Smithsonian/USGS Weekly Volcanic Activity Report 23-29 November 2011
From: "Kuhn, Sally" <KUHNS@si.edu>
*****************************************************************************************
Smithsonian/USGS Weekly Volcanic Activity Report
23-29 November 2011
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Galeras, Colombia | Tungurahua, Ecuador
Ongoing Activity: | Dukono, Halmahera | Hierro, Canary Islands (Spain) |
Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kizimen, Eastern
Kamchatka (Russia) | Popocat?petl, M?xico | Puyehue-Cord?n Caulle, Central Chile
| Sakura-jima, Kyushu | Santa Mar?a, Guatemala | Shiveluch, Central Kamchatka
(Russia)
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
GALERAS Colombia 1.22?N, 77.37?W; summit elev. 4276 m
INGEOMINAS reported that during 15-22 November steam from Galeras rose from the
main crater, two craters to the N and SW (Paisita and Chavas, respectively),
and a crack on the N flank of the active cone. Seismicity was at low levels,
although some earthquakes were characterized as "tornillo-type." During 23-24
November the seismic network detected an emerging seismic pattern of
"tornillo-type" earthquakes similar to patterns detected prior to past
eruptions. Gas emissions also decreased. INGEOMINAS raised the Alert Level to
II (Orange; "probable eruption in term of days or weeks") on 24 November.
Geologic Summary. Galeras, a stratovolcano with a large breached caldera located
immediately W of the city of Pasto, is one of Colombia's most frequently active
volcanoes. The dominantly andesitic Galeras volcanic complex has been active
for more than 1 million years, and two major caldera collapse eruptions took
place during the late Pleistocene. Longterm extensive hydrothermal alteration
has affected the volcano. This has contributed to large-scale edifice collapse
that has occurred on at least three occasions, producing debris avalanches that
swept to the W and left a large horseshoe-shaped caldera inside which the modern
cone has been constructed. Major explosive eruptions since the mid Holocene have
produced widespread tephra deposits and pyroclastic flows that swept all but the
southern flanks. A central cone slightly lower than the caldera rim has been the
site of numerous small-to-moderate historical eruptions since the time of the
Spanish conquistadors.
Source: Instituto Colombiano de Geolog?a y Miner?a (INGEOMINAS)
http://www.ingeominas.gov.co//
TUNGURAHUA Ecuador 1.467?S, 78.442?W; summit elev. 5023 m
IG reported that increased seismicity from Tungurahua was detected at 1540 on 27
November, and at 1650 the seismic network recorded four volcano-tectonic
earthquakes. Two small explosions at 1701 and 1705 were followed by a large
explosion at 1718. Pyroclastic flows descended the Achupashal, Chotanpamba, and
Mandur drainages on the NW and W flanks. Two more large explosions were detected
at 1731 and 1735. Incandescent blocks traveled 1 km down the flanks, and roaring
noises and sounds resembling "cannon shots" were reported. Ashfall was reported
in Manzano (8 km SW), Bilbao (8 km W), and Pillate (8 km W), ash and tephra
fell in Cotal? (8 km NW), and tephra fell in Cus?a (8 km NW). At 1905 a
pyroclastic flow descended the S and SW flanks.
At 0200 on 28 November an explosion ejected incandescent material that fell on
all flanks, and generated a pyroclastic flow that descended the Achupashal
drainage. Starting before 0500 until 0900 an almost constant roar was heard and
incandescent blocks traveled 1 km down the flanks, especially towards the W and
NW. Three pyroclastic flows were noted on the S flank. Windows vibrated at the
Tungurahua Observatory (OVT) in Guadalupe (14 km N). During the day, an ash
plume rose 3 km above the crater and drifted in multiple directions. White
ashfall was reported in Manzano, Choglont?s (SW), Pondoa (8 km N), and Runt?n
(6 km NNE). In the evening incandescent blocks that were ejected 300 m above
the crater rolled 400-500 m down the flanks. On 29 November an explosion
detected at 0611 produced a small pyroclastic flow that traveled 500 m. Another
pyroclastic flow at 0955 traveled 1 km W. Gas-and-ash plumes rose 4 km above the
crater and drifted SE and W. According to a news article, people in high risk
areas on the flanks, in communities such as Cus?a, Juive, Palictahua, and
Manzano, evacuated voluntarily.
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 Ba?os on
the N side of the volcano.
Sources: Instituto Geof?sico-Escuela Polit?cnica Nacional (IG)
http://www.igepn.edu.ec/,
Agence France-Presse
http://news.yahoo.com/ecuador-volcano-spews-fiery-rocks-warnings-issued-173227901.html
Ongoing Activity
DUKONO Halmahera 1.68?N, 127.88?E; summit elev. 1335 m
Based on analyses of satellite imagery, the Darwin VAAC reported that during
27-28 November ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft)
a.s.l. and drifted 65-110 km NW.
