquake that occured in Afar state
has caused landslide and big fissure in Teru locality kebele 02
of the state near the active volcano Mount Erta Ale, a team of
geologists who have just returned from the site disclosed. The
earthquake observed from September 10 -24, 2005 is the
culmination of volcanic activities in the area since millions of
years ago, geologists Dr. Derge Ayalew and Dr. Gezahegn Yirgu
told WIC. The geologists said the landslide and fissure are
indicators that there would be a possible volcanic eruption in
the future. The Physical Observatory of the Addis Ababa
University recorded on Sunday earthquake that measured 5.5 on
Richter scale following earthquake. In Erta Ale the volume of
material inside the Crater is actually increasing i.e. rising up
to the Crator rim. Due to all this recent geological activity
the government is starting to evacuate the people residing
around these areas. Previous Erta Ale visit : an international
team led by SVE carried out a new visit at the Erta Ale from
22nd of January to 23rd of January 2005. During these two full
days at the summit the eruptive activity showed no significant
change since our previous observation carried out in November
2005. Degassing activity was still occuring from 3 of the 4
coalescents hornitos located in the SW part of the South crater,
but decreased slightly in comparison with our December
observations. There were about 10 m high and represented the
only portion of the lava crust covering the crater floor where
gas emissions were in evidence. One of the hornitos contained
glowing molten lava visible from a window located in the upper
part. During the clear day of Sunday 23rd of January, members of
the team abseiled down within the crater to collect recent lava
poured out from the hornitos during partial collapse. Degassing
activity (mainly SO2) from the North crater has also slightly
decreased in comparison with early December 2004. From a small
terrace located in the NW part of the crater it was possible to
observe the degassing activity from several hornitos ( some of
them were several meters high in the central part of the " lava
bulge ") - Near the NW wall of the crater two small red glowing
areas were visible at the summit of two other hornitos. Seismic
activity of the volcano, together with infrasound signals were
recorded by a portable system of the University of Hamburg.
Preliminary results of this deployment will be reported soon at
this place. Informations : Henry Gaudru, SVE Geneva ;
Alexander Gerst , University of Hamburg, Germany ; Georges
Kourounis, Derek Tessier, Brian Fletcher (Toronto - Canada) ,
Motomaro Shirao (Tokyo- Japan) . A previous visit of the
SVE-SVG group (4th of December 2004) have permits to observe an
important change in the activity of the volcano. The lava lake
activity stopped within the South pit crater and a solidified
lava crust has filled the whole part of the crater floor (about
15 m below the crater rim). Three (4) coalescent hornitos (about
ten meters high) have built on the solidified lava crust in the
SE part of the South crater. During the night between 4th of 5th
of December, some incandescent degassing lava was visible at the
summit of two hornitos. Moreover, we have also noted that a new
activity has recently occured within the North crater. A
solidified lava bulge uplifted and filled more than 4/5 of the
crater floor (about 20-25 below the crater rim). Strong and
noisy degassing activity was occcuring in the central part of
the lava bulge from several small hornitos. From the smell and
bluish color, these gases contained a high quantity of SO2.
During the night , ten small incandescent vents were visible at
the periphery of the lava bulge. In the morning, two plumes rose
above the volcano. Information : Henry Gaudru (SVE) and Co (SVG)
-
Erta Ale report in case of problem with this link look
directly at "articles page"
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|
Piton de la Fournaise - Eruptive fissure - 16th
November 2002 - Photo Laï-Yu (JIR) |
|
|
PHILIPPINES - Mayon Volcano
March 5th,
2010
As of the
4th of March, the Philippine Institute of Volcanology and
Seismology (PHIVOLCS) has reported that there has been a
lowering of Mayon volcano's status from Alert Level 2 (evidence
of magmatic intrusion that could eventually lead to an eruption)
to Alert Level 1 (no hazardous eruption imminent). After the
alert status was lowered to Alert Level 2 last 13th of January,
Mayon volcano has consistently manifested the following: 1. The
number of volcanic earthquakes recorded daily (0 – 4 per day) is
well within the normal level for Mayon of 5 volcanic earthquakes
per day; 2. Volcanic tremors associated with magma movement
within the volcano conduit became scarce and sometimes not
recorded at all; 3. Ground deformation measurements showed a
deflated volcano edifice indicating the absence of fresh
volcanically-induced deformation or fresh supply of magma from
below; 4. The sulfur dioxide (SO 2 ) emission rate measured
since the 13th of January to March ranged from 110 to 2,021
tonnes per day (t/d) is consistent with its post eruptive gas
emission rate, and; 5. The observed crater glow prevailed at
intensity II (can be observed with the naked eye) but does not
indicate any re-intensification. Steam emission was most of the
time weak and passively rising from the summit crater. The above
observations suggest that Mayon volcano's condition is improving
and likely heading towards normalcy. In view therefor, PHIVOLCS
is now lowering its alert status from Alert Level 2 to Alert
Level 1, meaning that eruption is not imminent. The public,
however, is reminded that the 6-km radius Permanent Danger Zone
(PDZ) remains off-limits due to the continuing threat from
sudden small explosions and rock falls from the upper and middle
slopes of the volcano. Active river channels and those areas
perennially identified as lahar prone in the southeast sector
should also be avoided especially during bad weather conditions
or when there is heavy and prolonged rainfall. As of the 17th of
February, the Philippine Institute of Volcanology and Seismology
(PHIVOLCS) has reported that Mayon volcano's seismic monitoring
network detected two (2) volcanic earthquakes and eleven (11)
rockfall events were detected by the seismic network. The
seismic network recorded a total of twenty-six (267) volcanic
earthquakes and fifty-seven (57) rockfall events (01 - 07
February 2010). With respect to Ground Deformation deflation. No
change relative to 08-10 Nov. 2009 survey. Overall, the volcano
remained inflated by five (5.0) mm. cumulative to February 2008
baseline data SO 2 Flux Reading: 1667 tonnes/day (12 Feb.) but
otherwise at: 719 tonnes/day (11 Feb.), 425 tonnes/day (10 Feb.
), 447 tonnes/day (9 Feb.), 430 tonnes/day (8 Feb.). Steaming
activity was obscured and crater glow was at Intensity II As of
the 6th of February, PHIVOLCS reported that Mayon volcano's
seismic monitoring network detected five (5) volcanic
earthquakes and twelve (12) rockfall events were detected by the
seismic network. The seismic network recorded a total of
seventeen (17) volcanic earthquakes and sixty-nine (69) rockfall
events (18 - 24 January 2010). With respect to Ground
Deformation deflation. No change relative to 08-10 Nov. 2009
survey. Overall, the volcano remained inflated by five (5.0) mm.
cumulative to February 2008 baseline data SO 2 Flux Reading:
1687 tonnes/day (28 Jan.) but otherwise at: 868 tonnes/day (26
Jan.), 288 tonnes/day (25 Jan. ), 1076 tonnes/day (24 Jan.),
1001 tonnes/day (23 Jan.). Steaming activity was moderate and
crater glow was at Intensity II. As of the 15th of January, the
Philippine Institute of Volcanology and Seismology (PHIVOLCS)
has reported that Mayon Volcano's seismic network recorded 3
volcanic earthquakes and 13 rockfall events related to the
detachment of lava fragments at the volcano's upper slopes
during the past 24 hours. Steaming activity and crater glow were
not observed due to thick clouds that covered the summit crater.
Sulfur Dioxide (SO 2 ) emission rate was measured yesterday at
an average of 635 tonnes/day. As of the 12th of January,
PHIVOLCS reported that six (6) volcanic earthquakes and
seventeen (17) rockfall events related to the detachment of lava
fragments at the volcano's upper slopes were detected by seismic
monitoring network during the past 24 hours. Weak to moderate
emission of white steam at the summit crater was seen during
cloud breaks yesterday and early this morning. Pale crater glow
was still observed last night. Yesterday's measurement of Sulfur
Dioxide (SO2) emission rate yielded an average of 820 tons/day.
Results of ground deformation measurements at Buang and Lidong
precise leveling lines showed deflationary trend compared to 02
December 2009 survey. Alert Level 3 is still in effect over
Mayon Volcano. As of the 5th of January, PHIVOLCS reported that
three (3) volcanic earthquakes and twenty one (21) rockfall
events related to the detachment of lava fragments at the
volcano's upper slopes were detected by seismic monitoring
network during the past 24 hours. Steaming activity and crater
glow were not observed due to thick clouds that covered the
summit crater. Sulfur Dioxide (SO 2 ) measurement was not
conducted yesterday due to rain that occurred over the volcano
area. As of the 4th of January, PHIVOLCS reported that seismic
monitoring network detected 7 volcanic earthquakes and 33
rockfall events related to the detachment of lava fragments at
the volcano's upper slopes. Steaming activity was not observed
due to thick clouds that covered the summit crater. Pale crater
glow was observed last night. Sulfur Dioxide (SO 2 ) measurement
was not conducted yesterday due to rain that occurred over the
volcano area. As of the 2nd of January 2010, PHIVOLCS reported
that the seismic monitoring network around the volcano detected
13 volcanic earthquakes and 68 rockfall events related to the
detachment of lava fragments at the volcano's upper slopes
during the past observation period. Emission of weak volume of
white steam at the summit crater was observed during cloud
breaks yesterday. Sulfur Dioxide (SO 2 ) emission rate was
measured yesterday morning at an average value of 2,621
tonnes/day. The latest activity of Mayon still indicates that
its overall state of unrest remains relatively high. However,
this phase of unrest, characterized by moderate seismicity, high
volcanic gas outputs and continuing glow of the summit are
processes normally associated with very gradual return to the
repose period. The volcanic system is expected to continue
producing earthquakes and to vent a large amount of gases
because fresh magma still resides along the whole length of the
volcanic pipe and near the summit. From 28 December to present,
a declining trend in Mayon volcano's activity was noted as
reflected by the following observations: 1. No ash ejections
were observed since 29 December. Steam emission was most of the
time weak and white in color indicating considerable decrease in
energy and absence of ash. 2. Majority of the type of
earthquakes that were recorded during the past days were
associated with rockfalls and rolling down of fragments from the
lava deposits along Bonga gully and the advancing lava front. 3.
Measured SO 2 levels have also showed a decreasing trend from a
maximum of 8,993 tons per day to 2,621 tons per day. The still
high concentration of SO 2 gas emission suggests that there is
residual magma degassing at shallow depth. In view of the above
observations, PHIVOLCS-DOST is lowering the alert status of
Mayon from Alert Level 4 to Alert Level 3 to reflect the overall
gradual decrease of activity. Previously, As of the 30th of
December, PHIVOLCS reported that for the past 24 hours, one ash
explosion occurred at Mayon Volcano (13.2576 N, 123.6856 E). The
explosion produced a dirty white ash column that rose to about
100 meters above the summit and drifted to the northwest. Lava
continued to flow down along the Bonga-Buyuan, Miisi and Lidong
gullies. The lava front has now reached about 5.9 kilometers
from the summit along the Bonga-Buyuan gully. Mayon Volcano's
seismic network recorded 16 volcanic earthquakes. A total of 150
rock fall events related to the detachment of lava fragments at
the volcano's upper slopes was also detected by the seismic
network. Yesterday's measurement of Sulfur Dioxide (SO 2 )
emission rate yielded an average value of 4,397 tonnes per day
(t/d). The volcano edifice remains inflated as indicated by the
electronic tilt meter installed at the northeast sector of the
volcano. As of the 25th of December,PHIVOLCS reported that Mayon
Volcano continued to show an intense level of activity during
the previous 24-hour observation period. Ninety-six (96) ash
explosions were observed during times of good visibility. These
explosions produced light brown to grayish ash columns that
reached heights of up to 2 km. One hundred twenty five (125)
rumbling and booming sounds from the volcano were heard at the
Lignon Hill Observatory in Legaspi City . Seismic activity
remained elevated as the seismic network recorded a total of
eight hundred seventy one (871) volcanic earthquakes. Ninety
eight (98) rock fall events, related to detachment of lava
fragments at the volcano's upper slopes, were also detected.
Three of these events were observed to have generated
pyroclastic flows that moved down within 2 km from the crater.
Sulfur Dioxide (SO2) emission rate was high and was measured at
an average of 2,738 tonnes/day yesterday. As of the 23rd of
December, bulletin of PHIVOLCS reported that Mayon Volcano
continued to show an intense level of activity during the past
24-hour observation period. Seismic activity remained elevated
in number and size as the seismic network detected 1,051
volcanic earthquakes and continuously recorded harmonic tremors.
Many of these volcanic earthquakes were recorded at maximum
deflection. Sixty six (66) ash explosions were observed during
times of good visibility. These explosions produced grayish to
light brown ash columns that reached height from 100 to 1000
meters above the summit before drifting towards southwest.
Sulfur Dioxide (SO2) emission rate remained very high and was
measured at an average of 6,737 tons per day (t/d) yesterday.
