****************************************************************
GVP/USGS Weekly Volcanic Activity Report
6-12 June 2007
http://www.volcano.si.edu/reports/usgs/
****************************************************************
New Activity/Unrest: | Karymsky, Russia | Kliuchevskoi, Russia | Santa
María, Guatemala
Ongoing Activity: | Bagana, Papua New Guinea | Kilauea, USA | Langila,
Papua New Guinea | Masaya, Nicaragua | Sakura-jima, Japan | Semeru,
Indonesia | Shiveluch, Russia | Soufrière Hills, Montserrat | St.
Helens, USA | Tungurahua, Ecuador | Ubinas, Perú
New Activity/Unrest
KARYMSKY Kamchatka Peninsula, Russia 54.05°N, 159.43°E; summit elev. 1,536 m
Seismic activity at Karymsky was slightly above background levels during
1-8 June. According to visual observations, a gas-and-steam plume was
visible on 5 June. KVERT lowered the Level of Concern Color Code from
Orange to Yellow <http://www.avo.alaska.edu/color_codes.php>.
On 9 June, seismic data indicated that an explosion may have produced an
ash plume that rose to an altitude of 3.8 km (12,500 ft) a.s.l. Strong
seismicity and further possible explosions or avalanches followed the
event. Clouds obscured summit observations. The Level of Concern Color
Code was raised to Orange.
Based on information from KEMSD, the Tokyo VAAC reported that eruption
plumes rose to 3.7-7 km (12,000-23,000 ft) a.s.l. during 9-12 June. Ash
was not identified on satellite imagery.
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.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT)
http://www.kscnet.ru/ivs/kvert/updates.shtml,
Tokyo Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
Karymsky Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1000-13=
KLIUCHEVSKOI Kamchatka Peninsula, Russia 56.06°N, 160.64°E; summit elev.
4,835 m
KVERT reported that during 1-8 June, seismic activity at Kliuchevskoi
continued above background levels and a thermal anomaly in the crater
was detected on satellite imagery. Video and visual observations during
1-4 June indicated Strombolian and Vulcanian eruptions at the summit
crater. Lava flows generated phreatic bursts from places where hot lava
interacted with ice on the NW and SE flanks. Ash plumes rose to
altitudes of 7 km (23,000 ft) a.s.l. and drifted E and SE during 1-6
June. Plumes were seen on satellite imagery drifting E and S during 1-8
June. Based on information from KVERT, the Tokyo VAAC reported that an
ash plume rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted
NW on 12 June. The Level of Concern Color Code remained at Orange
<http://www.avo.alaska.edu/color_codes.php>.
Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions have occurred during the
past 3,000 years, mostly on the NE and SE flanks of the conical volcano
between 500 m and 3,600 m elevation. The morphology of its 700-m-wide
summit crater has been frequently modified by historical eruptions,
which have been recorded since the late-17th century. Historical
eruptions have originated primarily from the summit crater, but have
also included major explosive and effusive eruptions from flank craters.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT)
http://www.kscnet.ru/ivs/kvert/updates.shtml,
Tokyo Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html
Kliuchevskoi Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1000-26=
SANTA MARÍA Guatemala 14.756°N, 91.552°W; summit elev. 3,772 m
CONRED reported that the Observatory Vulcanológico de Santiaguito
(OVSAN) and several seismic stations registered a lahar from Santa María
on 5 June. The lahar descended the Nima I river and carried blocks 1-1.5
m in diameter and tree branches. The approximately 12-m-wide by
3-m-thick deposit was hot and smelled of sulfur. On 7 June, INSIVUMEH
reported that explosions from Caliente dome produced steam-and-ash
plumes that rose to altitudes of 4.3-4.7 km (14,000-15,400 ft) a.s.l.
and drifted SW. A plume rose from a cooling lava flow at the NE base of
the lava dome. Continuous landslides of blocks and ash were noted on the
SW flank.
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,
Coordinadora Nacional para la Reducción de Desastres (CONRED)
http://www.conred.org/principal.php
Santa María Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1402-03=
Ongoing Activity
BAGANA Bougainville Island, Papua New Guinea 6.14°S, 155.19°E; summit
elev. 1,750 m
RVO reported that white vapor emissions from Bagana's summit crater
continued during 1-11 June. Based on satellite imagery and information
from RVO, the Darwin VAAC reported that a low-level diffuse plume rose
to an altitude of 3 km (10,000 ft) a.s.l. and drifted W on 11 June.
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.
Sources: Herman Patia, Rabaul Volcano Observatory,
Darwin Volcanic Ash Advisory Centre (VAAC)
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=
KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m
During 6-12 June, lava from Kilauea flowed SE across a growing lava
delta into the ocean at the Poupou entry. Incandescence was visible from
several vents in the Pu'u 'O'o crater and on 10 June from breakouts
above the Pulama pali fault scarp and on 11 June at the base of the
pali. An earthquake swarm that began on 12 May continued beneath the S
flank and upper rift zones. Aerial observation and satellite imagery
confirmed that the 2-km-long Petunia flow, initiating about 1 km S of
Pu'u 'O'o crater, was somewhat active. Surface flow activity was seen
inland of the Poupou entry on the E side of the flow field.
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
RVO reported that the emission of ash plumes from Langila's Crater 2
continued during 1-10 June and were occasionally forceful. Ash plumes
rose to altitudes of 2.3-4.3 km (7,500-14,100 ft) a.s.l. and drifted
NNW. Ashfall was reported at Kilenge Catholic Mission (about 10 km NW of
the volcano) and surrounding areas. The emissions were continuous on 6,
7, and 10 June and accompanied by roaring noises. Booming noises were
heard on 1 and 10 June. Crater 3 was quiet.
