VOLCANO: Smithsonian/USGS Weekly Volcanic Activity Report 22-28 February 2012

[Jean-François Smekens <jsmekens@xxxxxxx>]

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Smithsonian/USGS Weekly Volcanic Activity Report 22-28 February 2012
From: "Faulk, Elisabeth" <FaulkE@xxxxxx>
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Smithsonian/USGS Weekly Volcanic Activity Report


22-28 February 2012


Elisabeth Faulk - Weekly Report Editor

faulke@xxxxxx


URL: http://www.volcano.si.edu/reports/usgs/





New Activity/Unrest: | Cleveland, Chuginadak Island | Kanaga, Andreanof 
Islands | Rincón de la Vieja, Costa Rica | Tungurahua, Ecuador


Ongoing Activity: | Bezymianny, Central Kamchatka (Russia) | Hierro, 
Canary Islands (Spain) | Karymsky, Eastern Kamchatka (Russia) | Kilauea,
 Hawaii (USA) | Kizimen, Eastern Kamchatka (Russia) | Popocatépetl, 
México | Puyehue-Cordón Caulle, Central Chile | Sakura-jima, Kyushu | 
Santa María, Guatemala | Shiveluch, Central Kamchatka (Russia)



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




CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m


AVO reported that satellite observations of Cleveland during 22-28 
February revealed that the growth of the lava dome continued at a slow 
rate. Cloud cover over the volcano prevented views of the lava dome 
during 22 and 25-28 February. On 23 February a thermal anomaly was 
detected in partly cloudy satellite images. The Volcano Alert Level 
remained at Watch and the Aviation Color Code remained at Orange. No 
current seismic information was available because Cleveland does not 
have a real-time seismic network.


Geologic Summary. Symmetrical Mount Cleveland stratovolcano is situated 
at the western end of the uninhabited dumbbell-shaped Chuginadak Island 
in the east-central Aleutians. The 1,730-m-high stratovolcano is the 
highest of the Islands of Four Mountains group and is one of the most 
active in the Aleutians. Numerous large lava flows descend its flanks. 
It is possible that some 18th to 19th century eruptions attributed to 
Carlisle (a volcano located across the Carlisle Pass Strait to the NW) 
should be ascribed to Cleveland. In 1944 Cleveland produced the only 
known fatality from an Aleutian eruption. Recent eruptions from Mt. 
Cleveland have been characterized by short-lived explosive ash 
emissions, at times accompanied by lava fountaining and lava flows down 
the flanks.


Source: Alaska Volcano Observatory (AVO) https://www.avo.alaska.edu





KANAGA Andreanof Islands 51.923°N, 177.168°W; summit elev. 1307 m


AVO reported that no unusual activity was detected in seismic data or in
 partly-cloudy satellite images of Kanaga during 22-24 and 26-28 
February. Low-level volcanic tremor was detected on 25 February. The 
Volcano Alert Level remained at Advisory and the Aviation Color Code 
remained at Yellow.


Geologic Summary. Symmetrical Kanaga stratovolcano is situated within 
the Kanaton caldera at the northern tip of Kanaga Island. The rim of 
Kanaton caldera forms a 760-m-high arcuate ridge south and east of 
Kanaga; a lake occupies part of the SE caldera floor. The volume of 
subaerial dacitic tuff is smaller than would typically be associated 
with caldera collapse, and deposits of a massive submarine debris 
avalanche associated with edifice collapse extend nearly 30 km to the 
NNW. Several fresh lava flows from historical or late prehistorical time
 descend the flanks of Kanaga, in some cases to the sea. Historical 
eruptions, most of which are poorly documented, have been recorded since
 1763. Kanaga is also noted petrologically for ultramafic inclusions 
within an outcrop of alkaline basalt SW of the volcano. Fumarolic 
activity occurs in a circular, 200-m-wide, 60-m-deep summit crater and 
produces vapor plumes sometimes seen on clear days from Adak, 50 km to 
the east.


Source: Alaska Volcano Observatory (AVO) https://www.avo.alaska.edu





RINCON DE LA VIEJA Costa Rica 10.830°N, 85.324°W; summit elev. 1916 m


OVSICORI-UNA reported that seismic data revealed two eruptions on 19 and
 20 February from Rincón de la Vieja's active crater. Two more eruptions
 also occurred on 23 February. Explosions were heard in Guachipelin (11 
km SW) between 0400 and 0430.