Two hundred eighty (280) audible booming and rumbling sounds
were intermittently heard for the past 24 hours. Red hot lava
also continuously flowed down along the Bonga-Buyuan, Miisi and
Lidong gullies. As of the 21st of December, PHIVOLCS reports
that activity escalated during the past 24-hour observation
period. Seismic activity dramatically increased in number and
size. A total of 1,942 volcanic earthquakes was detected by the
seismic network. Many of these volcanic earthquakes were
recorded at maximum deflection and continually occurred
beginning at 12.21 yesterday. Harmonic tremors were also
continuously recorded. Sulfur Dioxide (SO2) emission rate
remained very high at 6,089 tonnes per day (t/d). Audible
booming and rumbling sounds were first reported in the eastern
flank of the volcano at about 1455H then occasionally occurred
beginning 2200H last night. Intensified crater glow and rolling
down of incandescent lava fragments from the crater was also
persistent. Red hot lava also continuously flowed down along the
Bonga-Buyuan, Miisi and Lidong gullies. Lava fountains rising
approximately 200 meters above the crater were observed at
2007H, 2008H and 2018H. The lava front has now reached about 5
kilometers downslope from the summit along the Bonga-Buyuan
gullies. Alert level is 4. As of the 19th of December, PHIVOLCS
reported that the volcano continued to exhibit intensified
activity for the past observation period. A total of one hundred
ninety seven (197) volcanic quakes and tremors were recorded by
the seismic network. Eighteen (18) of these events were
explosion type, however, only fifteen (15) were observed during
times of good visibility. These explosions produced dirty white
to grayish ash columns that reached height from 100 to 2000m
above the summit before drifting towards southwest. Harmonic
tremors were continuously recorded by the seismic instruments.
During cloud break this morning, steaming activity ranged from
dirty white to light brown in color. Night observation showed an
intensified crater glow and continuous rolling down of
incandescent materials from the crater. The advancing lava flow
has now reached approximately 4 kilometers downslope from the
crater along Bonga Gully. Sulfur Dioxide (SO2) emission
increased from 1,065 to 2,034 tonnes per day (t/d). As of the
17th of December, PHIVOLCS reports that two lava domes have
formed at the crater of the volcano, raising concerns among
government volcanologists over the possible extensive damage
should these collapse and a major eruption occur. Renato
Solidum, director of Phivolcs, said the domes were growing and
that an aerial survey must be conducted to determine the hazards
these would pose to residents living within the danger zone. As
of the 16th of December, PHIVOLCS reported that the volcano has
continued to erupt lava and ash as thousands of people are
evacuated from surrounding towns and villages. Phivolcs also
reported glowing lava fragments continually being ejected onto
the upper and middle slopes of the volcano. The head of disaster
relief for eastern Bicol region has reported that ash explosions
have reached heights of 1000 metres. Mandatory evacuations of
around 10,000 families from within Mayon's 6-8 km danger zone
have begun, with more than 20,000 people moved out so far.
Ultimately around 50,000 people may need to be evacuated. As of
the 15th of December, PHIVOLCS reported that after lava began
flowing from the crater earlier today, evacuations are under way
around the Mayon volcano. A number of small ash explosions took
place during the day, and the lava flows were reported from
around 18:00 local time. At 20:00 local time the Phivolcs raised
the alert level from 2 to 3. Mandatory evacuations of
communities within the 6-8 km danger zone around Mayon will
begin on Tuesday morning. Parts of the cities of Legazpi, Tabaco
and Ligao, and the towns of Daraga, Camalig, Guinobatan, Santo
Domingo, Bacacay, and Malilipot, fall within the danger zone:
many thousands of people will be affected by the evacuations.
Albay provincial authorities say that at least 9,000 families
will be evacuated. As of the 12th of December,PHIVOLCS reported
that a small ash eruption occured on the evening of Friday 11
December 2009. The eruption occured at around 19:59 local time,
and was preceded by rumbling sounds and about 50 earthquakes,
felt by people living in nearby villages. Ash was ejected to an
altitude of 0.5 km above the crater. As of the 3rd of December,
PHIVOLCS repored that the volcano was calm for a week, but on
Thursday shook and spat out sulfur dioxide. Instruments detected
18 volcanic quakes, of which eight were low and five were high-
frequency earthquakes, indicating that magma was climbing up the
volcano's vent. The volcano discharged 858 tons of sulfur
dioxide in the past 24 hours, or above the normal 500 tons
ejected by a restive volcano. Alert level 2 remains Mayon, a
2463-metre stratovolcano, is famous for the near-perfect
symmetry of its cone, as well as its ability to unleash
destructive eruptions, with hazards including pyroclastic flows,
lahars and heavy ashfall. Particularly violent eruptions causing
many deaths occurred in 1814 and 1897; more recently an eruption
in September 1984 caused no fatalities after warnings from
Philvolcs brought about the evacuation of more than 70,000
people from at-risk areas near the volcano. Information :
PHIVOLCS -
Latest satelllite image of the Mayon (every 30 mn)
PHILIPPINES - Taal volcano
August
30th, 2008
As of the
29th of August 2008, State PHIVOLCS scientists advised the
public to observe precautions when going near Taal Volcano in
Batangas, saying the volcano has shown an “increase in
seismicity." the Taal seismic network recorded 10 volcanic
earthquakes from 5:30 a.m. to 3 p.m. Thursday. Two of the quakes
that occurred at 12:33 p.m. and 12:46 p.m. were both felt at
Intensity II at Pira-piraso villages. Accompanying the quakes
were rumbling sounds. The events were located northeast of the
volcano island near Daang Kastila area with depths of
approximately 0.6 km (12:33 p.m.) and 0.8 km (12:46 p.m.).
Surface thermal observations however, did not indicate
significant change in the thermal and steam manifestations of
the Main Crater Lake area. The Philippine Institute of
Volcanology and Seismology (Phivolcs) reported that increase in
seismicity (frequency and distribution of earthquakes) reflects
a "low-level episode of unrest," and that Alert Level 1 remains
in effect there. At present, no imminent eruption is indicated
although the public is advised to observe some precautions.
Previously, past year, on June 24th , PHIVOLCS already reported
that Taal volcano showed signs of unrest when two volcanic
earthquakes were felt at Pira-Piraso village. According to local
people, this seismic unrest was accompanied by rumbling around
2:30 in the morning. A total of 8 volcanic earthquakes were
measured by PHIVOLCS seismographs. There was no change to the
alert status of the volcano. As of 18 th of December 2006,
PHIVOLCS reported that between 13-14 December, 10 volcanic
earthquakes were detected. Ground deformation surveys conducted
on 28 November-6 December 2006, revealed inflation of the
volcanic edifice by 14.0 mm, suggesting possible magma
intrusion. Taal volcano manifested a sustained moderate level of
seismic activity since 18 November 2006, characterized by
occasional large amplitude volcanic earthquakes. The main crater
lake water is becoming more acidic since 12 September 2006. the
newly formed mud geyser, which is now merged with the crater
lake due to increase in water level, continues to be very
active. The increasing acidity and hydrothermal activity are
probably caused by the injection of hot gases and fluids coming
from below the crater floor. As of the 22nd of November, the
PHIVOLCS was reported that tall volcano's main crater
(Northeastern part) was spewing three or five-meter-high geysers
of muddy water since the past Friday. Since, mud geysering has
continued, but the volcano stays at alert 1. A similar event,
which was recorded in November 1999, lasted until February 2000.
Previous report - As of the 5th of October, the Philippine
Institute of Volcanology and Seismology (PHIVOLCS) has reported
that the Taal Main Crater Seismic Station recorded twenty nine
(29) volcanic earthquakes during the past 24-hour period since
0600 yesterday. Five (5) of these quakes that occurred at 0233,
0234, 0242, 0247 and 0249 were felt at Intensities II to III by
residents on Volcano Island. These quakes were accompanied by
rumbling sounds. Initial earthquake locations showed epicenters
generally dispersed in the vicinity of Daang Kastila
(Northeast), Tibag (North), Tablas (Northeast), Mataas na Gulod
(Northeast) and Panikihan (Northwest). This seismic activity is
notably higher than the usual levels, which is generally only 5
or less events detected in 24 hours during quiet periods.
Surface thermal observations, however, did not indicate
significant change in the thermal and steam emission
manifestations of the Main Crater Lake area. The increase in
seismicity at Taal Volcano reflects a low-level episode of
unrest. However, there is still no indication of an impending
eruption. Possible precursors, such as increased steam emission,
increased temperatures of steam vents and other changes on the
Main Crater Lake waters and of the ground are continuously being
monitored. The ongoing seismic unrest could intensify in the
coming days or weeks so that PHIVOLCS recommends appropriate
vigilance by the public when visiting the island. As a safety
measure, PHIVOLCS reiterates its previous recommendation that
the Main Crater area remains off-limits because sudden steam
explosions may occur or high concentrations of toxic gases may
accumulate. There are also several fissures traversing the Daang
Kastila Trail which, when reactivated with steam emission, are
also potentially hazardous to people. PHIVOLCS will provide
information on the status of Taal Volcano as necessary. The
colour code at Taal is currently at YELLOW . PHIVOLCS will
provide information on the status of Taal Volcano as necessary.
PHILIPPINES - Kanlaon volcano
September 5th, 2009
As of the
4th of September, the Philippine Institute of Volcanology and
Seismology (PHIVOLCS) reported that there has been a large
increase in volcanic earthquakes at Kanlaon volcano,
Philippines. Between 23rd August and 1st September there were
257 earthquakes measured. This seismic activity is higher than
the background levels, which usually varies from 0 to 4 events
in 24 hour period. Two earthquakes were felt by residents
surrounding the volcano. At 1726 hrs on August 23rd, one
earthquake was felt at Intensity II in Barangay Ara-al, La
Carlota City. A second earthquake at 2227 hrs on August 30th,
was felt at Intensity III in La Castellana and Intensity IV in
La Carlotta City and Bago City. Epicentres of the earthquakes
clustered at the northwest slope of the volcano. These
earthquakes may indicate movements of an active local fault
which may be caused by magma movement beneath the volcano.
Surface observations did not indicate significant change in the
steam emission from the crater. Since Kanlaon Volcano has a
history of sudden steam-driven explosions without precursors,
the public is reminded to avoid entering the 4 km Permanent
Danger Zone. The status of Kanlaon Volcano is maintained at
Alert Level 0. Kanlaon volcano (also spelled Canlaon), the most
active of the central Philippines, forms the highest point on
the island of Negros. The massive 2435-m-high andesitic
stratovolcano is dotted with fissure-controlled pyroclastic
cones and craters, many of which are filled by lakes. The
largest debris avalanche known in the Philippines traveled 33 km
to the SW from Kanlaon. The summit of Kanlaon contains a
2-km-wide, elongated northern caldera with a crater lake and a
smaller, but higher, historically active vent, Lugud crater, to
the south. Historical eruptions from Kanlaon, recorded since
1866, have typically consisted of phreatic explosions of
small-to-moderate size that produce minor ashfalls near the
volcano.
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Mayon volcano - Philippines
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INDONESIA
Volcanoes activity VSI - CVGDM reports : Recent events in 2009 -
2010
Mount Semeru ( Java) - As of the 5th of March 2010 the
CVGHM reported that activity has increased at Semeru volcano in
Indonesia. Harmonic tremor recorded at the volcano over the past
few months November 2009 - 98, December 2009 - 148, January 2010
- 313, February 2010 - 298. In February 2010 ash emissions
occurred on 41 occasions and reached a maximum height 200 m
above the crater. On 28th February, lava avalanched 750 m from
Jonggring Seloko crater. Between April 2009 and 1st March 2010
the activity at Semeru volcano changed to predominately ash
emissions. Since the 25th of February, lava avalanches have
resumed at the volcano. People are advised to stay more than 4
km from the volcano on the SE side, and not approach the summit
from other sides. Semeru, the highest volcano on Java, and one
of its most active, lies at the southern end of a volcanic
massif extending north to the Tengger caldera. The volcano,
rises abruptly to 3676 m above coastal plains to the south.
Gunung Semeru was constructed south of the overlapping Ajek-ajek
and Jambangan calderas. A line of lake-filled maars was
constructed along a N-S trend cutting through the summit, and
cinder cones and lava domes occupy the eastern and NE flanks.
Summit topography is complicated by the shifting of craters from
NW to SE. Frequent 19th and 20th century eruptions were
dominated by small-to-moderate explosions from the summit
crater, with occasional lava flows and larger explosive
eruptions accompanied by pyroclastic flows that have reached the
lower flanks of the volcano. Semeru has been in almost
continuous eruption since 1967
Mount Kaba (Sumatra) - As the 20th of October 2009,
CVGHM reported that seismic activity from Kaba increased in
August and remained elevated in September and October. Inflation
was also detected. When weather permitted, diffuse white plumes
were seen rising 25-50 m above the crater rim and drifting E.
Based on the deformation and increased seismicity, CVGHN raised
the Alert Level to 2 (on a scale of 1-4).
Kaba, a twin volcano with Mount Hitam, has an elongated summit
crater complex dominated by three large historically active
craters trending ENE from the summit to the upper NE flank. The
SW-most crater of 1952-m-high Gunung Kaba, Kawah Lama, is the
largest. Most historical eruptions have affected only the summit
region of the volcano. They mostly originated from the central
summit craters, although the upper-NE flank crater Kawah
Vogelsang also produced explosions during the 19th and 20th
centuries.
Dieng volcanic zone (Java) - As of the 27th of
September 2009, VSI reported that a phreatic explosion occured
on the 27th of September at about 8PM (local time) probably from
South part of the Silaki vent. Mud ejecta have spread 140 m
around the vent. The noise of the explosion was heard to 2 km
away. Previously, as of the 16th of January 2009, the
Volcanological Society of Indonesia (VSI) reported that a
phreatic activity occured on 15th of February at about 6pm
(local time) at the Sibenteng crater. Two explosions opened a
new crater (50 m diameter) and ejected mud and water at about 50
m distance. The alert level was raised at 2. The Dieng plateau
in the highlands of central Java is renowned both for the
variety of its volcanic scenery and as a sacred area housing
Java's oldest Hindu temples, dating back to the 9th century AD.
