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From: leonard78sp on 16 Sep 2009 17:07

  SI / USGS Weekly VolcanicActivityReport

Sally Kuhn Sennert - Weekly Report Editor
URL:http://www.volcano.si.edu/reports/usgs
 9 September - 15 September 2009


New Activity/Unrest:

| Langila, New Britain
| Mayon, Luzon
| Shiveluch, Central Kamchatka (Russia)

Ongoing Activity:

| Bagana, Bougainville
| Barren Island, Andaman Is
| Batu Tara, Komba Island (Indonesia)
| Chaitén, Southern Chile
| Dukono, Halmahera
| Fuego, Guatemala
| Kilauea, Hawaii (USA)
| Pacaya, Guatemala
| Popocatépetl, México
| Rabaul, New Britain
| Sakura-jima, Kyushu
| Santa María, Guatemala
| Slamet, Central Java (Indonesia)
| Suwanose-jima, Ryukyu Islands (Japan)

This page is updated on Wednesdays,
please see the GVP Home Page for news
of the latest significant activity.

The Weekly Volcanic Activity Report is a cooperative project between
the Smithsonian's Global Volcanism Program and the US Geological
Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday,
notices of volcanic activity posted on these pages are preliminary and
subject to change as events are studied in more detail. This is not a
comprehensive list of all of Earth's volcanoes erupting during the
week, but rather a summary of activity at volcanoes that meet criteria
discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports on various volcanoes are
published monthly in the Bulletin of the Global Volcanism Network.

Note: Many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active.
To obtain information about the cited articles that are no longer
available on the Internet contact the source.

New Activity/Unrest

LANGILA New Britain 5.525°S, 148.42°E; summit elev. 1330 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 12 September an ash plume from Langila rose to an altitude of 3 km
(10,000 ft) a.s.l. and drifted 35 km W.

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.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Langila Information from the Global Volcanism Program

MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

PHIVOLCS reported that 11 earthquakes from Mayon were detected during
14-15 September. Steam plumes drifted NW and ENE and the sulfur
dioxide gas output decreased. Faint incandescence was observed at
night. On 15 September, three ash explosions produced a brownish plume
that rose no more than 700 m above the crater and drifted SW. The
Alert Level remained at 2 (on a scale of 0-5). The 7-km Extended
Danger Zone (EDZ) on the SE flank and the 6-km Permanent Danger Zone
(PDZ) in all other areas remained in effect.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises
to 2,462 m above the Albay Gulf, is the Philippines' most active
volcano. The structurally simple volcano has steep upper slopes that
average 35-40° and is capped by a small summit crater. The historical
eruptions of this basaltic-andesitic volcano date back to 1616 and
range from Strombolian to basaltic Plinian. Eruptions occur
predominately from the central conduit and have also produced lava
flows that travel far down the flanks. Pyroclastic flows and mudflows
have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often devastated populated lowland
areas. Mayon's most violent eruption, in 1814, killed more than 1,200
people and devastated several towns. Eruptions that began in February
2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of
people within a radius of 7 km from the summit in the SE and within a
6 km radius for the rest of the volcano.

Map

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Mayon Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 4-11 September seismic activity from
Shiveluch was above background levels. Analyses of satellite imagery
revealed a large daily thermal anomaly over the lava dome. Based on
interpretations of seismic data, ash plumes possibly rose to an
altitude of 4.2 km (13,800 ft) a.s.l. and hot avalanches occurred at
the lava dome. Gas-and-steam plumes rose to an altitude of 4 km
(13,100 ft) a.s.l. during 4-9 September. An ash plume was seen in
satellite imagery drifting 80 km E on 8 September.

