**********************************************************
GVP/USGS Weekly Volcanic Activity Report
24-30 January 2007
http://www.volcano.si.edu/reports/usgs/
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New Activity/Unrest: | Bulusan, Philippines
Ongoing Activity: | Fuego, Guatemala | Karymsky, Russia | Kilauea, USA |
Langila, Papua New Guinea | Rabaul, Papua New Guinea | Sangay, Ecuador |
Santa María, Guatemala | Shiveluch, Russia | Soufrière Hills, Montserrat
| St. Helens, USA | Suwanose-jima, Japan | Talang, Indonesia |
Tungurahua, Ecuador | Ubinas, Perú
New Activity/Unrest
BULUSAN Luzon, Philippines 12.770°N, 124.05°E; summit elev. 1,565 m
PHIVOLCS reported that an explosion from the summit of Bulusan on 24
January lasted about 10 minutes based on seismic interpretation.
Observation was inhibited due to cloud cover. Ashfall was reported from
areas SW.
Geologic Summary. Luzon's southernmost volcano, Bulusan, was constructed
within the 11-km-diameter dacitic Irosin caldera, which was formed more
than 36,000 years ago. A broad, flat moat is located below the prominent
SW caldera rim; the NE rim is buried by the andesitic Bulusan complex.
Bulusan is flanked by several other large intracaldera lava domes and
cones, including the prominent Mount Jormajan lava dome on the SW flank
and Sharp Peak to the NE. The summit of Bulusan volcano is unvegetated
and contains a 300-m wide, 50-m-deep crater. Three small craters are
located on the SE flank. Many moderate explosive eruptions have been
recorded at Bulusan since the mid-19th century.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
http://www.phivolcs.dost.gov.ph/
Bulusan Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0703-01=
Ongoing Activity
FUEGO Guatemala 14.47°N, 90.88°W; summit elev. 3,763 m
Based on a pilot report and information from INSIVUMEH, the Washington
VAAC reported that a diffuse plume from Fuego reached an altitude of 4
km (13,000 ft) a.s.l. and drifted NE. A hotspot over the crater was
visible on satellite imagery. INSIVUMEH reported that approximately
during 21-29 January, incandescent material was propelled up to 100 m
above the summit and incandescent blocks rolled about 500 m S and SW
down the flanks. During 26 and 29 January, incandescent blocks broke
away from lava-flow fronts and rolled S towards the source of the Ceniza
River.
Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is one of three large stratovolcanoes overlooking Guatemala's
former capital, Antigua. The scarp of an older edifice, Meseta, lies
between 3,763-m-high Fuego and its twin volcano to the N, Acatenango.
Construction of Meseta volcano continued until the late Pleistocene or
early Holocene, after which growth of the modern Fuego volcano continued
the southward migration of volcanism that began at Acatenango. Frequent
vigorous historical eruptions have been recorded at Fuego since the
onset of the Spanish era in 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.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e
Hidrologia (INSIVUMEH)
http://www.insivumeh.gob.gt/geofisica/boletin%20formato.htm,
Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html
Fuego Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1402-09=
KARYMSKY Kamchatka Peninsula, Russia 54.05°N, 159.43°E; summit elev. 1,536 m
Seismic activity at Karymsky was above background levels during 19-26
January, with 100-250 shallow earthquakes occurring daily. Ash plumes
may have reached altitudes of 3.5 km (11,500 ft) a.s.l. during 7-8
January. A thermal anomaly in the crater was detected during the
reporting period. The Level of Concern Color Code remained at Orange
<http://www.avo.alaska.edu/color_codes.php>.
Geologic Summary. Karymsky, the most active volcano of Kamchatka's
eastern volcanic zone, is a symmetrical stratovolcano constructed within
a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago.
Construction of the Karymsky stratovolcano began about 2,000 years
later. The latest eruptive period began about 500 years ago, following a
2,300-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. Most seismicity preceding Karymsky
eruptions has originated beneath Akademia Nauk caldera, which is located
immediately S of Karymsky volcano and erupted simultaneously with
Karymsky in 1996.
Source: Kamchatkan Volcanic Eruption Response Team
http://www.kscnet.ru/ivs/kvert/updates.shtml
Karymsky Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1000-13=
KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m
During 24-30 January, lava from Kilauea continued to flow from lava
deltas into the ocean at the East Lae'apuki, Kamokuna, and East
Ka'ili'ili entries. Incandescence was intermittently visible on the pali
and from several vents in Pu'u 'O'o's crater. Breakout lava from the
Campout flow advanced about 1.6 km per hour on 24 January. The USGS
field crew noticed several small breakouts of lava from the Campout flow
at the base of the pali that flowed E and burned trees near the
long-abandoned Royal Gardens subdivision. Tremor near Pu`u `O`o
increased to a moderate level.