The Dieng volcanic complex consists of two or more
stratovolcanoes and more than 20 small craters and cones of
Pleistocene-to-Holocene age over a 6 x 14 km area. Prahu
stratovolcano was truncated by a large Pleistocene caldera,
which was subsequently filled by a series of dissected to
youthful cones, lava domes, and craters, many containing lakes.
Lava flows cover much of the plateau, but have not occurred in
historical time, when activity has been restricted to minor
phreatic eruptions. Toxic volcanic gas emission has caused
fatalities and is a hazard at several craters. The abundant
thermal features that dot the plateau and high heat flow make
Dieng a major geothermal prospect. (GVN)
Batur
volcano (Bali) - As of the 12th of November, the
Volcanological Society of Indonesia (VSI) has reported that
hiking trail has been closed at Batur volcano in Bali, Indonesia
due to fears of an eruption. Since the 1st of November 2009
there have been 53 deep and 83 shallow volcanic earthquakes.
Evacuation will be necessary if the alert level is raised to the
next higher level. Currently residents are allowed to continue
activities around the volcano, but should stay away from the
summit area. Batur volcano is a popular tourist location on
Bali, and offers spectacular views of one of the world's most
impressive calderas. The last eruption of Batur volcano was in
2000 when ash emissions reach a height of 300 m above the
summit. The Batur volcano is located at the centre of two
concentric calderas NW of Agung volcano. The outer 10 x 13.5 km
wide caldera was formed during eruption of the Bali (or Ubud)
Ignimbrite about 29,300 years ago and now contains a caldera
lake on its SE side, opposite the satellitic cone of 2152-m-high
Gunung Abang, the topographic high of the Batur complex. The
inner 6.4 x 9.4 km wide caldera was formed about 20,150 years
ago during eruption of the Gunungkawi Ignimbrite. The SE wall of
the inner caldera lies beneath Lake Batur; Batur cone has been
constructed within the inner caldera to a height above the outer
caldera rim. The 1717-m-high Batur stratovolcano has produced
vents over much of the inner caldera, but a NE-SW fissure system
has localized the Batur I, II, and III craters along the summit
ridge. Historical eruptions have been characterised by
mild-to-moderate explosive activity sometimes accompanied by
lava emission. Basaltic lava flows from both summit and flank
vents have reached the caldera floor and the shores of Lake
Batur in historical time. The colour code at Batur is currently
at YELLOW .
G.
Rinjani ( Lombok) - As of the 4th of May, newspaper reported
that on Tuesday eruption followed four smaller eruptions on past
Friday. The nearest village is several miles (kilometers) away
from the 7,795-foot (2,376-meter) Mount Barujari and is not
threatened. The volcano is continuing to erupt, as it has been
doing pretty much continuously since the current phase of
activity began on 2 May. The eruption is located at Barujari
cone Based on analysis of satellite imagery, the Darwin VAAC
reported that during 21 June ash plumes from Rinjani rose to an
altitude of 3 km (10,000 ft) a.s.l. and drifted 55 km N. As of
the 18th of June 2009, the Volcanological Society of Indonesia
(VSI) has reported that base on analysis of satellite imagery,
the Darwin VAAC reported that during the 11th-12th and the 16th
June ash plumes from Rinjani rose to an altitude of 4 km (13,000
ft) a.s.l. and drifted 15-55 km W and WSW. As of the 5th of may,
CVGHM reported that the activity at Rinjani volcano on Lombok
Island was continuing. The eruptive activity eruptions had not
caused important impacts but a small crater began to form in the
eastern part of the mountainous area at Mount Baru Jari.
However, according to scientists, the peak of the activity was
on Saturday with four tremors and the eruption of ash. A team
from the Volcanology and Geological Hazard Mitigation agency is
at Rinjani to monitor the activity, and the national park around
the volcano remains closed to visitors.CVGHM reported than
during 29 April-2 May seismicity from Rinjani increased and
tremor was detected. On 2 May, an eruption produced dense brown
"smoke" that rose 1 km from Barujari cone and was accompanied by
a booming noise. On 4 May, an eruption of ash produced a white
to brown plume that rose 500-700 m above the cone and drifted N.
Fog often prevented observations. The Alert Level was raised to
2 (on a scale of 1-4). Previously, a CVGHM preliminary
information reported that Mt Rinjani , which has gone to yellow
alert following ‘two small explosions on Saturday 2nd of May
2009 during the afternoon. The area of the national park
surrounding the volcano has been immediatly closed to tourists
as a safety measure. Rinjani volcano on the island of Lombok
rises to 3726 m, second in height among Indonesian volcanoes
only to Sumatra's Kerinci volcano. Rinjani has a steep-sided
conical profile when viewed from the east, but the west side of
the compound volcano is truncated by the 6 x 8.5 km, oval-shaped
Segara Anak caldera. The western half of the caldera contains a
230-m-deep lake whose crescentic form results from growth of the
post-caldera cone Barujari at the east end of the caldera.
Historical eruptions at Rinjani dating back to 1847 have been
restricted to Barujari cone and consist of moderate explosive
activity and occasional lava flows that have entered Segara Anak
lak
G.
Merapi (Java) -Based on a pilot observation, the Darwin VAAC
reported that an ash plume from Merapi rose to an altitude of
11.6 km (38,000 ft) a.s.l. on 19 May 2008. Ash was not
identified on satellite imagery.
Previous significative activity : As of the 24th of May 2007,
the Global Volcanism Network (GVN) reported that Merapi volcano
in Indonesia erupted on 23th of May at 0924 local time. Hot
clouds and glowing lava moved 1km down the Gendol river.
Residents in Muntilan reported ashfall over surrounding areas.
As of the 22nd of March 2007, the Global Volcanism Network (GVN)
reported that based on pilot reports, the Darwin VAAC reported
that an eruption plume from Merapi reached an altitude of 6.1 km
(20,000 ft) a.s.l. and drifted NE on 19 March. As of the 10th of
August 2006, the VGHM reported that based on pilot reports, the
Darwin VAAC reported that eruption plumes from Merapi on 2 and 3
August reached altitudes of ~6.1 km (~20,000 ft) a.s.l. and
drifted W. According to CVGHM, during 2-4 August rockfalls
traveled 1 km SE toward the Gendol river and gas plumes reached
a maximum of 400 m above the summit (10,900 ft a.s.l.). On 3
August, the Alert Level was lowered to 2 (on a scale of 1-4). As
of the 27th of July 2006, the VGHM reported that during 19-25
July, gas plumes at Merapi reached maximum heights of 400 m
above the summit (11,000 ft a.s.l.). Lava flows were observed
daily, advancing at a maximum distance of 1.5 km SE toward the
Gendol River. Pyroclastic flows were not observed during the
reporting period. The Alert Level remained at 3 (on a scale of
1-4). On 17 July, CVGHM reported that the Alert Level was
lowered one level to 3 (on a scale of 1-4) in all remaining
areas previously at Alert Level 4 (S slopes). Pyroclastic flows
were not observed during the reporting period. As of the 6th of
July, the VGHM reported that pyroclastic flows and rockfalls at
Merapi decreased in frequency and intensity during 28 June-4
July. Pyroclastic flows were observed during 28-30 June and
reached a maximum distance of 3 km SE along the Gendol River.
Gas plumes were observed during 28 June-1 July and reached a
maximum height of 1 km above the summit (12,800 ft a.s.l.) on 28
June. As of the 29th of June, the VGHM reported that during
21-25 June, seismic signals at Merapi indicated almost daily
occurrence of rockfalls and pyroclastic flows. Due to inclement
weather, pyroclastic flows were only observed on 24 June and
reached a maximum distance of 4 km SE along the Gendol River and
2.5 km SW along the Krasak River. Gas plumes were observed
during 22-25 June and reached a maximum height of 1.5 km above
the summit (14,600 ft a.s.l.) on 24 June. As of the 23rd of
June, the VGHM reported that eruptions continue at Merapi
Volcano in Indonesia. Yesterday there were 15 pyroclastic flows
and 256 lava avalanches. The volcano remains at maximum level 4
alert. On 21 June, visual observation toward the summit was
obscured during the day. Events of pyroclastic flow and lava
avalanches only could be marked from their noise and glare, but
the direction and distance could not be determined. Within this
day seismograph recorded 65 events of multiphase, 256 events of
avalanches earthquakes, 15 events of pyroclastic flow, and 4
events of tectonic earthquakes. On 22 June, the weather was
clear in the morning. Visual observation from Babadan
observatory noted a white-thick solfatara gas emitted moderately
about 700 m from the summit. Seismic record marked 8 events of
multiphase earthquakes, 84 events of avalanches earthquakes, 5
events of pyroclastic flow, and 3 events of tectonic
earthquakes. The events of pyroclastic flow tend to decrease,
while lava avalanches is still fluctuated. Surficial magmatic
activity around the summit is still potential to generate
pyroclastic flow. Areas along 300 m from the side of
K.Krasak/Bebeng, K.Bedog, K.Boyong and K.Gendol, and within
radius of 8 km from the summit is forbidden for any activities.
Update 16th of June 2006 - The VGHM reported that two emergency
workers have been trapped in an underground bunker after an
eruption from Merapi volcano on Wednesday 14th of June and
unfortunatly have been killed. There are the two first victims
since the beginning of the eruptive activity. Gas plumes were
observed almost daily during 7-13 June and reached a maximum
height of 1.2 km above the summit (13,600 ft a.s.l.) on 10 June.
On 8 June a pyroclastic flow, lasting 12 minutes, reached a
maximum distance of 5 km SE toward the Gendol River, the
predominate travel direction since the 27 May earthquake (M
6.2). On 8 June, according to a CVGHM report, the lava-dome
growth rate at Merapi was an estimated 100 thousand cubic meters
per day and the estimated volume was approximately 4 million
cubic meters. An estimated volume loss of 400 thousand cubic
meters on 4 June was due to a partial dome collapse of the S
part of the Geger Buaya crater wall (constructed from 1910 lava
flows). As of the 2nd of June, the VGHM at the Kaliurang
observatory reported lava avalanches events : 122 times toward
K.Krasak and part of K.Boyong with maximum distance of 2.5 km,
100 times toward K.Gendol with maximum distance of 1.5 km.
Pyroclastic flow events also reported from the same site : 15
times toward K.Krasak and K.Boyong with maximum distance of 3.5
km, 5 times toward K.Gendol with maximum distance of 2 km. At
0310 WIB there was lava avalanches toward southwest-west sector
along the upperstreams of K.Boyong, K.Krasak, K.Lamat, K.Sat and
K. Senowo. It has 2.5 km of maximum sliding distance. This is
the first lava avalanches that affected west area during recent
eruption. Seismic record noted : 276 events of avalanches, 127
events of pyroclastic, 36 events of multiphase earthquakes, and
24 events of tectonic earthquakes.Previous update of 26th of May
2006 - according the latest information from VSI, the eruptive
activity declined since the two past days and most of people
come back home in the Umbul Horjo village. However, the
scientists of VSI continues to monitor 24/24 the volcano,
because a new increasing activity could be occurs in the next
days or weeks. On Saturday morning (20th of May), mount Merapi
continues to spew lava from the lava dome. This lava dome on the
top was still growing at a slower rate. Merapi sent 70 flows of
lava and nine outbursts of heatclouds in the first six hours of
Saturday. Some of them reached as far as 3.5 km down the slopes.
Aster Satellite Images of the
Merapi
volcano from Nasa.
Dukono
(Halmahera) - As of the 16th of October 2008, the Volcano
Society of Indonesia (VSI) has reported that based on analysis
of satellite imagery, the Darwin VAAC reported that on 11
October an ash plume from Dukono rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted about 110 km WNW. . On 26 August,
ash plumes rose to an altitude of 1.5 km (5,000 ft) a.s.l. and
drifted W and WNW. As of the 5th of June, VS) has reported that
incandescence at Dukono's summit during 31 March-24 April. On 25
April, incandescent material was ejected 25 m above the summit.
During 30 April-2 May seismicty increased. On 25 May, an ash
plume rose to an altitude of 1.4-2.1 km (4,600-6,900 ft) a.s.l.
and was accompanied by thunderous and booming sounds. On 29 May,
an ash plume rose to an altitude of 2.3 km (7,500 ft) a.s.l. and
again was accompanied by thunderous and booming sounds. The
Alert Level was raised to 3 (on a scale of 1-4). Residents and
visitors were not permitted within 3 km of the summit CVGHM
reported incandescence at Dukono's summit during 31 March-24
April. Geologic Summary. Reports from this remote volcano in
northernmost Halmahera are rare, but Dukono has been one of
Indonesia's most active volcanoes. More-or-less continuous
explosive eruptions, sometimes accompanied by lava flows,
occurred from 1933 until at least the mid-1990s, when routine
observations were curtailed .
G.
