GVP/USGS Weekly Volcanic Activity Report 2-8 January 2008

Kimberly Genareau <kgenarea@xxxxxxx> · Thu, 10 Jan 2008 12:05:26 -0700

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GVP/USGS Weekly Volcanic Activity Report
2-8 January 2008
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
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New Activity/Unrest: | Karkar, Papua New Guinea | Llaima, Chile |
Miyake-jima, Japan | Tungurahua, Ecuador

New Activity/Unrest

KARKAR Papua New Guinea 4.649°S, 145.964°E; summit elev. 1839 m

RVO reported that white vapor emissions from the Bagiai cone in
Karkar's inner caldera were observed by a visiting field team during
27-31 December. The resultant white vapor plume was also visible from
the mainland. Communities to the W and SW reported hearing roaring
noises associated with gas emissions. Images sent to RVO on 11
December indicated that the vegetation on the SE flank was completely
withered.

Geologic Summary. Karkar 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.

Source: Herman Patia, Rabaul Volcano Observatory

LLAIMA Chile 38.692°S, 71.729°W; summit elev. 3125 m

SERNAGEOMIN reported that seismic tremor coincided with the onset of
gas emissions and the ejection of pyroclastic material from Llaima on
1 January. Within a few hours, a Strombolian phase began. An increase
in volume of the Captrén River on the N flank was observed. On 2
January, small emissions of ash and gas (mainly steam) and three small
lahars on the N and W flanks were observed during an overflight.
Tremor also decreased and an explosion was observed. Based on pilot
reports and observations of satellite imagery, the Buenos Aires VAAC
reported that an ash plume rose to an altitude of 12.5 km (41,000 ft)
a.s.l. and drifted E on 2 January. A lava flow on the E flank was also
noted.

On 3 January, another overflight revealed that the explosion that
occurred on the previous day took place from an area high on the E
flank and not from within the crater. Emissions of gas and ash were
small and sporadic. The Buenos Aires VAAC reported that an ash plume
was visible on satellite imagery at an altitude of 3.7 km (12,000 ft)
a.s.l. and drifted NE.

Geologic Summary. Llaima, one of Chile's largest and most active
volcanoes, contains two historically active craters, one at the summit
and the other to the SE. The massive 3,125-m-high, glacier-covered
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 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 7,200
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.

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
http://www.sernageomin.cl/index.php,

Buenos Aires Volcanic Ash Advisory Center (VAAC)

http://www.ssd.noaa.gov/VAAC/OTH/AG/messages.html

MIYAKE-JIMA Japan 34.079°N, 139.529°E; summit elev. 815 m

Based on information from JMA, the Tokyo VAAC reported that an
eruption plume from Miyake-jima rose to an altitude of 1.2 km (4,000
ft) a.s.l. and drifted SE on 7 January.

Geologic Summary. The circular, 8-km-wide island of Miyake-jima forms
a low-angle stratovolcano that rises about 1100 m from the sea floor
in the northern Izu Islands about 200 km SSW of Tokyo. Parasitic
craters and vents, including maars near the coast and radially
oriented fissure vents, dot the flanks of the volcano. Frequent
historical eruptions have occurred since 1085 AD at vents ranging from
the summit to below sea level, causing much damage on this small
populated island. After a three-century-long hiatus ending in 1469,
activity has been dominated by flank fissure eruptions sometimes
accompanied by minor summit eruptions. A 1.6-km-wide summit caldera
was slowly formed by subsidence during an eruption in 2000; by October
of that year the crater floor had dropped to only 230 m above sea
level.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

IG reported that although visual observations were occasionally
limited due to cloud cover, ash-and-steam and ash plumes from
Tungurahua were seen and rose to altitudes of 5.5-8 km (18,000-26,200
ft) a.s.l. during 2-8 January. Plumes drifted NW and W. Ashfall was
reported in areas to the W and SW during 3-4 and 7-8 January.

