*******************************************************
GVP/USGS Weekly Volcanic Activity Report
22-28 November 2006
http://www.volcano.si.edu/reports/usgs/index.cfm
*******************************************************
New Activity/Unrest: | Nyamuragira, D.R. of Congo | Taal, Philippines
Ongoing Activity: | Bagana, Papua New Guinea | Barren Island, India |
Etna, Italy | Karangetang, Indonesia | Karymsky, Russia | Kilauea, USA |
Langila, Papua New Guinea | Rabaul, Papua New Guinea | Sakura-jima,
Japan | Sangay, Ecuador | Semeru, Indonesia | Soufrière Hills,
Montserrat | St. Helens, USA | Tungurahua, Ecuador | Ubinas, Perú |
Ulawun, Papua New Guinea
New Activity/Unrest
NYAMURAGIRA Democratic Republic of the Congo 1.408°S, 29.20°E; summit
elev. 3,058 m; All times are local (= UTC + 2 hours)
GVO reported that on 27 November at 2200, incandescence from a new
eruption of Nyamuragira was visible from Goma, about 30 km S. The
intense red glow suggested lava fountaining and flows. Sustained
long-period earthquake activity had been present since 26 October.
Geologic Summary. 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 3,058-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.
Source: Jacques Durieux, Goma Volcano Observatory
Nyamuragira Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0203-02=
TAAL Luzon. Philippines 14.002°N, 120.993°E; summit elev. 1,977
According to news articles, geysers of muddy water 3-5 m high occurred
in the NNE portion of Taal’s main crater during 17-21 November. On 24
November, a new episode of 50-cm-high geyser activity and increased
seismicity prompted PHIVOLCS to raise the Alert Level from 1 to 2.
Geologic Summary. Taal volcano is one of the most active volcanoes in
the Philippines and has produced some of its most powerful historical
eruptions. In contrast to Mayon volcano, Taal is not topographically
prominent, but its prehistorical eruptions have greatly changed the
topography of SW Luzon. The 15 x 20 km Taal caldera is largely filled by
Lake Taal, whose 267 sq km surface lies 700 m below the S caldera rim
and only 3 m above sea level. The maximum depth of the lake is 160 m,
and several eruptive centers lie submerged beneath the lake. The
5-km-wide Volcano Island in north-central Lake Taal is the location of
all historical eruptions. The island is a complex volcano composed of
coalescing small stratovolcanoes, tuff rings, and scoria cones that has
grown about 25% in area during historical time. Powerful pyroclastic
flows and surges from historical eruptions of Taal have caused many
fatalities.
Sources: Xinhua
http://english.people.com.cn/200611/21/eng20061121_323739.html,
Associated Press
http://globalnation.inquirer.net/news/news/view_article.php?article_id=34536
Taal Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0703-07=
Ongoing Activity
BAGANA Bougainville Island, Papua New Guinea 6.14°S, 155.19°E; summit
elev. 1,750 m
A diffuse plume from Bagana was visible on satellite imagery on 22
November. The height and direction of the plume were not reported.
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.
Source: Darwin Volcanic Ash Advisory Centre
http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
Bagana Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0505-02=
BARREN ISLAND Andaman Islands, Indian Ocean, India 12.29°N, 93.88°E;
summit elev. 354 m
The Darwin VAAC reported that a diffuse plume from Barren Island was
visible on satellite imagery on 27 November. The height and direction of
the plume were not reported.
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 a 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 eruptions in the 19th century and
more recently in 1991 and 1995.
Source: Darwin Volcanic Ash Advisory Centre
http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
Barren Island Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0600-01=
ETNA Sicily, Italy 37.73°N, 15.00°E; summit elev. 3,315 m; All times are
local (= UTC + 1 hour [or 2 hours late March-late October])
INGV reported that a black ash plume from Etna rose above cloud cover to
an altitude of 4.8 km (15,700 ft) a.s.l. on 21 November at about 1500.