Karangetang (Siau Island)- As of the 12th of November 2009,
the CVGHM reported that according to news articles, a
pyroclastic flow and a lahar descended the flanks of Karangetang
on the 4th of November. Residents saw active lava flows the next
day. On the 11th of November, incandescent material was ejected
5 m into the air. Based on a pilot observation and analyses of
satellite imagery, Darwin VAAC reported an ash plume to 3 km
a.s.l. and drifted 90-185 km W on 3 November 2009. Previous news
:CVGHM reported that during 1-6 June 2009 lava flows from
Karangetang traveled 50 m E and 600 m SE. Incandescent rocks,
from the main craters and ends of the lava flows, traveled as
far as 2 km towards multiple river valleys, including the Keting
River to the S. On 1 June, white-to-gray-to-brownish plumes rose
700 m above the main crater. Incandescent lava was ejected
500-700 m. On 4 June, tremor amplitude and the number of
earthquakes decreased. During 4-6 June, white plumes rose 50-300
m from the main crater. On 7 and 8 June, fog often prevented
observations and incandescent rocks were rarely seen. The Alert
Level was lowered to 3 (on a scale of 1-4) on 9 June. As of the
2nd of June 2009, CVGHM reported that CVGHM reported that
seismicity from Karangetang increased during 30-31 May and
tremor was detected. On 30 May, diffuse white plumes rose 10-50
m high and incandescence was seen at the crater. On 31 May,
white emissions from Utama Crater in the N part of the summit
region rose 100 m. Incandescent material traveled as far as 2.3
km, mostly down the S flank. Ash plumes that rose 25-700 m were
accompanied by thunderous sounds. The Alert Level was raised to
4, the highest level on a scale of 1-4. CVGHM reported that on
28th of May2009, based on a pilot observation, the Darwin VAAC
reported that on the 24th of May an ash plume from Karangetang
rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 75
km S. Karangetang (Api Siau) volcano lies at the northern end of
the island of Siau, north of Sulawesi. The 1784-m-high
stratovolcano contains five summit craters along a N-S line.
Karangetang is one of Indonesia's most active volcanoes, with
more than 50 eruptions recorded since 1675 and many additional
small eruptions that were not documented in the historical
record (Catalog of Active Volcanoes of the World: Neumann van
Padang, 1951). Twentieth-century eruptions have included
frequent explosive activity sometimes accompanied by pyroclastic
flows and lahars. Lava dome growth has occurred in the summit
craters; collapse of lava flow fronts has also produced
pyroclastic flows.
Anak
Krakatau ( Sunda Strait) - As of the 4th of November 2009,
The Volcanological Society of Indonesia (VSI) has reported that
the Alert level at Anak Krakatau volcano in Indonesia has been
lowered from Alert Level III to Alert Level II. Explosion
earthquakes measured over the past few months were August 4311,
September 541, and October 34. There has been a significant
decline in eruptive activity at the volcano since August 2009.
As of the 22nd of August 2009, a Volcano Discovery Team has
reported that the explosive activity at Krakatau has resumed
over the past weeks. Strong vulcanian-type eruptions from the
growing lava dome in the new crater occur at intervals of 90-360
minutes as one of the Volcano Discovery Team correspondants
reported from a recent visit. Blocks are being thrown over the
whole of the southern part of the island, including the forest
and often reach the water as well. Small pyroclastic flows
sometimes develop on the slope of the summit cone.A news report
on 18 June 2009noted that activity at Krakatau had increased
significantly. According to the head of the volcano monitoring
post in Pasauran village there were 828 small eruptions in the
previous six days, reaching the rate of a new explosion every
three minutes. Observers on beaches in Java could clearly see
rising white gas-and-steam plumes along with incandescent ejecta
at night. Residents also reported loud explosion noises. The
level of activity decreased again on 19 June, and the Alert
Level remained at 3 (on a scale of 1-4).As of the 13th of June
2009, Tom Pfeiffer reported that during its recent expedition
(from 3-8 June 09), Anak Krakatau continued to display strong
strombolian activity, often accompanied by loud blasts, from a
new vent located between the old summit crater and the 2007
crater. This activity has essentially filled the 2007 crater
with a new cinder cone and 'healed' the 2007 scar. At the time
of leaving the island, activity was still going strong. As of
the 6th of May 2009, the Volcanological Society of Indonesia
(VSI) has reported that the number of eruptions from Anak
Krakatau increased significantly at the end of March and
continued through 5 May. Direct observations of the crater on
24, 25, and 29 April revealed that the eruption originated from
a crater on the W slope of Anak Krakatau. Ash plumes generally
drifted E and caused ashfall within a 5 km radius of the crater.
Clear weather on 5 May allowed for visual observations; "smoke"
rose 500 m above the crater. Anak Krakatau until crossing the
Kulon Tip territory, in the Banten Province and spread in the
distance more than 60 Km The renowned Krakatau volcano lies in
the Sunda Strait between Java and Sumatra. Collapse of the
ancestral Krakatau edifice, perhaps in 416 AD, resulted in a
7-km-wide caldera. Remnants of this volcano formed Verlaten and
Lang Islands; subsequently Rakata, Danan, and Perbuwatan
volcanoes were formed, coalescing to create the pre-1883
Krakatau Island. Caldera collapse during the catastrophic 1883
eruption destroyed Danan and Perbuwatan volcanoes, and left only
a remnant of Rakata volcano. The post-collapse cone of Anak
Krakatau (Child of Krakatau), constructed within the 1883
caldera at a point between the former cones of Danan and
Perbuwatan, has been the site of frequent eruptions since 1927.
Live Webcam
Ibu
volcano (Halmahera)) - As of the 6th of August 2009, the
CVGHM reported that results of the monitoring visually that was
carried out from the Observation Post in Gamsungi, the eruption
smoke that was observed on July 15th to August 4th being white
grey with the height 300 through to 400 m. on the peak. On
August 2, at 0455 hrs WIT a lava flow happened. At 1800-2200 hrs
WIT heard was the thunderous sound totalling 5 times followed
with the firelight emergence in the peak of Ibu. On August 3, at
1830 to 2230 hrs WIT observed was the existence of firelight in
the peak of Ibu. High firelight that was observed from the Duono
Village, Going and Sanghaji be as high (20 m) as well and was
accompanied by the quite hard thunderous sound. Lava of Ibu
continued to grow and to be able to have been seen from the
Duono Village. The conclusion is that the data showed the
existence of the rise in the number of eruption earthquakes and
bellows that was accompanied by the eruption and the material
throw glowing that could be observed visually clearly. The
truncated summit of Ibu stratovolcano along the NW coast of
Halmahera Island has large nested summit craters. The inner
crater, 1 km wide and 400 m deep, contained several small crater
lakes through much of historical time. The outer crater, 1.2 km
wide, is breached on the north side, creating a steep-walled
valley. A large parasitic cone is located ENE of the summit. A
smaller one to the WSW has fed a lava flow down the western
flank. A group of maars is located below the northern and
western flanks of the volcano. Only a few eruptions have been
recorded from Ibu in historical time, the first a small
explosive eruption from the summit crater in 1911. An eruption
producing a lava dome that eventually covered much of the floor
of the inner summit crater began in December 1998.
VSI
website
Batu Tara volcano (Flores) - As of the 2nd of July
2009, that based on analysis of satellite imagery, the Darwin
VAAC reported that during 25-30 June ash plumes from Batu Tara
rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted
35-130 km SW, W, and NW. The small isolated island of Batu Tara
in the Flores Sea about 50 km north of Lembata (formerly
Lomblen) Island contains a scarp on the eastern side similar to
the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation
covers the flanks of Batu Tara to within 50 m of the 748-m-high
summit. Batu Tara lies north of the main volcanic arc and is
noted for its potassic leucite-bearing basanitic and tephritic
rocks. The first historical eruption from Batu Tara, during
1847-52, produced explosions and a lava flow. The Current Colour
Code for Batu Tara is ORANGE
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RUSSIA -
Bezymianny volcano (Kamtchatka)
May 8th, 2010
As of the
7th of May, the Kamchatkan Volcanic Eruption Response Team
(KVERT) has reported that activity of the volcano continues and
its aerosolic plumes could affect low-flying aircraft. Strong
volcanic activity of Klyuchevskoi volcano obscured seismic data
of Bezymianny last week. Clouds obscured the volcano all week.
According to satellite data, a weak thermal anomaly over the
lava dome was registering on April 28th-30th and May 1st-2nd.
As of the
30th of April, KVERT reported that activity of the volcano
continues. Strong volcanic activity of Klyuchevskoi volcano
obscured seismic data of Bezymianny last week. Moderate
fumarolic activity of the volcano was observed on April
27th-28th, clouds obscured the volcano in the other days of
week. According to satellite data, a weak thermal anomaly over
the lava dome was registering all week. As of the 16th of April,
the Kamchatkan Volcanic Eruption Response Team (KVERT) has
reported that strong volcanic activity of Klyuchevskoi volcano
obscured seismic data of Bezymianny last week. Moderate
fumarolic activity of the volcano was observed on April
8th-13th, clouds obscured the volcano in the other days of week.
According to satellite data, a weak thermal anomaly over the
lava dome was registering on April 8th-13th.Prior to its 1955-56
eruption, Bezymianny volcano had been considered extinct. Three
periods of intensified activity have occurred during the past
3,000 years. The latest period, which was preceded by a
1,000-year quiescence, began with the dramatic 1955-56 eruption.
That eruption, similar to the 1980 event at Mount St. Helens,
produced a large horseshoe-shaped crater that was formed by
collapse of the summit and an associated lateral blast.
Subsequent episodic but ongoing lava-dome growth, accompanied by
intermittent explosive activity and pyroclastic flows, has
largely filled the 1956 crater.
KVERT
RUSSIA
- Sheveluch volcano ( Kamchatka)
May
8th, 2010
As of the
7th of May, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that explosive-extrusive eruption of the
volcano continues. Seismicity was above background levels all
week. According to seismic data, possibly ash plumes rose up to
4.5 km (14,800 ft) ASL all week. According to visual data,
clouds obscured the volcano all week. According to satellite
data, a big thermal anomaly was registering over the lava dome
all week. Ash plumes extending about 18 km (11 mi) to the west
from the dome was noted on May 3rd. As of the 30th of April, the
Kamchatkan Volcanic Eruption Response Team (KVERT) reported that
explosive-extrusive eruption of the volcano continues.
Seismicity was above background levels all week. According to
seismic data, possibly ash plumes rose up to 5.7 km (18,700 ft)
ASL all week. According to visual data, ash plumes from hot
avalanches rose up to 3.0 km (9,800 ft) ASL on April 22nd-25th.
Strong and moderate fumarolic activity of the dome was noting on
April 22nd-25th. Clouds obscured the volcano in the other days
of week. According to satellite data, a big thermal anomaly was
registering over the lava dome all week. An ash plumes extending
about 60 km (37 mi) to the south-east from the dome was noted on
April 28th.
The high,
isolated massif of Sheveluch volcano (3283 m) rises above the
lowlands NNE of the Kliuchevskoi volcano group. Sheveluch is one
of Kamchatka's largest and most active volcanic structures. The
summit of roughly 65,000-year-old Stary Shiveluch is truncated
by a broad 9-km-wide late-Pleistocene caldera breached to the
south. Many lava domes dot its outer flanksStrong culmination
explosive eruption of the lava dome of Sheveluch volcano
occurred in 1993, 2001, 2004 and two in 2005.
Live cam link
RUSSIA
- Karymsky volcano (Kamchatka)
May
8th, 2010
A s of the
7th of May, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that explosive activity of the volcano
continues. Seismic activity of the volcano was above background
levels all week. According to seismic data, possibly weak ash
plumes rose up to 3.0 km (9,800 ft) ASL last week. According to
satellite data, a thermal anomaly was registering over the
volcano on April 28th-30th and May 1st-2nd.
As of the
30th of April, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that explosive activity of the volcano
continues. Seismic activity of the volcano was above background
levels all week. According to seismic data, possibly weak ash
plumes rose up to 3.0 km (9,800 ft) ASL last week. A strong
seismic event near the volcano was registered on April 28th, but
ash plumes were not noted in the area of the volcano on the
satellite images after this event. According to visual data by
volcanologist who work at the area of the volcano, gas-steam
plumes containing ash rose up to 3.0 km (9,800 ft) ASL on April
20th-21st. Strombolian activity of the volcano was observing
sometimes at night time. According to satellite data, a thermal
anomaly was registering over the volcano all week. Karymsky, the
most active volcano of Kamchatka's eastern volcanic zone, is a
symmetrical stratovolcano constructed within a 5-km-wide caldera
that formed during the early Holocene. The caldera cuts the
south side of the Pleistocene Dvor volcano and is located
outside the north margin of the large mid-Pleistocene Polovinka
caldera, which contains the smaller Akademia Nauk and Odnoboky
calderas. The latest eruptive period began about 500 years ago,
following a 2300-year quiescence. Much of the cone is mantled by
lava flows less than 200 years old. Historical eruptions have
been vulcanian or vulcanian-strombolian with moderate explosive
activity and occasional lava flows from the summit crater.
RUSSIA
- Kliuchevskoy volcano (Kamchatka)
May
8th, 2010
As of the
7th of May, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that explosive-effusive eruption of the volcano
continues. Seismicityof the volcano was above background levels
all week. According to visual data, clouds obscured the volcano
all week. According to satellite data, a big thermal anomaly was
registering over the volcano all week. Ash plumes extending
about 125 km (78 mi) to the north and about 70 km (43 mi) to the
west were noted on May 2nd and May 3rd, respectively. A height
of ash plume was 5.5 km (18,049 ft) ASL on May 3rd (according by
satellite data). Gas-steam plumes extended until 55 km (34 mi)
to the west and south-west from the volcano on May 2nd-3rd.