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.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
HIERRO Canary Islands (Spain) 27.73?N, 18.03?W; summit elev. 1500 m
Instituto Geogr?fico Nacional (IGN) reported that during 23-29 November the
submarine eruption continued S of El Hierro Island. During this period, the
mean amplitude of the tremor showed a slight increase. On 26 November large
steaming fragments of lava appeared intermittently floating over the emission
center. On 27 November, the emissions were more intense and a few hundred
fragments could be observed floating simultaneously, with mean dimensions
between 0.5 and 2 m. Some samples of the fragments were collected from a ship
near the emission area.
During the period, 121 seismic events were located, most of them offshore to the
N of the island at depths of 15-23 km and a maximum magnitude of 3.3. Seven of
these events were felt by residents at a maximum intensity value of III using
EMS-98 (European Macroseismic Scale). GPS data analyses trended towards
stability in the horizontal components, while in the vertical component most of
the stations showed subsidence while stations in the NE of the island also
trended towards stability.
Geologic Summary. The triangular island of Hierro is the SW-most and least
studied of the Canary Islands. The massive Hierro shield volcano is truncated
by a large NW-facing escarpment formed as a result of gravitational collapse of
El Golfo volcano about 130,000 years ago. The steep-sided 1500-m-high scarp
towers above a low lava platform bordering 12-km-wide El Golfo Bay, and three
other large submarine landslide deposits occur to the SW and SE. Three
prominent rifts oriented NW, NE, and south at 120 degree angles form prominent
topographic ridges. The subaerial portion of the volcano consists of flat-lying
Quaternary basaltic and trachybasaltic lava flows and tuffs capped by numerous
young cinder cones and lava flows. Holocene cones and flows are found both on
the outer flanks and in the El Golfo depression. Hierro contains the greatest
concentration of young vents in the Canary Islands. Uncertainty surrounds the
report of an historical eruption in 1793.
Source: Instituto Geogr?fico Nacional (IGN)
http://www.01.ign.es/ign/layout/volcaVolcanologia.do
KARYMSKY Eastern Kamchatka (Russia) 54.05?N, 159.45?E; summit elev. 1536 m
KVERT reported that seismic activity continued at a moderate level at Karymsky
during 18-25 November and indicated that possible ash plumes rose to an
altitude of 2.8 km (9,200 ft) a.s.l. during 19-22 November. Satellite imagery
showed a thermal anomaly on the volcano during 18, 20, and 24 November. The
Aviation Color Code remained at Orange.
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 (KVERT)
http://www.kscnet.ru/ivs/kvert/index_eng.php
KILAUEA Hawaii (USA) 19.421?N, 155.287?W; summit elev. 1222 m
During 23-29 November, HVO reported that the lava lake circulated and
periodically rose and fell in the deep pit within Kilauea's Halema'uma'u
Crater, remaining below the inner ledge (75 m below the crater floor). Almost
daily measurements indicated that the gas plume from the vent continued to
deposit variable amounts of ash and fresh spatter nearby. Incandescence was
visible from the E and W edges of the Pu'u 'O'o crater floor, and from the 21
September fissure on the SE flank of Pu'u 'O'o cone. Pahoehoe flows, fed
through lava tubes from the fissure, continued to be active about 5.7 km SE of
Pu'u 'O'o based on intermittent views from satellite. Incandescence from a
skylight on the lava tube was also observed. Short lava flows issued from the E
edge of the crater floor on 23 November and from both the E and W edges of the
crater floor on 27 November.
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 (HVO)
http://hvo.wr.usgs.gov/
KIZIMEN Eastern Kamchatka (Russia) 55.130?N, 160.32?E; summit elev. 2376 m
KVERT reported moderate seismic activity at Kizimen during 18-25 November and a
thermal anomaly that was detected daily in satellite images. A large lava flow
on the NE and E flanks continued to effuse, and the crater was occasionally
incandescent at night. Video observations showed gas-and-steam activity during
20 and 22-24 November. The Aviation Color Code remained at Orange.
Geologic Summary. Kizimen is an isolated, conical stratovolcano that is
morphologically similar to Mount St. Helens prior to its 1980 eruption. The
summit of Kizimen consists of overlapping lava domes, and blocky lava flows
descend the flanks of the volcano, which is the westernmost of a volcanic chain
north of Kronotsky volcano. The 2,376-m-high Kizimen was formed during four
eruptive cycles beginning about 12,000 years ago and lasting 2,000-3,500 years.