Geologic Summary. Kilauea, one of five coalescing volcanoes that
comprise the island of Hawaii, is one of the world’s most active
volcanoes. Eruptions at Kilauea originate primarily from the summit
caldera or along one of the lengthy E and SW rift zones that extend from
the caldera to the sea. About 90% of the surface of Kilauea is formed by
lava flows less than about 1,100 years old; 70% of the volcano's surface
is younger than 600 years. The latest Kilauea eruption began in January
1983 along the E rift zone. This long-term ongoing eruption from Pu`u
`O`o-Kupaianaha has produced lava flows that have traveled 11-12 km from
the vents to the sea, paving broad areas on the S flank of Kilauea and
adding new land beyond the former coastline.
Source: US Geological Survey Hawaiian Volcano Observatory
http://volcano.wr.usgs.gov/hvostatus.php
Kilauea information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1302-01-
LANGILA New Britain Island, Papua New Guinea 5.53°S, 148.42°E; summit
elev. 1,330 m
During 16-26 January, eruptive activity at Langila's Crater 2 consisted
of continuous emissions of gray ash plumes that rose to altitudes of 2.3
km (7,600 ft) a.s.l. and drifted SE and NE. Fine ash fell on the flanks.
Occasional roaring noises were heard accompanying emissions.
Incandescence was observed at the summit.
Geologic Summary. Langila, one of the most active volcanoes of New
Britain, consists of a group of four small overlapping composite 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 N 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.
Source: Herman Patia, Rabaul Volcano Observatory
Langila Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0502-01=
RABAUL New Britain Island, Papua New Guinea 4.271°S, 152.203°E; summit
elev. 688 m
RVO reported that during 18-26 January, seismic activity at Rabaul
caldera's Tavurvur cone continued at low levels. On 24 and 27-30
January, emissions of steam and a small amount of ash produced plumes
that rose to a maximum altitude of 2.7 km (8,900 ft) a.s.l. and drifted
N, NE, and E. Roaring noises were occasionally audible. Based on
satellite imagery and information from RVO, the Darwin VAAC reported
that a small plume was visible on 30 January and drifted NE.
Geologic Summary. The low-lying Rabaul caldera on the tip of the Gazelle
Peninsula at the NE end of New Britain forms a broad sheltered harbor.
The outer flanks of the 688-m-high asymmetrical pyroclastic shield
volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km
caldera is widely breached on the E, where its floor is flooded by
Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul took
place as recently as 3,500 and 1,400 years ago. Three small
stratovolcanoes lie outside the northern and NE caldera rims.
Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on
the caldera floor near the NE and western caldera walls. Several of
these, including Vulcan cone, which was formed during a large eruption
in 1878, have produced major explosive activity during historical time.
A powerful explosive eruption in 1994 occurred simultaneously from
Vulcan and Tavurvur volcanoes and forced the temporary abandonment of
Rabaul city.
Sources: Herman Patia, Rabaul Volcano Observatory,
Darwin Volcanic Ash Advisory Centre
http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
Rabaul Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0502-14=
SANGAY Ecuador 2.03°S, 78.34°W; summit elev. 5,188 m
Based on information from Guayaquil MWO, the Washington VAAC reported
that an eruption from Sangay on 28 January produced an ash plume that
rose to an altitude of 6.4 km (21,000 ft) a.s.l.
Geologic Summary. The isolated Sangay volcano, located E of the Andean
crest, is the southernmost of Ecuador's volcanoes, and its most active.
It has been in frequent eruption for the past several centuries. The
steep-sided, 5,230-m-high glacier-covered volcano grew within
horseshoe-shaped calderas of two previous edifices, which were destroyed
by collapse to the E, producing large debris avalanches that reached the
Amazonian lowlands. The modern edifice dates back to at least 14,000
years ago. Sangay towers above the tropical jungle on the E side; on the
other sides flat plains of ash from the volcano have been sculpted by
heavy rains into steep-walled canyons up to 600 m deep. The earliest
report of an historical eruption was in 1628. More or less continuous
eruptions were reported from 1728 until 1916, and again from 1934 to the
present. The more or less constant eruptive activity has caused frequent
changes to the morphology of the summit crater complex.
Source: Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html
Sangay Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1502-09=
SANTA MARÍA Guatemala 14.756°N, 91.552°W; summit elev. 3,772 m
Based on a pilot report and information from INSIVUMEH, the Washington
VAAC reported that a diffuse plume from Santa María's Santiaguito
lava-dome complex reached an altitude of 4.3 km (14,000 ft) a.s.l. on 24
January. A diffuse plume drifted SW on 30 January. INSIVUMEH reported
that explosions produced minor ashfall on 25, 26, and 29 January.