As of the
30th of April, KVERT reported The activity of the volcano could
affect international and low-flying aircraft. Seismicity of the
volcano was above background levels all week. According to
visual data, Strombolian activity of the volcano continues. An
effusion of lava flows on the volcanic flanks continues too.
Strong gas-steam plume containing small amount of ash rose up to
7.3 km (23,900 ft) ASL and extending to the west and south-west
from the volcano on April 25th-27th. Moderate gas-steam with
small amount of ash activity was observing on April 22nd. Clouds
obscured the volcano in the other days of week. According to
satellite data, a big thermal anomaly was registering over the
volcano all week. A weak ash plumes extending about 65 km (40
mi) to the west were noted on April 24th. Gas-steam plumes
extended until 55 km (34 mi) mainly to the west and southwest
from the volcano on April 24th-27th.
Kliuchevskoi
flanks Kamen volcano to the SW and Ushkovsky volcano to the NW.
More than 100 flank eruptions have occurred during the past
roughly 3000 years .
Live cam link
RUSSIA - Koriaksky volcano
November 14th, 2009
As of the
12th of November, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that during 30 October-6 November seismic
activity from Koryaksky did not exceed background levels.
Fumarolic activity was noted on 29 October and during 4-5
November. The Level of Concern Colour Code was lowered to Green.
Fumarolic activity of the volcano continues and such activity is
normal for the volcano. Last time there were ash plumes at the
volcano on August 13th-27th. But strong gas-steam plumes could
affect low-flying aircraft. Seismicity didn't exceeded
background levels all week. Moderate fumarolic activity of the
volcano was observing on October 29th and November 4th-5th.
Clouds obscured the volcano in the other days of week. According
to satellite data, the volcano was quiet last week.
As of the 6th
of November, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that fumarolic activity of the volcano
continues and such activity is normal for the volcano.seismicity
didn't exceeded background levels all week. Moderate fumarolic
activity of the volcano was observing on October 29th and
November 4th-5th. Clouds obscured the volcano in the other days
of week. According to satellite data, the volcano was quiet last
week.
As of the 30th October, KVERT reported that seismicity didn't
exceeded background levels all week, weak volcanic tremor was
registering in the area of the volcano on October 24th-27th.
Moderate fumarolic activity of the volcano was observing on
October 23rd-25th and 28th-29th. Clouds obscured the volcano on
October 26th-27th. According to satellite data, the volcano was
quiet last week.
Moderate
fumarolic activity of the volcano was observed on October 17-22.
According to satellite data, the volcano was quiet last week.
Moderate fumarolic activity of the volcano sometimes with weak
emissions of ash was observed on October 01-03 and 05-07.
According to satellite data, a weak thermal anomaly was
registering over the volcano on October 2nd. According to visual
data, gas-steam plumes rose up to 3.7 km (12,100 ft) ASL on
September 12-17. Aerosolic plumes extended >10 km (6 mi) to the
eastern directions from the volcano. Clouds obscured the volcano
in the other days of week. According to satellite data, the
volcano was quiet. . According to visual data, gas-steam plumes
raising up to 3.4 km (11,100 ft) ASL were observed on September
4th and 6th. Clouds obscured the volcano in the other days of
week. According to satellite data, the volcano was quiet.
Seismicity of the volcano didn't exceeded background levels all
week but a volcanic tremor was registering on August 27th-28th
and September 1st. According to visual data, gas-steam plumes
raising up to 3.7 km (12,100 ft) ASL and extending to the
different directions from the volcano were observed last week.
According to satellite data, the volcano was quiet. According to
visual data, gas-steam plumes containing ash raising up to 3.7
km (12,100 ft) ASL and extending to the different directions
from the volcano were observed on August 26-27. According to
satellite data, ash plumes extending >385 km (>239 mi) mainly to
the eastern directions from the volcano were registered on
August 20-27. As of the 21st of August, (KVERT reported that
activity of the volcano continues. Seismicity was slightly above
background levels last week. According to visual data, gas-steam
plumes containing ash raising up to 3.5-4.2 km (11,500-13,800
ft) ASL and extending to the different directions from the
volcano were observed on August 16th-20th. Before ash plumes the
height of gas-steam plumes was about 3.5-5.0 km (11,500 - 16,400
ft) ASL on August 13th-16th. According to satellite data, ash
plumes extending about 215 km (>133 mi) mainly to the eastern
and western directions from the volcano were registered on
August 16th-20th.
According to
satellite data, an ash plume extending >180 km (>112 mi) to the
ESE from the volcano was registered on August 12th. According to
satellite data, a thermal anomaly was registered on July 20th.
According to
satellite data, gas-steam plumes containing an ash extending for
about 100 km (62 mi) to the NE from the volcano were noted on
April 17-18 and 22nd. There was registered an SO2 signal (OMI
data) for about 15 km (9 mi) from Koryaksky on April 20th. On 11
April, KVERT staff reported ashfall in Petropavlovsk-Kamchatsky
(30 km S). Ash accumulated to 0.1-2.5 cm thickness near the
Institute of Volcanology and Seismology (IVS) FED RAS. The Level
of Concern Colour Code remained Orange. According to satellite
data, aerosolic plumes containing ash extended about 225 km (140
mi) to the south-east from the volcano on March 25-26. Seismic
activity of the volcano was above background levels on March
13th and at background levels during other days of the week.
Aerosolic plumes containing small amount of ash raising up to
4.0 km (13,200 ft) ASL and extending to the eastern directions
from the volcano were observed all week. As of the 6th of March,
KVERT reported that during 3-4 March gas plumes containing a
small amount of ash rose to an altitude of 3.7 km (12,100 ft)
a.s.l. and drifted more than 200 km ENE. Ash deposits were seen
at the summit. Ash deposits 1-2 mm thick accumulated in an area
between Koryaksky and Avachinsky volcanoes. The Level of Concern
Color Code was raised to Orange. A strong fumarolic activity of
the volcano was observed on February 22-26. The volcano was
obscured by clouds during other days. According to satellite
data, an ash plume extending about 50 km (31 mi) and an
aerosolic plume with ash to 200 km (124 mi) to the ENE from the
volcano were observed on February 25th. During 6-7 January
gas-and-steam plumes drifted SW. The Level of Concern Color Code
was lowered to Yellow. As of the 2nd of January, the Kamchatkan
Volcanic Eruption Response Team (KVERT) reported that weak
explosive activity of the volcano continued. According to
scientists, probably activities of the volcano will increase
again. The activity of the volcano is dangerous for low-flying
aircraft. Seismic activity of the volcano was at background
levels: from 1 to 7 volcanic earthquakes were noting each day at
the volcano. Possibly an episode of volcanic tremor were
registered on December 30-31 and January 1st. According to
visual data, gas-steam plumes possibly containing small amount
of ash moves on the surface of north-western slope of the
volcano on December 30-31. Clouds obscured the volcano in the
other days. As of the 28th of December, KVERT informed that
moderate explosive Volcanian type eruption of the volcano
occured. Ash plumes raise about 4.0 km (13.200 ft) ASL and
extended to the north-west from the volcano. No seismic data
about this event by technical reasons. Gas-steam plumes
containing small amount of ash were registering during daylight
hours on the satellite images on December 23-25. Strong
fumarolic activity were noted at the volcano from November,
2008. According to satellite data, on December 24th of December,
at 23:34 UTC (NOAA 17, 4m5)) and 23:42 UTC ( TERRA MODIS, 31m32)
a dense ash plume extended over 60 km (37 mi) and a poor ash
plume extended 140 km (87 mi) to the northeast of the volcano.
According to visual data by observers from Nalychevo valley, a
dark column rose about 200-300 m from the vent of a fumarole on
the northwestern flank of Koryaksky volcano on December 24. The
fumarole is located about 3.0 km ASL. Observers heard a boom
from the volcano at night. According to seismic data (KB GS
RAS), only 2 earthquakes were registered on December 23 on the
depth of 5.0 km under the volcano. KVERT continues to monitor
Koryaksky volcano.
The colour
code at Koryaksky is currently at YELLOW. The large symmetrical
Koryaksky stratovolcano is the most prominent landmark of the
NW-trending Avachinskaya volcano group, which towers above
Kamchatka's largest city, Petropavlovsk. Erosion has produced a
ribbed surface on the eastern flanks of the 3456-m-high volcano;
the youngest lava flows are found on the upper western flank and
below SE-flank cinder cones. No strong explosive eruptions have
been documented during the Holocene. Extensive Holocene lava
fields on the western flank were primarily fed by summit vents;
those on the SW flank originated from flank vents. Lahars
associated with a period of lava effusion from south- and
SW-flank fissure vents about 3900-3500 years ago reached Avacha
Bay. Only a few moderate explosive eruptions have occurred
during historical time. Koryaksky's first historical eruption,
in 1895, also produced a lava flow.
RUSSIA - Kizimen volcano
November 14th, 2009
As of the
13th of November, the Kamchatkan Volcanic Eruption Response Team
(KVERT) reported that fumarolic activity of the volcano
continues and such activity is normal for the volcano. KVERT
continues to watch the Kizimen volcano. Seismicity was slightly
above background levels on November 6th, 8th and 10th, and
didn't exceeded background levels in the other days of week.
According to satellite data, the volcano was quiet or obscured
by clouds last week. As of the 30th of October, the Kamchatkan
Volcanic Eruption Response Team (KVERT) has reported that
activity of the volcano continues. KVERT continues to watch the
Kizimen volcano. Seismic activity of the volcano was slightly
above background levels on October 26th and didn't exceeded
background levels in the others days of week. According to
satellite data, the volcano was quiet or obscured by clouds last
week.
Seismic activity of the volcano was above background levels on
October 15-19 and didn't exceeded background levels in the
others days of week. According to satellite data, a weak thermal
anomaly over the volcano was registered on October 16th.
Many shallow
earthquakes were registered during October 09-11. According to
satellite data, a weak thermal anomaly over the volcano was
registered on October 9th.
As of the
10th of october, KVERT reported that seismic activity of the
volcano increased in the last day. Many shallow earthquakes (one
with magnitude 3.1) were registered during October 09.
Intensification of seismic activity of the volcano is possibly.
Possibly there is a preparation of an explosive eruption of the
volcano. During September, 2009, seismicity of the volcano was
mainly at background levels but since October a number of
shallow volcanic earthquakes near the volcano began to increase.
According to satellite data by KVERT, a weak thermal anomaly
over the volcano was noted on September 17 and 21. As of the
28th of August, the Kamchatkan Volcanic Eruption Response Team
(KVERT) has reported that activity of the volcano continues.
Strong explosive eruption possible in case of further seismicity
increasing. Seismicity was above background levels on August
20-22 and at background levels in the other days of this week.
According to satellite data, volcano was quiet.
As of the
14th of August, the Kamchatkan Volcanic Eruption Response Team
(KVERT) has reported that seismic activity of the volcano
continued to increase since July 11. Strong explosive eruption
possible in case of further seismicity increasing. Seismicity
was above background levels on August 7th and 9th-11th; and at
background levels in the other days of this week. According
satellite data, volcano was obscured by clouds last week, a
thermal anomaly was not registered this week. As of the 31st of
July, the Kamchatkan Volcanic Eruption Response Team (KVERT)
reported that seismic activity of the volcano increased since
July 11th. Shallow earthquakes were registered during three
weeks. Strong explosive eruption possible in case of further
seismicity increasing. Seismicity was above background levels,
several tens of shallow earthquakes per day were registered.
Kizimen is an isolated, conical stratovolcano that is
morphologically similar to Mount St. Helens prior to its 1980
eruption. The summit of Kizimen consists of overlapping lava
domes, and blocky lava flows descend the flanks of the volcano,
which is the westernmost of a volcanic chain north of Kronotsky
volcano. The 2376-m-high Kizimen was formed during four eruptive
cycles beginning about 12,000 years ago and lasting 2000-3500
years. The largest eruptions took place about 10,000 and
8300-8400 years ago, and three periods of long-term lava dome
growth have occurred. The latest eruptive cycle began about 3000
years ago with a large explosion and was followed by lava dome
growth lasting intermittently about 1000 years. An explosive
eruption about 1100 years ago produced a lateral blast and
created a 1.0 x 0.7 km wide crater breached to the NE, inside
which a small lava dome (the fourth at Kizimen) has grown. A
single explosive eruption, during 1927-28, has been recorded in
historical time.
RUSSIA - Sarychev volcano (Kurile islands)
September 24th, 2009
As of the
23rd of September, the Sakhalin Volcanic Eruption Response Team
(SVERT) has reported that again weak volcanic activity
continues. According to satellite data during the week weak
steam-gas emissions and thermal anomalies were observed. Since
June 15th, there have been no additional large ash explosions.
According to satellite images from today, ( MODIS 0120 hrs UTC)
mostly cloudy at volcano. Sarychev Peak volcano is not monitored
with ground-based instrumentation to detect earthquakes. SVERT
uses satellite data to observe the volcano each day, weather
permitting. The next update will be sent tomorrow or earlier if
a significant change is detected.