On 1 January, ash emissions were continuous and incandescent blocks
rolled down the flanks. Roaring noises and "cannon shots" were heard,
and the ground and windows vibrated in areas to the NNE and NNW. On 3
January, the seismic network recorded a high number of explosions.
Some explosions caused acoustic waves similar to "cannon shots" that
vibrated windows in areas to the W and NW. These explosions ejected
incandescent blocks from the summit crater that rolled 500 m down the
flanks. On 4 January, "cannon shots" were again noted as far as 13 km
away; this caused large windows to vibrate in areas to the W and glass
to break in Puñapí. Explosions vibrated the ground in one town and
generated ash plumes that rose to an altitude less that 6 km (19,700
ft) a.s.l. During 5-8 January, roaring noises and "cannon shots"
continued; windows and floors vibrated as far as the Tungurahua
Observatory (OVT) in Guadalupe, about 13 km NW, on 6 January.

According to news articles, nearly 1,000 people were evacuated on 6
January to spend the night in evacuation shelters. They were allowed
to return to their villages in the daytime to tend to homes, crops,
and animals.

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 all originated from 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.

Sources: Instituto Geofísico-Escuela Politécnica Nacional
http://www.igepn.edu.ec/,

Associated Press http://www.dailymail.com/News/200801060110

Ongoing Activity

ANATAHAN United States 16.35°N, 145.67°E; summit elev. 790 m

The USGS reported that during 29 December-5 January 2008, low-level
steaming and sulfur dioxide emission from Anatahan were visible on
satellite imagery. Seismicity briefly increased on 2 January and then
diminished. A report suggested that the lake level in the E crater had
been dropping since September. The Volcanic Alert Level remained at
Advisory and the Aviation Color Code remained at Yellow.

Geologic Summary. The elongate, 9-km-long island of Anatahan in the
central Mariana Islands consists of large stratovolcano with a 2.3 x 5
km, E-W-trending compound summit caldera. The larger western caldera
is 2.3 x 3 km wide, and its western rim forms the island's 790-m high
point. Ponded lava flows overlain by pyroclastic deposits fill the
floor of the western caldera, whose SW side is cut by a fresh-looking
smaller crater. The 2-km-wide eastern caldera contained a steep-walled
inner crater whose floor prior to the 2003 eruption was only 68 m
above sea level. Sparseness of vegetation on the most recent lava
flows on Anatahan had indicated that they were of Holocene age, but
the first historical eruption of Anatahan did not occur until May
2003, when a large explosive eruption took place forming a new crater
inside the eastern caldera.

Source: Emergency Management Office of the Commonwealth of the Mariana
Islands and the US Geological Survey Hawaiian Volcano Observatory
http://volcano.wr.usgs.gov/cnmistatus.php

BULUSAN Philippines 12.770°N, 124.05°E; summit elev. 1565 m

According to a news article, at least seven minor earthquakes near
Bulusan during 6-7 January prompted authorities to enforce the
no-entry policy within the permanent danger zone, defined by a 4-km
radius around the volcano. The Alert Level remained at 1 (out of 5).

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: GMA News
http://www.gmanews.tv/story/75518/Minor-quakes-rock-Bulusan-Phivolcs-warns-vs-entry-into-4-km-radius

KILAUEA United States 19.421°N, 155.287°W; summit elev. 1222 m

Based on overflights and web camera views when weather permitted, HVO
reported that during 2-8 January activity from fissure segment D from
Kilauea's 21 July fissure eruption was concentrated at the
Thanksgiving Eve Breakout (TEB) shield and two satellitic shields to
the SE. Lava flows traveled S and stalled within 2.2 km SE of fissure
D. From 21 July 2007 to 4 January 2008, the Pu'u 'O'o cone contracted
about 0.45 m, based on interpretation of GPS data. Incandescent
flashes at the top of the TEB shield were visible during 4-6 January
and one short lava flow to the N was detected on 6 January. On 7
January, a lava pond was seen in a vent on top of the TEB shield
during an overflight. During 7-8 January, brief flashes and one lava
overflow at the top of the shield was seen on the web camera. Tremor
remained low below Pu'u 'O'o crater. A few small earthquakes were
located beneath the summit and along the S-flank fault.

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 of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.