Block-and-ash avalanches descended the SW flank of Caliente Dome on 25
and 29 January.
Geologic Summary. Symmetrical, forest-covered Santa María volcano is one
of a chain of large stratovolcanoes that rises dramatically above the
Pacific coastal plain of Guatemala. The stratovolcano has a
sharp-topped, conical profile that is cut on the SW flank by a large,
1-km-wide crater, which formed during a catastrophic eruption in 1902
and extends from just below the summit to the lower flank. The renowned
Plinian eruption of 1902 followed a long repose period and devastated
much of SW Guatemala. The large dacitic Santiaguito lava-dome complex
has been growing at the base of the 1902 crater since 1922. Compound
dome growth at Santiaguito has occurred episodically from four
westward-younging vents, accompanied by almost continuous minor
explosions and periodic lava extrusion, larger explosions, pyroclastic
flows, and lahars.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e
Hidrologia (INSIVUMEH)
http://www.insivumeh.gob.gt/geofisica/boletin%20formato.htm,
Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html
Santa María Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1402-03=
SHIVELUCH Kamchatka Peninsula, Russia 56.653°N, 161.360°E; summit elev.
3,283 m
Activity at Shiveluch continued above background levels during 19-26
January, with over 120 shallow earthquakes occurring daily. Based on
seismic interpretation and observation and video data, gas-and-ash
plumes rose to 5.5 km (18,000 ft) a.s.l. and avalanches occurred
throughout the reporting period. Plumes drifted W and NW. Fumarolic
activity from the SW flank was noted on 25 January. A large thermal
anomaly was visible on satellite imagery. Based on satellite imagery,
the Tokyo VAAC reported that ash plumes rose to an altitude of 4.6 km
(15,000 ft) a.s.l. on 28 and 29 January and drifted SE.
Geologic Summary. The high, isolated massif of Shiveluch volcano (also
spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group and forms one of Kamchatka's largest and most active
volcanoes. The currently active Molodoy Shiveluch lava-dome complex was
constructed during the Holocene within a large horseshoe-shaped caldera
formed by collapse of the massive late-Pleistocene Strary Shiveluch
volcano. At least 60 large eruptions of Shiveluch have occurred during
the Holocene, making it the most vigorous andesitic volcano of the
Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most
recently in 1964, have produced large debris avalanches whose deposits
cover much of the floor of the breached caldera. During the 1990s,
intermittent explosive eruptions took place from a new lava dome that
began growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.
Sources: Kamchatkan Volcanic Eruption Response Team
http://www.kscnet.ru/ivs/kvert/updates.shtml,
Tokyo Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
Shiveluch Information from the Global Volcanism Program
http://www.volcano.si.edu/gvp/world/volcano.cfm?vnum=1000-27=
SOUFRIÈRE HILLS Montserrat, West Indies 16.72°N, 62.18°W; summit elev.
1,052 m
During 24-30 January, measurable activity at Soufrière Hills remained
low. Based on satellite imagery, information from MVO, and a pilot
report, the Washington VAAC reported that ash plumes were visible during
26-27 January. The plumes were likely a result of rockfall activity. On
28 January, a large pyroclastic flow traveled down the Tar River Valley
and reached the sea.
Geologic Summary. The complex, dominantly andesitic Soufrière Hills
volcano occupies the southern half of the island of Montserrat. The
summit area consists primarily of a series of lava domes emplaced along
an ESE-trending zone. English's Crater, a 1-km-wide crater breached
widely to the east, was formed during an eruption about 4000 years ago
in which the summit collapsed, producing a large submarine debris
avalanche. Block-and-ash flow and surge deposits associated with dome
growth predominate in flank deposits at Soufrière Hills. Non-eruptive
seismic swarms occurred at 30-year intervals in the 20th century, but
with the exception of a 17th-century eruption that produced the Castle
Peak lava dome, no historical eruptions were recorded on Montserrat
until 1995. Long-term small-to-moderate ash eruptions beginning in that
year were later accompanied by lava-dome growth and pyroclastic flows
that forced evacuation of the southern half of the island and ultimately
destroyed the capital city of Plymouth, causing major social and
economic disruption.
Sources: Montserrat Volcano Observatory http://www.mvo.ms/,
Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html
Soufrière Hills Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1600-05=
ST. HELENS Washington, USA 46.20°N, 122.18°W; summit elev. 2,549 m
Data from deformation-monitoring instruments showed that during 24-30
January, a spine on the lava dome at Mount St. Helens continued to grow.
Seismicity continued at low levels, punctuated by M 1.5-2.5 and
occasionally larger earthquakes.