As of the 7th
of July, the Sakhalin Volcanic Eruption Response Team (SVERT)
has reported that according to satellite images from today,
(MODIS 0257 hrs UTC) steam-gas emission stretches to northeast
20 km. Its height is 2-3 km. An intense thermal anomaly is also
observed. IMGG volcanologists are visiting Matua Island this
week to investigate the eruption. Since June 16th, there have
been no additional large ash explosions. SVERT reported that an
intense thermal anomaly from Sarychev Peak was detected on
satellite imagery during 24-30 June. Gas-and-steam plumes
drifted 9 km NW on 24 June, S on 26 June, 26 km SSE on 28 June,
and 40 km SE at an altitude of 3 km on 29 June. As of the 22nd
of June, according data of MODIS 0906220013 UTC, a high
steam-gas emission stretched north to 29 km at a height up to
1.5 km. An intense thermal anomaly was visible on 24 June. As of
the 19th of June, according to data of MODIS 0906190120 UTC and
MTSAT the intensity of activity has declined. Cloudy conditions
obscure observations. Possible small volcanic emissions my be
occurring. According to NOAA AVHRR data at 09170.0214, a strong
thermal anomaly was detected but no ash signal was detected.As
of the 18th of June, according to data of MODIS 0906180037 UTC
the eruption of the volcano continued. The emission of the
mainly steam-gas stretches to south-west direction. weak ash
falls were observed in Yuzhno-Sakhalinsk. According to data of
MTSAT great volcanic explosions occurred at 14 June at 1930 UTC
and 15 June at 0130 UTC. The suggested height of ash plume is
greater than 26,000 feet (8 km). The Tokyo VAAC has estimated
the cloud height up to 54000 feet above sea level. According to
MODIS 0906150007 UTC all ash cloud are seen on the south-east
and north-west. Whole length is more than 600 km. As of the 12th
of June, SVERT detected a strong eruption from Sarychev Peak
(Matua island, Central Kuril Islands). Ash emission seen in
MODIS image from 0019UTC shows was attached to the volcano and
extended 200 km to the south-west and 105 km to the south-east.
The Tokyo VAAC reported the height of the ash cloud at 34000
feet above sea level. It appears the eruption began around
0200UTC on 12 June. Based on past eruptions at Sarychev,
explosive activity could continue for days to weeks. A cyclone
in the Kuril Islands makes observation of this eruption
difficult. Sarychev is not monitored with ground-based
instruments. SVERT will continue to monitor the eruption with
MODIS and NOAA satellite imagery as weather allows and issue
further reports as additional information becomes available. The
regularly-active cone of Sarychev Peak (1446 M) is 6 km in
diameter and forms the north-western part of Matua Island. On
the south-west, the cone adjoins to the remains of a caldera
forming the south-east half of the island. The summit crater has
a diameter of about 250 m and a depth of 250m. The inner walls
are precipitous and in some places even overhanging. The bottom
of the crater is filled with solidified lava in the form of
slightly convex shield. The ancient lava flows of the central
cone descend on the south-eastern slope of somma. The modern
flows of the central cone form small tongues near the crater.
Lava flows consist of two-pyroxene basalts and andesite-basalts.
Sarychev Peak is one of the most active Kuril volcanoes. Prior
eruptions at Sarychev Peak are as follows: 1760–a very great
explosive eruption; winter 1878-1879 – a quiet lava outflow,
1928–explosive eruption, 1930 – great explosive eruption lasting
13 hours; 1946 – a very great eruption, explosions with large
bombs landing as far as 7 km from the crater and the height of
ash emissions reaching more than 6 km; 1954 – small ash
emissions; in 1960 - a brief explosive eruption. The most recent
eruption began on September 23, 1976 when a series of explosions
destroyed the old lava plug. The ash plume extended 300 km to
the north-north-east and reached the height of 2.5 km. The
eruption terminated with lava outflows. In the August 2008 the
personnel of SVERT group conducted observations of the volcano
Sarychev Peak, noting large constant fumarolic activity.
Precursory signs of volcanic activity were not observed.
(information from SVERT)
RUSSIA - Kolokol group (Kurile Islands)
September 3rd, 2009
Based on
analyses of satellite imagery, SVERT reported that on 26 August
a gas-and-steam plume possibly containing ash rose from Berg
(part of the Kolokol Group of volcanoes) to an altitude greater
than 6 km (19,700 ft) a.s.l. and drifted NE. This group of
Holocene volcanoes in central Urup Island is named after its
most prominent volcano, Kolokol. Berg and Trezubetz volcanoes,
flanking Kolokol on the NW, have breached summit calderas
partially filled by lava domes. Trezubetz, whose name means
"trident," has
an eroded crater rim with three large peaks when seen at sea
from the north. Kolokol volcano rises to 1328 m and is sometimes
known as Urup-Fuji because of its symmetrical profile. The
crater of Kolokol is not well preserved, but the volcano
displays no evidence of glacial erosion. Several lava flows
originate from Kolokol; one of these extends almost to the Sea
of Okhotsk coast. A viscous lava flow armoring the SE flank is
probably the most recent from Kolokol. Borzov volcano, the
oldest of the group, lies to the SW of
Kolokol. Eruptions of the Kolokol volcano group have been
observed in historical time since the late-18th century. Berg
volcano has been most active, but Trezubetz erupted in 1924.
(GVN/GVP)
RUSSIA -
Ebeko volcano (Kurile Islands)
October
30th, 2009
As of the
29th of October, the Kamchatkan Volcanic Eruption Response Team
(KVERT) has reported that based on analyses of satellite
imagery, the Tokyo VAAC reported that on 26 October a possible
eruption plume from Ebeko rose to an altitude of 8.8 km (29,000
ft) a.s.l. and drifted E. Emissions continued the next day. As
of the 24th of July, the Kamchatkan Volcanic Eruption Response
Team (KVERT) has reported that activity of the volcano
continues. Moderate gas-steam emission sometimes with small
amount of ash occurred at Ebeko. The danger of sudden ash
explosions up to 3.5 km (11,500 ft) ASL exists. Activity of the
volcano could affect low-flying aircraft. According to satellite
monitoring, a thermal anomaly and ash plumes were not
registered. Ebeko volcano is not monitored with seismic
instruments. KVERT uses satellite monitoring and receives
occasional visual observations from Paramushir Island. As of the
24th of April, the Kamchatkan Volcanic Eruption Response Team
(KVERT) has reported that during 24 April-1 May 2009 observers
from Severo-Kurilsk, about 7 km E of Ebeko, observed continued
activity. Gas-and-steam plumes with some ash content rose to an
altitude of 3.5 km (11,500 ft) a.s.l. and drifted 6 km in
multiple directions. On 23 April, a small amount of ash fell in
Severo-Kurilsk. Satellite imagery revealed strips of ash
deposits radiating from the crater in different directions on 29
and 30 April. The Level of Concern Color Code remained at
Yellow. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies
the northern end of Paramushir Island. Three summit craters
located along a SSW-NNE line form Ebeko volcano proper, at the
northern end of a complex of five volcanic cones. The eastern
part of the southern crater of Ebeko contains strong solfataras
and a large boiling spring. The central crater of Ebeko is
filled by a lake about 20 m deep whose shores are lined with
steaming solfataras; the northern crater lies across a narrow,
low barrier from the central crater and contains a small, cold
crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate
explosive eruptions from the summit craters. Intense fumarolic
activity occurs in the summit craters of Ebeko, on the outer
flanks of the cone, and in lateral explosion craters.(From
KVERT).
To view current activity of Ebeko - More about
Kurile Islands
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NEW
ZEALAND - White island volcano
October
24th, 2008
A White
Island's Crater Lake has continued to rise since December 2007,
after being almost completely evaporated in late October 2007.
By 23 October the lake was reported to have risen 15 m and was
beginning to affect the geothermal features on the Main Crater
floor. New springs formed on the floor and old springs flowed
again. The lake temperature remained hot at 57 degrees Celsius
and the color had changed to light green, reflecting a decrease
in suspended sediment. High-temperature fumaroles (101-103
degrees Celsius) were located on the S side of the Main Crater
floor. Steam, gas, and mud emissions had increased from the
largest vent during the previous few weeks. The Alert Level
remained at Level 1 (on a scale of 0-5), indicating signs of
volcano unrest.Live
cam link -
other webcam
NEW
ZEALAND - Ruapehu volcano
September 18th, 2008
As of the
18 th of September, Geonet bulletin (INGS) reported this day
that Ruapehu appears to be entering a new heating cycle. The
Crater Lake temperature has risen to 22°C this month, from 16°C
in August, a change accompanied by some volcanic tremor. Between
October 2007 and June 2008 the temperature varied between 34°C
and 37°C. Sulphur dioxide and carbon dioxide levels in the
volcano's plume are also showing an upwards trend, consistent
with the rising temperature within the Crater Lake. There is
nothing unusual about any of this, because cyclic activity in
the Crater Lake is very common at Ruapehu. The volcano in
central North Island, last erupted on Sept. 25 2007, spitting 2
metre (6 feet) boulders distances of up to 2 kms (1.5 miles).
Ruapehu's elevated alert level has not been changed, but IGNS
reported on Tuesday that activity within the mountain was
greater, with high levels of gas spewing out, a warmer than
average crater lake and ongoing volcanic tremors. The volcano
remains in a status of unrest and the possibility of further
activity remains. If further eruptions occur, they may occur
without warning. As of the 3rd of May, the Institute of
Geological & Nuclear Sciences (IGNS) has reported that Ruapehu
volcano in New Zealand is showing signs of increasing activity.
The Department of Conservation issued a warning to climbers of
an increased chance of eruption from the crater lake. Risks to
people entering the Summit Hazard Zone within 2km of Crater Lake
are assessed to be higher than normal, due to an increase in gas
emission. The alert level remains at Level One. Ruapehu, one of
New Zealand's most active volcanoes, is a complex stratovolcano
constructed during at least 4 cone-building episodes dating back
to about 200,000 years ago. The 110 cu km dominantly andesitic
volcanic massif is elongated in a NNE-SSW direction and is
surrounded by another 100 cu km ring plain of volcaniclastic
debris, including the Murimoto debris-avalanche deposit on the
NW flank. A series of subplinian eruptions took place at Ruapehu
between about 22,600 and 10,000 years ago, but pyroclastic flows
have been infrequent at Ruapehu. A single historically active
vent, Crater Lake, is located in the broad summit region, but at
least five other vents on the summit and flank have been active
during the Holocene. Frequent mild-to-moderate explosive
eruptions have occurred in historical time from the Crater Lake
vent, and tephra characteristics suggest that the crater lake
may have formed as early as 3000 years ago. Lahars produced by
phreatic eruptions from the summit crater lake are a hazard to a
ski area on the upper flanks and to lower river valleys. ).
Ruapehu Live cam
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PAPUA -
NEW GUINEA - Langila volcano
October
9th, 2009
As of the
8th of October, the Global Volcanism Network (GVN) has reported
that based on analyses of satellite imagery, the Darwin VAAC
reported that on 30 September an ash plume from Langila drifted
260 km NW at an altitude of 4.3 km (14,000 ft) a.s.l. On 5
October, a diffuse ash plume rose to an altitude of 3 km (10,000
ft) a.s.l. and drifted 185 km N. As of the 1st of October, GVN
reported that based on analyses of satellite imagery, the Darwin
VAAC reported that on 29 September an ash plume from Langila
rose to altitudes of 2.4-4.3 km (8,000-14,000 ft) a.s.l. and
drifted 75-220 km NW. Langila, one of the most active volcanoes
of New Britain, consists of a group of four small overlapping
composite basaltic-andesitic cones on the lower eastern flank of
the extinct Talawe volcano. Talawe is the highest volcano in the
Cape Gloucester area of NW New Britain. A rectangular,
2.5-km-long crater is breached widely to the SE; Langila volcano
was constructed NE of the breached crater of Talawe. An
extensive lava field reaches the coast on the north and NE sides
of Langila. Frequent mild-to-moderate explosive eruptions,
sometimes accompanied by lava flows, have been recorded since
the 19th century from three active craters at the summit of
Langila. The youngest and smallest crater (no. 3 crater) was
formed in 1960 and has a diameter of 150 m.
PAPUA-NEW GUINEA - Rabaul volcano
April
10th, 2010
RVO
reported on 9 April that deformation measurements at Rabaul
caldera during the previous 3-4 months showed an inflationary
trend with a total of 4 cm of uplift. During 2-8 April
seismicity was low and variable amounts of white vapor rose from
Tavurvur cone. As of the 17th of December, the Rabaul Volcano
Observatory (RVO) reported that activity from Rabaul caldera's
Tavurvur cone consisted of a few strong explosions towards the
beginning of the 4-10 December reporting period, and emissions
of gray ash afterwards. Diffuse white vapour was emitted during
quieter intervals. Ash plumes rose 1 km above the summit and
drifted SE towards Tokua and the Tokua airport, causing
suspension of some flights. Based on analyses of satellite
imagery, the Darwin VAAC reported that on 14 December an ash
plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and
drifted 35 km SE. Previously (RVO) reported that during 27
November-3 December dense white plumes and gray ash plumes rose
from Rabaul caldera's Tavurvur cone. Strong explosions produced
ash plumes that rose 1.5 km above the summit and showered the
flanks with lava fragments that were incandescent at night.
Shock waves rattled windows in the Kokopo area, about 20 km SE.
Incandescence from the summit crater was occasionally noted.
During 2-4 December, ash fell in Rabaul town (3-5 km NW) and
other villages downwind. Based on analyses of satellite imagery,
the Darwin VAAC reported that during 5 and 7-8 December ash
plumes rose to an altitude of 2.4 km (8,000 ft) a.s.l. and
drifted 45-55 km E. As of the 3rd of December, the Rabaul
Volcano Observatory (RVO) reported that during 20-26 November
thick white plumes and gray ash plumes rose from Rabaul
caldera's Tavurvur cone. Strong explosions produced ash plumes
that rose 1.5 km above the summit and showered the flanks with
lava fragments that were incandescent at night. Shock waves
rattled windows in the Kokopo area, about 20 km SE.