The largest eruptions took place about 10,000 and 8300-8400 years ago, and three
periods of longterm lava-dome growth have occurred. The latest eruptive cycle
began about 3,000 years ago with a large explosion and was followed by
lava-dome growth lasting intermittently about 1,000 years. An explosive
eruption about 1,100 years ago produced a lateral blast and created a 1.0 x 0.7
km wide crater breached to the NE, inside which a small lava dome (the fourth at
Kizimen) has grown. A single explosive eruption, during 1927-28, has been
recorded in historical time.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
http://www.kscnet.ru/ivs/kvert/index_eng.php
POPOCATEPETL M?xico 19.023?N, 98.622?W; summit elev. 5426 m
CENAPRED reported that during 22-28 November steam-and-gas emissions rose from
Popocat?petl and crater incandescence was observed during most nights and early
mornings. Steam-and-gas emissions occasionally contained small amounts of ash on
29 November.
Geologic Summary. Popocat?petl, 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.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
http://www.cenapred.unam.mx/es/
PUYEHUE-CORDON CAULLE Central Chile 40.590?S, 72.117?W; summit elev. 2236 m
Based on seismicity during 23-28 November, OVDAS-SERNAGEOMIN reported that the
eruption from the Cord?n Caulle rift zone, part of the Puyehue-Cord?n Caulle
volcanic complex, continued at a low level. Cloud cover prevented web camera
views during 24-25 November, but satellite imagery showed a discontinuous ash
plume drifting E and reaching the Atlantic Ocean on 24 November, and a
fan-shaped ash plume spreading NE to SE on 25 November. Plumes observed with
the web camera during 26-27 November rose 2.3-2.5 km above the crater.
According to a news article, flights out of Uruguay were disrupted or cancelled
on 26 November due to ash plumes. A plume observed in satellite imagery drifted
300 km E on 28 November. The Alert Level remained at Red.
Geologic Summary. The Puyehue-Cord?n Caulle volcanic complex (PCCVC) is a large
NW-SE-trending late-Pleistocene to Holocene basaltic-to-rhyolitic transverse
volcanic chain SE of Lago Ranco. The 1799-m-high Pleistocene Cordillera Nevada
caldera lies at the NW end, separated from Puyehue stratovolcano at the SE end
by the Cord?n Caulle fissure complex. The Pleistocene Mencheca volcano with
Holocene flank cones lies NE of Puyehue. The basaltic-to-rhyolitic Puyehue
volcano is the most geochemically diverse of the PCCVC. The flat-topped,
2236-m-high Puyehue volcano was constructed above a 5-km-wide caldera and is
capped by a 2.4-km-wide summit caldera of Holocene age. Lava flows and domes of
mostly rhyolitic composition are found on the eastern flank of Puyehue.
Historical eruptions originally attributed to Puyehue, including major
eruptions in 1921-22 and 1960, are now known to be from the Cord?n Caulle rift
zone. The Cord?n Caulle geothermal area, occupying a 6 x 13 km wide
volcano-tectonic depression, is the largest active geothermal area of the
southern Andes volcanic zone.
Sources: Servicio Nacional de Geolog?a y Miner?a (SERNAGEOMIN)
http://www.sernageomin.cl/,
Agence France-Presse
http://www.news24.com/World/News/Chile-volcano-ash-disrupts-flights-20111126
SAKURA-JIMA Kyushu 31.585?N, 130.657?E; summit elev. 1117 m
Based on information from JMA, the Tokyo VAAC reported that during 23 and 25-29
November explosions from Sakura-jima produced plumes that rose to altitudes of
1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted W, S, E, and NE.
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
SANTA MARIA Guatemala 14.756?N, 91.552?W; summit elev. 3772 m
INSIVUMEH reported that during 24-25 November block avalanches originated from
the crater at Santa Mar?a's Santiaguito lava-dome complex as well as from lava
flows. Ash plumes rose 500 m above the crater and drifted SW. During 28-29
November explosions generated shock waves and rumbling noises, as well as ash
plumes that rose 700 m above the crater and drifted W. Incandescence was
observed at night from Caliente dome and avalanches from lava flows descended
the S and NE flanks.
Geologic Summary. Symmetrical, forest-covered Santa Mar?a 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.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e
Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/
SHIVELUCH Central Kamchatka (Russia) 56.653?N, 161.360?E; summit elev. 3283 m
KVERT reported that moderate seismic activity was detected at Shiveluch during
18-25 November, and satellite imagery showed a daily thermal anomaly over the
lava dome. Ground-based observers noted that a viscous lava flow continued to
effuse in the crater formed during a 2010 eruption. An ash plume detected in
satellite imagery drifted 21 km W on 18 November. Strong fumarolic activity at
the lava dome was observed on 18, 21, and 24 November; clouds prevented
observations on the other days of the week. The Aviation Color Code remained at
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.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
http://www.kscnet.ru/ivs/kvert/index_eng.php
+++++++++++++++++++++++++++++++++++++
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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