Geologic Summary. Prior to 1980, Mount St. Helens formed a conical,
youthful volcano sometimes known as the Fuji-san of America. During the
1980 eruption the upper 400 m of the summit was removed by slope
failure, leaving a 2 x 3.5 km horseshoe-shaped crater now partially
filled by a lava dome. Mount St. Helens was formed during nine eruptive
periods beginning about 40-50,000 years ago, and has been the most
active volcano in the Cascade Range during the Holocene. The modern
edifice was constructed during the last 2,200 years, when the volcano
produced basaltic as well as andesitic and dacitic products from summit
and flank vents. Historical eruptions in the 19th century originated
from the Goat Rocks area on the N flank, and were witnessed by early
settlers.
Source: US Geological Survey Cascades Volcano Observatory
http://vulcan.wr.usgs.gov/Volcanoes/MSH/CurrentActivity/framework.html
St. Helens Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1201-05-
SUWANOSE-JIMA Ryukyu Islands, Japan 29.53°N, 129.72°E; summit elev. 799 m
Based on information from JMA, the Tokyo VAAC reported an eruption plume
from Suwanose-jima on 28 January. The altitude and direction of the
plume were not reported.
Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-jima
in the northern Ryukyu Islands consists of an andesitic stratovolcano
with two historically active summit craters. Only about 50 persons live
on the sparsely populated island. The summit of the volcano is truncated
by a large breached crater extending to the sea on the E flank that was
formed by edifice collapse. 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 around 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.
Source: Tokyo Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
Suwanose-jima Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0802-03=
TALANG Sumatra, Indonesia 00.98°S, 100.68°E; summit elev. 2,896 m
CVGHM lowered the Alert Level at Talang to 2 (on a scale of 1-4) on 27
January due to a reduction in seismic activity since 23 November 2006 to
24 January 2007. Gas plumes were present from the South Crater and the
Main Crater.
Geologic Summary. Talang, which forms a twin volcano with the extinct
Pasar Arbaa volcano, has two crater lakes on its flanks. The largest of
these is 1 x 2 km wide Danau Talang. No historical eruptions have
occurred from the summit of the volcano, which lacks a crater. All
historical eruptions from Gunung Talang volcano have involved
small-to-moderate 19th-century explosive activity originating from a
series of small craters in a valley on the upper NE flank.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)
http://www.vsi.esdm.go.id/portal/html/index.php
Talang Information from the Global Volcano Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0601-16=
TUNGURAHUA Ecuador 1.47°S, 78.44°W; summit elev. 5,023 m
During 24-30 January, visual observations of Tungurahua were limited due
to inclement weather. On 26 January, lahars affected the Pampas sector
and blocked the Baños - Penipe highway until the next day. Lahars were
also reported to the W in Bilbao, NNW in Mandur, and NW in la Hacienda.
Small lahars to the W were reported on 28 January and a steam plume was
visible on 29 January.
Geologic Summary. The steep-sided Tungurahua stratovolcano towers more
than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador’s
capital city, and is one of Ecuador's most active volcanoes. Historical
eruptions have been restricted to the summit crater. They have been
accompanied by strong explosions and sometimes by pyroclastic flows and
lava flows that reached populated areas at the volcano's base. The last
major eruption took place from 1916 to 1918, although minor activity
continued until 1925. The latest eruption began in October 1999 and
prompted temporary evacuation of the town of Baños on the N side of the
volcano.
Source: Instituto Geofísico-Escuela Poltécnica Nacional
http://www.igepn.edu.ec/
Tungurahua Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1502-08=
UBINAS Perú 16.355°S, 70.903°W; summit elev. 5,672 m
Based on pilot reports, the Buenos Aires VAAC reported continuous
emissions from Ubinas on 28 January. Ash plumes rose to 5.5 km (18,000
ft) a.s.l. and drifted SE.
Geologic Summary. A small, 1.2-km-wide caldera that cuts the top of
Ubinas, Peru's most active volcano, gives it a truncated appearance.
Ubinas is 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. Widespread plinian pumice-fall deposits from Ubinas include
some of Holocene age. 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.
Source: Buenos Aires Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/OTH/AG/messages.html
Ubinas Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1504-02
**+++++++++++++++++++++++++++++++++++++**
**Sally Kuhn Sennert**
**SI/USGS Weekly Volcanic Activity
Report Editor**
**Global Volcanism Program**
Smithsonian Institution
National Museum of Natural History MRC-119
Department of Mineral Sciences
Washington, D.C., 20560
http://www.volcano.si.edu/reports/usgs/index.cfm
Phone: 202.633.1805
Fax: 202.357.2476
<http://www.volcano.si.edu/reports/usgs/>++++++++++++++++++++++++++++++++++++++++++
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