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=
MASAYA Nicaragua 11.984°N, 86.161°W; summit elev. 635 m
The Washington VAAC reported a plume from Masaya composed of little to
no ash was visible on satellite imagery on 9 June drifting W.
Geologic Summary. Masaya is one of Nicaragua's most unusual and most
active volcanoes. It is a broad, 6 x 11 km basaltic caldera with
steep-sided walls up to 300 m high that is filled on its NW end by more
than a dozen vents erupted along a circular fracture system 4 km in
diameter. The twin volcanoes of Nindiri and Masaya, the source of
historical eruptions, were constructed at the southern end of the
fracture system and contain multiple summit craters. A major basaltic
plinian tephra was erupted from Masaya about 6,500 years ago. Historical
lava flows cover much of the caldera floor and have confined a lake to
the far eastern end of the caldera. A lava flow from the 1670 eruption
overtopped the N caldera rim. Masaya has been frequently active since
the time of the Spanish Conquistadors, when an active lava lake prompted
several attempts to extract the volcano's molten "gold."
Source: Washington Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/messages.html
Masaya Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=1404-10=
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 ash plumes
from Sakura-jima rose straight up to an altitude of 2.1 km (7,000 ft)
a.s.l. on 8, 10, and 11 June. The 10 June plume drifted S. Ash was not
detected on satellite imagery.
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
Sakura-jima Information from the Global Volcanism Program
http://www.volcano.si.edu/gvp/world/volcano.cfm?vnum=0802-08=
SEMERU Java, Indonesia 8.11°S, 112.92°E; summit elev. 3,676 m
The Darwin VAAC reported that a pilot observed an ash plume over the
summit of Semeru on 12 June. Ash was not detected on satellite imagery.
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.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.bom.gov.au/info/vaac/advisories.shtml
Semeru Information from the Global Volcanism Program
http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-30=
SHIVELUCH Kamchatka Peninsula, Russia 56.653°N, 161.360°E; summit elev.
3,283 m
KVERT reported that seismic activity at Shiveluch continued above
background levels during 1-8 June and a thermal anomaly in the crater
was detected on satellite imagery. Gas-and-steam plumes rose to
altitudes of 4.5 km (14,800 ft) a.s.l. during 1-3 and 5 June. Ash plumes
rose to altitudes of 4.5-6 km (14,800-19,700 ft) a.s.l. on 1 and 6 June
and were seen on satellite imagery drifting S and SE on 3 and 6 June.
Based on seismic interpretation, multiple ash plumes rose to 6.5 km
(21,300 ft) a.s.l. during 1-8. The Tokyo VAAC reported that eruption
plumes rose to altitudes of 4.3-9.1 km (14,000-30,000 ft) a.s.l. on 9,
11, and 12 June, based on information from KVERT and KEMSD. Ash was not
identified on satellite imagery. The Level of Concern Color Code
remained at Orange <http://www.avo.alaska.edu/color_codes.php>.
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 (KVERT)
http://www.kscnet.ru/ivs/kvert/updates.shtml,
Tokyo Volcanic Ash Advisory Center (VAAC)
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
MVO reported that during 1-12 June the lava dome at Soufrière Hills
changed very little based on visual observations from a helicopter and
seismic activity was very low. Low-level rockfall and pyroclastic flow
activity continued during 1-12 June. On 8 June, a small pyroclastic flow
was observed in the upper parts of Farrell's Plain to the N. Fresh
pyroclastic deposits were also observed to the E in the Tar River Valley
and on the S side of the lava dome. On 11 June, heavy rains generated
lahars in all drainages. Two pyroclastic flows occurred. The Washington
VAAC reported that on 11 June, an ash plume was visible on satellite
imagery drifting NW. The plume may have reached an altitude of 3.7 km
(12,000 ft) a.s.l. The Alert Level remained 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 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 (VAAC)
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 indicated that during 6-12
June lava-dome growth at Mount St. Helens continued. Seismicity
persisted at low levels, punctuated by M 1.5-2.5, and occasionally
larger, earthquakes. Clouds inhibited visual observations during 6-11
June. A weak gas-and-steam plume was visible rising from the lava dome
on 12 June.
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
During 5-9 June, IG reported that minor ash plumes from Tungurahua rose
to altitudes of no more than 5.5 km (18,000 ft) a.s.l. and drifted W.
Ashfall was reported from areas WSW and NW on 6 June and roaring noises
were reported during 5-6 and 9-10 June. Lahars transporting stones and
wood were observed on the W flank in the Bilbao drainage on 6 June.
Later that day, lahars were noted on the N flank in the Vazcún drainage.
On 7 June, several mudflows affected W and NW drainages and in the
Pampas sector, covered a highway with debris 1 m thick. On 8 June,
multiple lahars again traveled in W and NW drainages. Lahars carried
blocks 20-30 cm in diameter and interrupted traffic in the Pampas
sector. Mudflows were abundant in Pama on 9 June.
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 Significant Meteorological Information (SIGMET) advisories, the
Buenos Aires VAAC reported that on 12 June an ash plume from Ubinas rose
to an altitude of 6.7 km (22,000 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 (VAAC)
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**
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
<http://www.volcano.si.edu/reports/usgs/>++++++++++++++++++++++++++++++++++++++++++
==============================================================
To unsubscribe from the volcano list, send the message:
signoff volcano
to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx
To contribute to the volcano list, send your message to:
volcano@xxxxxxxx Please do not send attachments.
==============================================================