On 11 September, KVERT reported strong explosions. Based on
interpretations of seismic data, ash plumes rose to an altitude
greater than 15 km (49,200 ft) a.s.l. The seismic network then
detected eight minutes of pyroclastic flows from the lava dome;
resulting plumes rose to an altitude of approximately 10 km (32,800
ft) a.s.l. The Level of Concern Color Code was raised to Red. Ten more
events characterized as ash explosions and either pyroclastic flows or
avalanches were detected. Cloud cover prevented visual observations.
Seismicity decreased during 11-12 September, and indicated that ash
plumes rose to altitudes of 4.5-6.5 km (14,800-21,300 ft) a.s.l. The
Level of Concern Color Code was lowered to Orange.

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. Intermittent
explosive eruptions began in the 1990s from a new lava dome that began
growing in 1980. The largest historical eruptions from Shiveluch
occurred in 1854 and 1964.

Map

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Shiveluch Information from the Global Volcanism Program

Ongoing Activity

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 12-13 September ash plumes from Bagana rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 35-65 km NW and W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

BARREN ISLAND Andaman Is 12.278°N, 93.858°E; summit elev. 354 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 13-14 September ash plumes from Barren Island rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted about 20-100 km W and
NE.

Geologic Summary. Barren Island, a possession of India in the Andaman
Sea about 135 km NE of Port Blair in the Andaman Islands, is the only
historically active volcano along the N-S-trending volcanic arc
extending between Sumatra and Burma (Myanmar). The 354-m-high island
is the emergent summit of volcano that rises from a depth of about
2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-
km-wide caldera with walls 250-350 m high. The caldera, which is open
to the sea on the W, was created during a major explosive eruption in
the late Pleistocene that produced pyroclastic-flow and -surge
deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course
of historical eruptions. Lava flows fill much of the caldera floor and
have reached the sea along the western coast during historical
eruptions.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Barren Island Information from the Global Volcanism Program

BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev.
748 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 9-11 and 14-15 September ash plumes from Batu Tara rose to an
altitude of 1.5 m (5,000 ft) a.s.l. and drifted 25-45 km W and NW.

Geologic Summary. 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.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Batu Tara Information from the Global Volcanism Program

CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views and analyses of satellite imagery, the
Buenos Aires VAAC reported that on 15 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 2.1 km
(7,000 ft) a.s.l. The plume drifted NE and SE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a
Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf
of Corcovado. A pyroclastic-surge and pumice deposit considered to
originate from the eruption that formed the elliptical 2.5 x 4 km wide
summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-
high obsidian lava dome occupies much of the caldera floor. 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 1122 m.

Map

Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)

Chaitén Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
on 12 and 14 September ash plumes from Dukono rose to an altitude of
2.4 km (8,000 ft) a.s.l. and drifted 25-75 km W and SW.

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. During a major
eruption in 1550, a lava flow filled in the strait between Halmahera
and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano
presenting a broad, low profile with multiple summit peaks and
overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit
crater complex, contains a 700 x 570 m crater that has also been
active during historical time.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m

On 10 and 14 September, INSIVUMEH reported that explosions from Fuego
produced ash plumes that rose to altitudes of 4.1-4.7 km
(13,500-15,400 ft) a.s.l. and drifted as far away as 10 km W, SW, and
S. Some explosions were accompanied by rumbling noises and shock
waves. Incandescent material was ejected 100 m high and avalanches
descended multiple ravines.

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.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Fuego Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 9-15 September, 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. Weak, sporadic explosions from the ocean entry were seen
on 10 September. Occasional thermal anomalies detected in satellite
images and visual observations revealed active surface lava flows.

The vent in Halema'uma'u crater continued to produce a diffuse white
plume that drifted mainly SW. The plume briefly turned brown on 9
September from a rockfall. Small amounts of ash were retrieved from
collection bins placed near the plume. Incandescence from small
openings in the floor of the vent, about 200 m below the Halema'uma'u
crater floor, was visible at night with varying intensity. During the
night from 12 to13 September, spattering from the opening was seen on
the web camera. The sulfur dioxide emission rate at the summit
remained elevated; 900 tonnes per day was measured on 11 September.
The 2003-2007 average rate was 140 tonnes per day.