Light ashfall was reported from areas E and NE, including Rifugio
Citelli (6 km NE of the SE Crater). After 1900, the cloud cover
dissipated and the SE Crater came into view. Strombolian activity
generated jets of material greater than 300 m high. Lava flowed down the
SSE flanks and continued into 23 November. According to the Toulouse
VAAC, mild eruption plumes were visible on an INGV webcam on 24
November. Due to the possible presence of ash plumes, the Fontanarossa
airport in E Sicily closed from the evening of 24 November until early
28 November.
Geologic Summary. Mount Etna, towering above Catania, Sicily's second
largest city, has one of the world's longest documented records of
historical volcanism, dating back to 1500 BC. Historical lava flows
cover much of the surface of this massive basaltic stratovolcano, the
highest and most voluminous in Italy. Two styles of eruptive activity
typically occur at Etna. Persistent explosive eruptions, sometimes with
minor lava emissions, take place from one or more of the three prominent
summit craters, the Central Crater, NE Crater, and SE Crater. Flank
eruptions, typically with higher effusion rates, occur less frequently
and originate from fissures that open progressively downward from near
the summit. A period of more intense intermittent explosive eruptions
from Etna's summit craters began in 1995. The active volcano is
monitored by the Instituto Nazionale di Geofisica e Volcanologia (INGV)
in Catania.
Sources: Sonia Calvari and Boris Behncke, Istituto Nazionale di
Geofisica e Vulcanologia Sezione di Catania http://www.ct.ingv.it/ ,
Toulouse Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/OTH/FR/messages.html,
Agenzia Giornalistica Italia
http://www.agi.it/english/news.pl?doc=200611281240-1090-RT1-CRO-0-NF11&page=0&id=agionline-eng.oggitalia
Etna Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0101-06=
KARANGETANG [Api Siau] Siau Island, Indonesia 2.47°N, 125.29°E; summit
elev. 1,784 m
According to the Darwin VAAC, an eruption at Karangetang on 24 November
produced a small ash plume observed on satellite imagery that reached an
altitude of 3 km (10,000 ft) a.s.l.
Geologic Summary. Karangetang (also known as Api Siau) lies at the
northern end of the island of Siau, N of Sulawesi. The 1,784-m-high
stratovolcano contains five summit craters along a N-S line. One of
Indonesia's most active volcanoes, Karangetang has had more than 40
recorded eruptions since 1675. Twentieth-century eruptions have included
frequent explosions, sometimes accompanied by pyroclastic flows and lahars.
Source: Darwin Volcanic Ash Advisory Centre
http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
Karangetang Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0607-02=
KARYMSKY Kamchatka Peninsula, Russia 54.05°N, 159.43°E; summit elev. 1,536 m
Seismic data from Karymsky was available during 18-19 November.
Seismicity was elevated above background levels and the number of
shallow earthquakes was more than 90 per day. Explosions produced ash
plumes that possibly reached altitudes of 2.5 km (8,200 ft) a.s.l. based
on seismic data. A thermal anomaly in the crater was detected on 18-19
and 21-23 November. 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 22-28 November, lava from Kilauea continued to flow off of a lava
delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries.
During 23 and 25-26 November, incandescence was visible on the Paluma
pali and the coastal flats in the vicinity of the Campout flow.
Incandescence was intermittently visible from the East Pond and January
vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater.
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 21-26 November, eruptive activity at Langila's Crater 2 consisted
of continuous emissions of gray ash plumes that rose to altitudes of
2.3-3.3 km (7,600-10,800 ft) a.s.l. and drifted predominantly W and NW.
Fine ashfall was reported from areas downwind. Occasional roaring noises
were heard accompanying emissions.
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 20-23 November Rabaul emitted thick white vapor
accompanied by minor gray ash clouds. On 21 November, emissions created
a haze around the summit. On 22 and 23 November, plumes rose to about
1.7 km (5,600 ft) a.s.l. and drifted W and E, respectively. Fine ashfall
was reported from areas downwind to the W.
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: Herman Patia, Rabaul Volcano Observatory
Rabaul Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0502-14=
SAKURA-JIMA Kyushu, Japan 31.58°N, 130.67°E; summit elev. 1,117 m
Based on information from JMA, the Tokyo VAAC reported that explosions
from Sakura-jima on 22 November produced eruption plumes that reached an
altitude of 2.1 km (7,000 ft) a.s.l. and drifted W. On 26 November,
plumes reached an unreported altitude.