Source: US Geological Survey Hawaiian Volcano Observatory

http://volcano.wr.usgs.gov/hvostatus.php

POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m

CENAPRED reported that emissions of steam-and-gas from Popocatépetl
were visible during 2-8 January. On 5 January, a steam-and-gas plume
with low ash content was reported. An altitude of the plume was
unknown due to cloud cover. About two hours later, CENAPRED received
reports of slight ashfall in Paso de Cortés, about 7.5 km N of the
summit.

Based on information from the Mexico City MWO and observations of
satellite imagery, the Washington VAAC reported that an ash plume rose
to an altitude of 7.3 km (24,000 ft) a.s.l. and drifted E, NE, and SE
on 5 January.

Geologic Summary. Popocatépetl, whose name is the Aztec word for
smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is
North America's second-highest volcano. Frequent historical eruptions
have been recorded since the beginning of the Spanish colonial era. A
small eruption on 21 December 1994 ended five decades of quiescence.
Since 1996 small lava domes have incrementally been constructed within
the summit crater and destroyed by explosive eruptions. Intermittent
small-to-moderate gas-and-ash eruptions have continued, occasionally
producing ashfall in neighboring towns and villages.

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED)
http://www.cenapred.unam.mx/cgi-bin/popo/reportes/ultrep.cgi,

Washington Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/messages.html

RABAUL Papua New Guinea 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that white plumes from Rabaul caldera's Tavurvur cone
were observed during 28 December-3 January. Incandescence at the
summit was noticeable at night and loud roaring noises were often
heard after rain.

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.

Source: Steve Saunders, Rabaul Volcano Observatory

SAKURA-JIMA Japan 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Sakura-jima on 2 and 7 January. Details of possible resultant ash
plumes were unknown.

Geologic Summary. 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.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html

SHIVELUCH Russia 56.653°N, 161.360°E; summit elev. 3283 m

KVERT reported that seismic activity at Shiveluch was slightly above
background levels during 28 December-4 January. Based on seismic
interpretation, ash plumes rose to an altitude of 5.8 km (19,000 ft)
a.s.l. during 28-31 December and on 1 and 3 January. Moderate
fumarolic activity was noted on 30 December and 2 January. Based on
observations of satellite imagery, a thermal anomaly was present in
the crater every day. The Level of Concern Color Code remained at
Orange.

Based on information from the KEMSD, the Tokyo VAAC reported that
eruption plumes rose to altitudes of 6.4 and 4.9 km (21,000 and 16,000
ft) a.s.l. on 4 and 6 January, respectively.

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 breached 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 (KVERT)

http://www.kscnet.ru/ivs/kvert/index_eng.php,

Tokyo Volcanic Ash Advisory Center (VAAC)

http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html

SOUFRIERE HILLS United Kingdom 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that fumarolic activity on the N and E flanks of the
Soufrière Hills lava dome continued during 28 December-8 January.
Active fumaroles were also noted in the Galway's area to the S of the
dome and W in the Gages Wall area. Occasional rockfalls were
restricted to the Tar River valley. Observations during an overflight
on 3 January confirmed that the lava dome morphology had not changed
since the previous reporting period. The Alert Level remained elevated
at 4 (on a scale of 0-5).

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 E, was formed during an eruption about 4,000
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.

Source: Montserrat Volcano Observatory

http://www.mvo.ms/

ST. HELENS United States 46.20°N, 122.18°W; summit elev. 2549 m

Data from deformation-monitoring instruments indicated that during 2-8
January lava-dome growth at Mount St. Helens continued. Seismicity
persisted at low levels, punctuated by M 1.5-2.5, and occasionally
larger, earthquakes. A new small spine was seen on top of the active
lobe during an overflight on 31 December. The spine was hot enough to
be snow-free and interpreted as confirmation that the dome continued
to grow. Clouds frequently inhibited visual observations.

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: Cascades Volcano Observatory

http://vulcan.wr.usgs.gov/Volcanoes/Cascades/

+++++++++++++++++++++++++++++++++++++
Sally Kuhn Sennert
SI/USGS Weekly Volcanic Activity Report Editor
Global Volcanism Program
http://www.volcano.si.edu/reports/usgs/
Smithsonian Institution, National Museum of Natural History
Department of Mineral Sciences, MRC-119
Washington, D.C., 20560
Phone: 202.633.1805
Fax: 202.357.2476

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