Occasionally, incandescence from the summit crater was noted. As
of the 22nd of October, the Rabaul Volcano Observatory (RVO)
reported that based on analyses of satellite imagery, the Darwin
VAAC reported that on 15, 18, and 20 October ash plumes from
Rabaul caldera's Tavurvur cone rose to altitudes of 2.7-3 km
(9,000-10,000 ft) a.s.l. and drifted 25-85 km NW, W, and NE.
As of the
15th of October, the Rabaul Volcano Observatory (RVO) reported
that during 2-8 October gray ash plumes from Rabaul caldera's
Tavurvur cone rose 2 km above the crater. Ashfall was reported
in Rabaul town (3-5 km NW) and surrounding areas. Incandescence
from the summit crater was occasionally visible. Based on
analyses of satellite imagery, the Darwin VAAC reported that on
9 October an ash plume rose to an altitude of 2.4 km (8,000 ft)
a.s.l. and drifted 75 km NW. As of the 24th of September, the
Rabaul Volcano Observatory (RVO) reported that during 11-17
September gray ash plumes from Rabaul caldera's Tavurvur cone
rose 1.5 km above the crater. Ashfall was reported in Rabaul
town (3-5 km NW) and surrounding areas. Occasionally,
incandescence from the summit crater was seen at night, and
incandescent lava fragments were ejected from the crater.
Rumbling and roaring noises were reported. Several strong
explosions occurred on 11, 16, and 17 September, but were few or
absent on other days. Based on analyses of satellite imagery,
the Darwin VAAC reported that during 21-22 September ash plumes
rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted
65-110 km NW.
The low-lying
Rabaul caldera lies on the tip of the Gazelle Peninsula at the
NE end of New Britain.
PAPUA -
NEW GUINEA - Karkar volcano
November 28th, 2009
As of the
28th of November, latest information showed that it is clear
that whatever it was that caused Darwin VAAC to report a major
eruption at Karkar volcano , it was not in fact an eruption. As
of the 25 th of November, according Darwin Volcanic Ash Advisory
Centre (VAAC) a possible significant eruption of Karkar volcano
in Papua New Guinea occured (unconfirmed information). The first
advisory was issued at 08:39 UTC and reported eruption with
eruptive plume to at least 10,000 metres altitude (?). More
recent advisories (the latest at the time of posting, issued at
20:57 UTC), reported ash to 13,700 metres altitude. A magnitude
5.1 earthquake hit 90 km SSE of Karkar volcano 7.5 hours before
the eruption. No other information on this possible eruption
appears to be available at the moment. Details as soon as
possible. Karkar (1839 m) is a 19 x 25 km wide, forest-covered
island that is truncated by two nested summit calderas. The
5.5-km-wide outer caldera was formed during one or more
eruptions, the last of which occurred 9000 years ago. The
eccentric 3.2-km-wide inner caldera was formed sometime between
1500 and 800 years ago. Parasitic cones are present on the
northern and southern flanks of basaltic-to-andesitic Karkar
volcano; a linear array of small cones extends from the northern
rim of the outer caldera nearly to the coast. Most historical
eruptions, which date back to 1643, have originated from Bagiai
cone, a pyroclastic cone constructed within the steep-walled,
300-m-deep inner caldera. The floor of the caldera is covered by
young, mostly unvegetated andesitic lava flows. last knows
eruption occured in 1979.
************************************************************************************************************
TONGA -
Hunga Ha'apai islands
March
22nd, 2009
Local
pilot reported that at 1015 on 21 March the island was covered
by weather clouds, the crater was not visible, and there was no
vertical plume; haze was again below an inversion layer at 1.5
km altitude. No
eruptions were seen during the 15 minutes the island was visible
on the return flight around 1250. However, steaming continued,
with the plume rising to 1.8 km altitude. A new eruptive episode
was reported by Tongatapu airport observers at 1409 on 21 March
that sent an ash plume 800 m high. As of the 20th of
March,Wellington VAAC reported that eruptive activity at Hunga
Tonga-Hunga Ha'apai appears to have declined somewhat over the
last 12 hours. The VAAC advisory, based on pilot observations
and satellite imagery, reported no more active eruptions
steaming 1800 metres high, with white and wispy ash haze
extending to large areas ENE blw 5000ft [below 1500 metres]‘. An
earlier advisory (17:58 GMT - 19th March) reported frequent
eruptions and ash clouds to FL130 (13000 feet, 4000 metres),
with a plume extending 300 miles (480 kilometres) ENE. At 01:30
GMT today NASA's Aqua satellite captured a MODIS image which
showed only a small plume extending less than 10 kilometres ENE
of the volcano (from the NASA MODIS). As of the 18th of March,
the Global Volcanism Network (GVN) reported that a new eruption
in Tonga was documented on 16 or 17 March by observers flying
near the area. Preliminary description and coordinates suggest
that the eruption is from Hunga Tonga-Hunga Ha'apai islands (
approx. coordinates S 20º 27' 73? W 175º 25' 61? given by the
pilots). Residents said the steam and ash column first appeared
on Monday morning, after a series of earthquakes were felt in
the capital, Nuku'alofa. Press reported that spectacular columns
spewed out of the sea about 6 miles (10 kilometers) from the
southwest coast off the main island of Tongatapu. According to
Tonga GeologicaI Service it was likely the underwater eruption
was taking place to the west of the low-lying twin volcanic
islands of Hunga Tonga and Hunga Ha'apai, within sight of
Nuku'alofa.
Preliminary report and photos.The small islands of Hunga
Tonga and Hunga Ha'apai cap a large seamount located about 30 km
SSE of Falcon Island. The two linear andesitic islands are about
2 km long and represent the western and northern remnants of a
the rim of a largely submarine caldera lying east and south of
the islands. Hunga Tonga and Hunga Ha'apai reach an elevation of
only 149 m and 128 m above sea level, respectively, and display
inward-facing sea cliffs with lava and tephra layers dipping
gently away from the submarine caldera. A rocky shoal 3.2 km SE
of Hunga Ha'apai and 3 km south of Hunga Tonga marks the most
prominent historically active vent. Submarine eruptions were
reported here in 1912 and 1937 and from a fissure 1 km SSE of
Hunga Ha'apai in 1988.
TONGA - West Mata submarine volcano
May 20th, 2009
In early
May, scientists aboard a NOAA Vents Program rapid-response
vessel, the R/V Thompson, traveled to the Lau-Tonga region to
inspect the sea floor after strong indications of eruptive
activity had been detected during a November 2008 expedition. On
6 and 7 May, team members used the Jason 2 ROV to observe
eruptions from two vents of West Mata, a small submarine
volcanic cone in the northeast Lau Basin, about 200 km SW of
Samoa. Explosive activity occurred from one end of a 5-m-long
fissure at Hades vent, at a depth of 1,208 m, while pillow lavas
erupted from the other end of the fissure. Glowing bubbles up to
a meter in diameter also issued from the fissure. The Prometheus
vent, a cinder cone located near the summit and about 100 m N of
Hades, erupted explosively with nearly continuous lava fountains
that ejected tephra into the water. Both vents were often
obscured by sulfur gas emissions, but incandescence was visible
for minutes at a time. West Mata, a submarine volcano rising to
within 1174
m of the sea surface, is located in the northeast Lau Basin at
the northern end of the Tonga arc. It was discovered during a
2008 NOAA Vents Program expedition to be producing hydrothermal
plumes consistent with a recent eruption. A return visit in May
2009 documented explosive and effusive activity from two closely
spaced vents, one at the summit, and the other on the SW rift
zone. (from GVN/GVP)
***********************************************************************************************************************
Mariannes islands - Pagan volcano
April
17th , 2009
As of the
16th of April, the CNMI Emergency Management Office has elevated
its volcano alert level after receiving reports of increased
volcanic activity on Pagan Island in the Northern Islands. In a
statement issued yesterday, EMO reported they first received a
call regarding the volcanic activity from Pagan at 6pm Wednesday
15th of April. EMO consulted with the U.S. Geological Services
and the National Weather Service in Guam, which observed a plume
of black and white, possible ash and gas emitting from the
volcano on Pagan. EMO said it contacted a vessel named MV San
Antonio that was on Pagan at the time to verify the situation.
According to the captain of the vessel, the plume was about
twice the size of Mt. Pagan. Pagan Island, the largest and one
of the most active of the Mariana Islands volcanoes, consists of
two stratovolcanoes connected by a narrow isthmus. Both North
and South Pagan stratovolcanoes were constructed within
calderas, 7 and 4 km in diameter, respectively. The 570-m-high
Mount Pagan at the NE end of the island rises above the flat
floor of the northern caldera, which probably formed during the
early Holocene. South Pagan is a 548-m-high stratovolcano with
an elongated summit containing four distinct craters. Almost all
of the historical eruptions of Pagan, which date back to the
17th century, have originated from North Pagan volcano. The
largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated
island. Last know eruption occured in 2006.
***********************************************************************************************************
ANTARCTICA - Erebus Volcano
March
1st, 2009
As of the
1st of March 2009, the Mt. Erebus Volcano Observatory (MEVO)
reported that Antarctica's Mt. Erebus continues with a molten
lava lake and vapour emissions. It may be covered with glaciers,
but they do little to cool the volcano's molten core. As of the
1st of August 2007, the Mt. Erebus Volcano Observatory (MEVO)
was reported that Mt. Erebus has frequent Strombolian eruptions.
Infrequent ash eruptions. Rare lava flows confined to inner
crater. Notable features are: Persistent convecting phonolite
lava lake. Persistent low-level eruptive activityAccording to
the Mt. Erebus activity log, several "small- to medium-sized"
eruptions occurred during 12-18 October 2005, with a "very
large" eruption occurring on 14 October. The eruption sizes were
based on comparisons of seismic data for known Erebus eruptions.
Mt. Erebus, the southern most volcano in the world, still
continues to be the most active volcano in Antarctica. Mt.
Erebus (3794 meters above sea level) is classified as a
polygenetic stratovolcano. The composition of the current
eruptive activity on Mt. Erebus is anorthoclase-phyric
tephriphonolite and phonolite, which constitute the bulk of
exposed lava flow on the volcano. The oldest eruptive products
from Mt. Erebus consist of relatively undifferentiated and
non-viscous basanitic lavas that form the low, broad platform
shield of the Erebus edifice. Slightly younger basanites and
phonotephrite lavas crop out on Fang Ridge, an eroded remnant of
an early Erebus volcano and at other isolated locations on the
flanks of the Mt. Erebus edifice. Lava flows of more viscous
phonotephrite, tephriphonolite and trachyte are erupted after
the basanites. The upper slopes of Mt. Erebus are dominated by
steeply dipping (~30°) tephriphonolite lava flows with large
scale flow levees. A conspicuous break in slope at approximately
3200 meters is a summit plateau representing a caldera. The
summit caldera itself is filled with small volume
tephriphonolite and phonolite lava flows. In the center of the
of the summit caldera is a small, steep-sided cone composed
primarily of decomposed lava bombs and a lag deposit of
anorthoclase crystals. It is within this summit cone that the
active lava lake continuously degasses and periodically erupts.
Mt. Erebus located on Ross Island, Antarctica is the world’s
southern-most active volcano. Discovered in 1841 by James Ross,
it is one of only a very few volcanoes in the world with a
long-lived (decades or more) lava lake. Scientific research,
sponsored by the U.S. National Science Foundation (NSF) since
began the early 1970’s had included basic study of the petrology
and geophysics of the volcano, the eruptive history, activity
and degassing behavior of the lava lake, and the overall impact
of the volcano on the Antarctica and global environment.
Research on Mt. Erebus has been primarily conducted by
scientists in the Department of Earth and Environmental Science
and the Bureau of Geology and Mineral resources at the New
Mexico Institute of Mining and Technology. Information from :
MEVO -
Live cam link
************************************************************************************************************
VANUATU
- Gaua - Mt. Garet volcano
April
22nd, 2010
As of the
22nd of April, the Vanuatu Geohazards Observatory (VGO) reported
that the situation at Gaua is worsening. Ash from the current
eruption is contaminating water and food supplies on the island.
Authorities are planning on evacuating 3,000 people from the
island if the eruption that started in 2009 gets worse, but
there has already been significant ash fall, mudflows and
explosions. As of the 7th of April, the analysis of data
collected from the monitoring network of Gaua volcano since
October 2009 indicates the existence of volcanic tremor. The OMI
satellite images also show the abundance of gases emitted from
this volcano daily. Field observations reported by the
Geohazards officer in Gaua confirmed significant change of
activity with ticker and higher emissions of ash columns. Since
last week (end of march/beginning of April 2010) the ash plumes
height dwell between 7000 and 10000
feet every day. Field reports also stated that the explosion
sounds could be heard from the villages daily. Moreover,
starting from the 3rd of April 2010 the volcanic bombes
projections from Gaua volcano could be observed from all the
coastal villages from the north to the south of the island with
reports of the ashfall.