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
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
Sakura-jima Information from the Global Volcanism Program
http://www.volcano.si.edu/gvp/world/volcano.cfm?vnum=0802-08=
SANGAY Ecuador 2.03°S, 78.34°W; summit elev. 5,188 m
According to the Washington VAAC, an eruption from Sangay on 22 November
produced an ash plume observed on satellite imagery that drifted WNW.
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=
SEMERU Java, Indonesia 8.11°S, 112.92°E; summit elev. 3,676 m
Based on a pilot report, the Darwin VAAC reported that on 22 November an
ash plume from Semeru reached 7.6 km (25,000 ft) a.s.l. and drifted S.
On 24 November, CVGHM reported an eruption plume to an altitude of 4.4
km (14,000 ft) a.s.l. Incandescent material fell to the ground in all
directions within a 200 m radius from the center of the plume.
Geologic Summary. Semeru is the highest volcano on Java and one of its
most active. The symmetrical stratovolcano rises abruptly to 3,676 m
above coastal plains to the S and lies at the southern end of a volcanic
massif extending N to the Tengger caldera. Semeru has been in almost
continuous eruption since 1967. Frequent small-to-moderate Vulcanian
eruptions have accompanied intermittent lava dome extrusion, and
periodic pyroclastic flows and lahars have damaged villages below the
volcano. A major secondary lahar on 14 May 1981 caused more than 250
deaths and damaged 16 villages.
Sources: Darwin Volcanic Ash Advisory Centre
http://www.bom.gov.au/info/vaac/advisories.shtml,
Center of Volcanology and Geological Hazard Mitigation (CVGHM)
http://www.vsi.esdm.go.id/portal/html/index.php
Semeru Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-30=
SOUFRIÈRE HILLS Montserrat, West Indies 16.72°N, 62.18°W; summit elev.
1,052 m
During 17-24 November, lava-dome growth at Soufrière Hills continued and
was concentrated on the NE part of the edifice. Ash venting originated
from the westernmost of two cracks in the curved back of the shear
E-facing lobe on the summit. Rockfalls and small pyroclastic flows
traveled down the SW and NE flanks. Pyroclastic flows reached both the
upper region of Tuitts Ghaut (N) and the sea via the Tar River Valley
(E) on 23 November. An explosion produced an ash plume that rose to
altitudes of 1.5-1.7 km (4,900-5,600 ft) a.s.l.
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.
Source: Montserrat Volcano Observatory http://www.mvo.ms/
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 22-28
November 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. Inclement weather prohibited visual observations during
most of the reporting period.
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-
TUNGURAHUA Ecuador 1.47°S, 78.44°W; summit elev. 5,023 m
IG reported that during 21-28 November, emissions from Tungurahua
produced ash and steam plumes that reached altitudes of 6-9 km
(19,700-29,500 ft) a.s.l. and drifted predominantly NW and W. Ashfall
about 1 mm thick was reported from areas 8 km WSW on 21 November and
from areas 8 km W on 25 November. During 26-27 November, Strombolian
activity propelled incandescent material up to 600 m above the summit.
Blocks rolled 2 km down the flanks. Lightning was visible in an ash
plume that reached 7 km (23,000 ft) a.s.l. and ashfall was reported from
areas 8 km WSW. On 27 November, an ash plume rose to 9 km (29,500 ft)
a.s.l. and drifted W.
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 25 November. Ash plumes rose to 5.5 km (18,000
ft) a.s.l.
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
ULAWUN New Britain Island, Papua New Guinea 5.04°S, 151.34°E; summit
elev. 2,334 m
Based on satellite imagery, the Darwin VAAC reported a diffuse plume
from Ulawun on 22 November and an ash-and-steam plume on 28 November.
Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of this
valley. Historical eruptions date back to the beginning of the 18th
century. Twentieth-century eruptions were mildly explosive until 1967,
but after 1970 several larger eruptions produced lava flows and basaltic
pyroclastic flows, greatly modifying the summit crater.
Source: Darwin Volcanic Ash Advisory Centre
http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
Ulawun Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0502-12=
**+++++++++++++++++++++++++++++++++++++**
*Sally Kuhn Sennert*
*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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