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.

Map

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m

On 11 and 14 September, INSIVUMEH reported that white and blue plumes
from Pacaya's MacKenney cone rose 300 m and drifted NW, S, and SW.
Multiple lava flows 75-250 m long traveled W.

Geologic Summary. Eruptions from Pacaya, one of Guatemala's most
active volcanoes, are frequently visible from Guatemala City, the
nation's capital. Pacaya is a complex volcano constructed on the
southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A
cluster of dacitic lava domes occupies the caldera floor. The Pacaya
massif includes the Cerro Grande lava dome and a younger volcano to
the SW. Collapse of Pacaya volcano about 1,100 years ago produced a
debris-avalanche deposit that extends 25 km onto the Pacific coastal
plain and left an arcuate somma rim inside which the modern Pacaya
volcano (MacKenney cone) grew. During the past several decades,
activity at Pacaya has consisted of frequent Strombolian eruptions
with intermittent lava flow extrusion on the flanks of MacKenney cone,
punctuated by occasional larger explosive eruptions.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Pacaya Information from the Global Volcanism Program

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

CENAPRED reported that during 10-14 September emissions of steam and
gas from Popocatépetl contained slight amounts of ash.

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.

Map

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Popocatépetl Information from the Global Volcanism Program

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

RVO reported that during 4-10 September gray ash and white 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 large explosions occurred
during an eight-hour period one unspecified evening. Based on analyses
of satellite imagery, the Darwin VAAC reported that during 11-13 and
15 September ash plumes rose to an altitude of 2.4 km (8,000 ft)
a.s.l. and drifted 35-130 km N and NW.

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.

Map

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash
Advisory Centre (VAAC)

Rabaul Information from the Global Volcanism Program

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

Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima during 9-15 September produced plumes that rose to
altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted S, SE, and
E.

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.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m

On 14 September, INSIVUMEH reported that an explosion from Santa
María's Santiaguito lava dome complex produced an ash plume that rose
to an altitude of 3.3 km (10,800 ft) a.s.l. The plume drifted SW and
cause ashfall downwind. Avalanches descended the SW flank of the dome.

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.

Map

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia,
e Hidrologia (INSIVUMEH)

Santa María Information from the Global Volcanism Program

SLAMET Central Java (Indonesia) 7.242°S, 109.208°E; summit elev. 3428
m

The Darwin VAAC reported that on 12 September a low-level ash plume
from Slamet was observed by a pilot. Ash was not identified on
satellite imagery.

Geologic Summary. Slamet, Java's second highest volcano at 3428 m and
one of its most active, has a cluster of about three dozen cinder
cones on its lower SE-NE flanks and a single cinder cone on the
western flank. Slamet is composed of two overlapping edifices, an
older basaltic-andesite to andesitic volcano on the west and a younger
basaltic to basaltic-andesite one on the east. Gunung Malang II cinder
cone on the upper eastern flank on the younger edifice fed a lava flow
that extends 6 km to the east. Four craters occur at the summit of
Gunung Slamet, with activity migrating to the SW over time. Historical
eruptions, recorded since the 18th century, have originated from a 150-
m-deep, 450-m-wide, steep-walled crater at the western part of the
summit and have consisted of explosive eruptions generally lasting a
few days to a few weeks.

Map

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Slamet Information from the Global Volcanism Program

SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev.
799 m

Based on information from JMA, the Tokyo VAAC reported explosions from
Suwanose-jima during 13-14 September. Details of possible resulting
ash plumes 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 east 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 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.

Map

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Suwanose-jima Information from the Global Volcanism Program

Additional Reports of Volcanic Activity by Country

The following websites have frequently updated activity reports on
volcanoes in addition to those that meet the criteria for inclusion in
the Weekly Volcanic Activity Report. The websites are organized by
country and are maintained by various agencies.

Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
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