As of the 29th of January, Geo-hazards Vanuatu reported that the
volcanic activity on Gaua has changed significantly during the
month of January. More gas has been emitted since 16 January,
followed by multiple explosions with thicker and darker ash
plume. This plume of ash and gas was being expelled to about
more than 3000 meters high and carried by the wind to
surrounding villages in the south and west. Strong strombolian
activity was evident on the 24th of January 2010 as villagers
were able to observe its projections. These signs indicate that
the level of magma is rising. Very strong explosions have been
heard and seen from the coastal villages of East Gaua this
morning, January 29th 2010. Due to the current activity, the
level of water and the rate of river flow from the waterfall and
outlets were observed to have risen from 20 to 30cm since
January 22nd. This occurrence is possibly due to the disturbance
within the Lake Letas which is feeding the river due to the
rising activity. Water from water thanks in the eastern coast is
becoming acid from the acid rains. This means that there can be
greater threats posed given the occurrence of volcanic
explosions. As of the 13th of January 2010, Geo-Hazards Vanuatu
reported that the continuous ash emission activity of the Gaua
volcano that begun on Monday 14th December 2009 with the
significant emissions of ashes is still ongoing. This was
accompanied by explosions heard from the villages on the 29th of
December 2009. This eruptive phase is different from previous
activities with thicker and darker plumes (see photos). These
changes reflect the evolution of the source (alimentation) of
the volcano. Ash falls continue to persist in the western part
of Gaua and with the changes in the direction of the wind; it is
possible that ash falls may also be experienced in the eastern
part of the island. Chemical analysis of the ashes that fell and
were collected in October, which was carried out by York
University in England, have indicated that there is a high
concentration of chemicals which are hazardous to the human
health within these ash particles from Gaua. More analysis will
be coming up on the new deposits. The latest OMI satellite
images clearly show the persistence of significant flux of gases
being emitted from Gaua volcano. As of the 27th of November, the
Geo-hazards Officer who is responsible for the Gaua volcano
monitoring works on Gaua has confirmed the big explosion of the
Gaua volcano in November 18th 2009 at 2pm. This explosion has
been followed by very thick and high emissions of ash columns
that were covering the areas exposed to trade winds in the West.
Volcano-seismic data recorded by the monitoring station based in
east Gaua shows the increase in volcano activity signals
starting from October 25th. Until present, the data shows that
the activity of Gaua volcano remains significant. With this
trend, it is recommended that the Alert Level of the volcano be
remained at level 2 according to the Vanuatu volcano Alert
Levels (VVAL) while Geo-hazards is carrying out a very close
monitoring with the IGNS counterparts. The danger persists in
the red and yellow colour zones of the hazard map, especially
the risks of ash falls and mudflows in the zone 1, zone 2 and
zone 3 of the revised hazards map. According to news release
more than 300 villagers were evacuated on Thursday 26th of
November after an eruption started from the volcano and spewing
smoke and ash onto the island and villages around. Residents
were loaded onto fishing boats and shipped to the far side of
Gaua island after the volcano. Also, according to Vanuatu's
National Disaster Management Office they're evacuating people to
the other side of the island. The Red Cross is providing water
containers and purification tablets for the villagers, who have
been hit by respiratory problems and diarrhoea caused by the
volcano's pungent sulphur fumes. The evacuees will have to stay
away from their villages until the volcano subsides, he said.
The area has been put on the second highest alert level. No more
information was reported directly from VGO yet. Previously, as
of the 13th of October
VGO
(Vanuatu Geohazards Observatory) latest bulletin reported that
after the assessment of the geohazards team on Gaua volcano from
3-7 October 2009, it is confirmed that Mont Garet volcano is
going through an eruptive phase starting from the 27th of
September 2009. Seismic records of the seismic station installed
on Gaua show that many explosions occurred on Gaua volcano.
Volcanic gas flux measurements on October 3rd show that 3000
tons of sulfuric dioxide is released from this volcano each day,
this means that a significant quantity of magma is degassing
from Gaua volcano. The lake letas, localised close to the Mont
Garet volcano, is one of the biggest crater lake of South
Pacific, its volume reachs 800 million cubic meters which is
drained out through the river of the Waterfall. With this
information, the Alert level of this volcano is now raised to
Level 2 on the Vanuatu Volcano Alert Level (VVAL). This means
that this volcano is going through a minor eruption. It is not
recommended to approach the volcano. The danger remains in the
red zone area on the hazard map including all the river outlets
in Gaua, especially the river of waterfall (see Hazard map).
With the related alert level, a level of response from the
community is required (see attached Community Disaster response
plan). Geohazards is doing its best with the limited resources
available to continue monitoring this volcano. As of the 6th of
october, local New Zealand information reported that
volcanologists in Vanuatu are closely monitoring the Gaua
volcano to consider whether to move its alert to level two. A
senior vulcanologist at the geohazards department, Douglas
Charley, reported his team has recorded more activity since last
night. Very late yesterday the team started to observe an
increase of a high volcanic high frequency. The level remains at
one and the team will be trying to observe this until the next
48 hours. If activity will increasing further, Alert level will
be putting to level two.Douglas Charley says they have one
monitoring station in the field, but are now requesting more to
get more reliable data. As of the 1st of october 2009, the
national authorities of the republic of Vanuatu from the the
Vanuatu Department of Geology Mines and Water Resources have
issued an alert (at the lowest level of one , on a scale of 1-5)
for Gaua volcano island, also known as Santa Maria Island
located the northern part of the archipelago. The volcano has
been showing signs of activity for the last two weeks, with
accounts of repeated explosions and ash and gas emission. Local
inhabitants have reported large quantities of smoke being
produced by the volcano, a strong smell of sulphur and some
contamination of local water and food supplies. About 2000
people live on the island. The roughly 20-km-diameter Gaua
Island, also known as Santa Maria, consists of a
basaltic-to-andesitic stratovolcano with an 6 x 9 km wide summit
caldera. Small parasitic vents near the caldera rim fed
Pleistocene lava flows that reached the coast on several sides
of the island; several littoral cones were formed where these
lava flows reached the sea. Quiet collapse that formed the
roughly 700-m-deep caldera was followed by extensive ash
eruptions. Construction of the historically active cone of Mount
Garat (Gharat) and other small cinder cones in the SW part of
the caldera has left a crescent-shaped caldera lake. The
symmetrical, flat-topped Mount Garat cone is topped by three pit
craters. The onset of eruptive activity from a vent high on the
SE flank of Mount Garat in 1962 ended a long period of dormancy.
Last know significative activity occures in 1982 (GVN/GVP)
VANUATU
- Ambrym volcano
April
2nd, 2009
As of 2nd
of April based on information from the Port Vila airport tower,
the Wellington VAAC reported that on 25 March an ash plume from
Ambrym rose to an altitude of 2.1 km (7,000 ft) a.s.l. and
drifted about 55 km S. The next day, a pilot reported that
"smoke" rose to an altitude of 2.4 km (8,000 ft) a.s.l. Ash was
not identified on satellite imagery. Ambrym, a large basaltic
volcano with a 12-km-wide caldera, is one of the most active
volcanoes of the New Hebrides arc. A thick, almost exclusively
pyroclastic sequence, initially dacitic, then basaltic, overlies
lava flows of a pre-caldera shield volcano. The caldera was
formed during a major Plinian eruption with dacitic pyroclastic
flows about 1900 years ago. Post-caldera eruptions, primarily
from Marum and Benbow cones, have partially filled the caldera
floor and produced lava flows that ponded on the caldera floor
or overflowed through gaps in the caldera rim. Post-caldera
eruptions have also formed a series of scoria cones and maars
along a fissure system oriented ENE-WSW. Eruptions have
apparently occurred almost yearly during historical time from
cones within the caldera or from flank vents. However, from 1850
to 1950, reporting was mostly limited to extra-caldera eruptions
that would have affected local populations.
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Bezymianny volcano (H.Gaudru) |
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VANUATU -
Yasur volcano ( Tanna island)
March 10th,
2010
Following
the observations of the Geo-hazards team on in March 8th 2010
and the analysis of the volcano-seismic data recorded by the
monitoring network of this volcano, it is confirmed that the
activity of this volcano is increasing since January 2010, as
indicated in the satellite images. This is also proven by the
activity of all the three active vents and the recent volcanic
bombs that fell on visitors' observation path. Under these
circumstances, the Alert Level for Yasur volcano is raised to
LEVEL 2 according to the Vanuatu Volcanoes Alert Levels (VVAL) .
This means that eruptions are moderate and danger close to the
volcano, within parts of Red Zone of the Hazard map. Thus
approaching the volcano could be dangerous; it would be safer to
view the yasur volcano from the parking area to avoid the
volcano impact. Visitors and tourism agencies are advised to
consider this information until the next alert is released.
Previously, as of the 12th of August 2009, John Seach reported
that eruptive activity continues at Yasur volcano in Vanuatu.
During a visit to the volcano from 1-3 August, John Seach
observed Strombolian explosions ejecting lava to a height of 300
m above the vent. Ash emissions were lower than normal, which
allowed good views into the crater. One vent was active in the
northern crater, and two vents active in the southern crater. As
of the 1st of March 2009, Yasur volcano continues to erupt many
times per hour as it has done so for at least 800 years.
Previously, as of the 1st of October, mainly from reports from
colleague, John Seach of Australia, reports that Yasur is still
currently erupting. Strombolian and mild Vulcanian eruptions
continue at Yasur volcano. Three main active vents are visible
inside the summit crater. Incandescent lava explosions reached
250 m above the crater, accompanied by loud explosions.
Projectiles were observed falling on the crater rim, 170 m from
the vents. As of the 9th of April 2008, mainly from
reports of John Seach , reported that a major earthquake
(magnitude 7.6) hit southern Vanuatu today at 2346hrs local
time. The earthquake was located east of the South New Hebrides
Trench and 97 km SW of Yasur volcano. The Joint Australian
Tsunami Warning Centre said there was no tsunami threat. The
main earthquake was preceded by a large and two medium sized
earthquakes; magnitude 6.5, 5.9, and 4.9. Yasur is the closest
active volcano to the earthquake epicentre and is currently
erupting. As of the 1st of April, activity has been almost
continuous at the Yasur volcano in Vanuatu. As of the 26th of
March, the Darvin Volcanic Ash Advisory (DVAAC) has reported
that Strombolian and mild Vulcanian eruptions continue at Yasur
volcano. Three main active vents are visible inside the summit
crater. Incandescent lava explosions reached 250 m above the
crater, accompanied by loud explosions. On 7-8th March, ash
emissions increased at Yasur producing ashfall over villages
within 4 km of the crater. Projectiles were observed falling on
the crater rim, 170 m from the vents. Previous information from
IRD reported that a new cycle of important activity has began at
the end of June 2004. Its the fifth cycles of strong activity
since the beginning of the permanent monitoring in 1993. This
activity produced important ashfalls ( several millimeters as
far 4 km distance of the volcano). Main eruptive activity
occurred from the Crater A with strombolian explosions. Height
has been estimated estimated to some 300 m high above the crater
rim. Sulphur dioxide measurements (SO2) made between 11-17 of
July 2004 with mini Doas spectrometer reaches average values of
1000 tonnes per day (500 tonnes per day in April 2004).
Information from Michel Lardy (IRD Noumea) and DGMWR (Vanuatu)
Yasur is one of the world's most active volcanoes. Previous
informations from IRD reported that a new cycle of important
activity has began at the end of June 2004. Its the fifth cycles
of strong activity since the beginning of the permanent
monitoring in 1993. This activity produced important ashfalls (
several millimeters as far 4 km distance of the volcano). Main
eruptive activity occured from the Crater A with strombolian
explosions. Height has been estimated estimated to some 300 m
high above the crater rim. Sulphur dioxyde measurements (SO2)
made between 11-17 of July 2004 with mini Doas spectrometer
reaches average values of 1000 tons per day (500 tons per day in
April 2004). Information from Michel Lardy (IRD Noumea) and
DGMWR (Vanuatu)Previous significative information (September
2002) reported an increasing level of activity at Yasur since
October 2001 and the volcanic quake of August 29, 2002 (about
3:00 pm local time), led local volcanologist to upgrade the
hazard rating to Alarm Level 3. Access to the volcano was
closed.The August 29 quake, magnitude 6 was strongly felt by the
inhabitants of the whole district around the volcano (White
Sands, Port Resolution, …). This was the first time since the
seismic station was installed in October 1992 that a shock of
such magnitude was recorded (see graphs below). Elders of the
Yasur district confirm that such a quake had not been
experienced within living memory.Two new seismological
monitoring stations are about to be installed, to complement the
existing alarm system installed 2 km from Yasur and the Isangel
station. At this time, evacuation of the roughly 6000
inhabitants of the district has not been considered. Information
bulletins will be broadcast by Radio Vanuatu to keep the
population concerned informed of new developments. Yasur's
activity follows a long volcanic history in the southeastern
part of the island , whose main phases, over approximately the
last 10,000 years, have produced: 1/ lava flows; 2/ extensive
glowing ash flows that covered the entire region from Kwamera to
Waisisi, and 3/ the construction of another small volcanic cone,
the Ombus. Yasur volcano lies over a large and shallow (less
than 10 km from the surface) magmatic chamber whose center is
located between Port-Resolution and Sulfur Bay; thus, the
possibility of a major eruption within a century or a millennium
cannot be ignored. Such an eruption, however, would be preceded
by numerous earthquakes. Should this happen, evacuation of the
local population toward the west coast, the central districts
and the north of the island would have to be carried out
rapidly. Informations from :M.Lardy (IRD Noumea)
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