Geologic Summary. Rincón de la Vieja, the largest volcano in NW Costa 
Rica, is a remote volcanic complex in the Guanacaste Range. The volcano 
consists of an elongated, arcuate NW-SE-trending ridge that was 
constructed within the 15-km-wide early Pleistocene Guachipelín caldera,
 whose rim is exposed on the south side. Rincón de la Vieja, sometimes 
known as the "Colossus of Guanacaste," has an estimated volume of 130 cu
 km and contains at least 9 major eruptive centers. Activity has 
migrated to the SE, where the youngest-looking craters are located. The 
twin cone of 1916-m-high Santa María volcano, the highest peak of the 
Rincón complex, is located at the eastern end of a smaller, 5-km-wide 
caldera and has a 500-m-wide crater. A plinian eruption producing the 
0.25 cu km Río Blanca tephra about 3500 years ago was the last major 
magmatic eruption from the volcano. All subsequent eruptions, including 
numerous historical eruptions possibly dating back to the 16th century, 
have been
  from the prominent crater containing a 500-m-wide acid lake (known as the Active Crater) located ENE of Von Seebach crater.


Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/





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


IG reported moderate activity at Tungurahua during 22-28 February. Steam
 plumes with some ash content rose to altitudes of 1-2 km (3,300-6,500 
ft) a.s.l. and drifted W during 22-24 February. Ash fall was reported in
 Palitahua (6 km SSW), Choglontus (13 km WSW), and Manzano (8 km SW) on 
23 February, and in the Mapayacu (SW) and Achupashal (NW) gorges on 24 
February. Strombolian activity was observed on 24 February, and 
incandescence material that rose as high as 500 m above the crater fell 
on the W and NW flanks. Ashfall was reported to the SW in Manzano again 
on 25 February. A steam-and-ash plume rose as high as 800 m above the 
crater and drifted W on 26 February. Crater incandescence was observed 
on 23 and 27 February.


Geologic Summary. The steep-sided Tungurahua stratovolcano towers more 
than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's
 capital city, and is one of Ecuador's most active volcanoes. Historical
 eruptions have all originated from the summit crater. They have been 
accompanied by strong explosions and sometimes by pyroclastic flows and 
lava flows that reached populated areas at the volcano's base. The last 
major eruption took place from 1916 to 1918, although minor activity 
continued until 1925. The latest eruption began in October 1999 and 
prompted temporary evacuation of the town of Baños on the N side of the 
volcano.


Source: Instituto Geofísico-Escuela Politécnica Nacional (IG) http://www.igepn.edu.ec/





Ongoing Activity





BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit elev. 2882 m


KVERT reported high levels of seismic activity at Bezymianny during 
17-24 February and a thermal anomaly that was detected daily in 
satellite images. Two short volcanic tremor episodes were reported on 15
 and 22 February. Gas-and-steam plumes, observed in satellite images, 
drifted NE on 20 and 22 February. The Aviation Color Code remained at 
Orange.


Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny 
volcano had been considered extinct. Three periods of intensified 
activity have occurred during the past 3,000 years. The latest period, 
which was preceded by a 1,000-year quiescence, began with the dramatic 
1955-56 eruption. That eruption, similar to the 1980 event at Mount St. 
Helens, produced a large horseshoe-shaped crater that was formed by 
collapse of the summit and an associated lateral blast. Subsequent 
episodic but ongoing lava-dome growth, accompanied by intermittent 
explosive activity and pyroclastic flows, has largely filled the 1956 
crater.


Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/updates.php





HIERRO Canary Islands (Spain) 27.73°N, 18.03°W; summit elev. 1500 m


Instituto Geográfico Nacional (IGN) reported that during 22-28 February 
the seismic amplitude recorded at every IGN station on El Hierro Island 
remained at very low values. Weak and intermittent discoloration was 
observed on the sea surface over the emission area. Only once were 
emitted lava fragments observed during the reported period.


One-hundred and seven seismic events were located, most of them in the 
central part of the island, with a few extending offshore to the S. 
Depths of the hypocenters varied between 8 and 20 km and magnitudes 
between 0.1 and 2.6 (46 events with magnitude 1 or greater). Three 
events were felt by residents with a maximum intensity value of III 
(EMS-98). GPS deformation analyses showed a slight trend to N in the 
stations located at the N of the island.


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 Geográfico Nacional (IGN) http://www.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 17-24 February, and indicated that possible ash plumes 
rose to an altitude of 3.5 km (11,500 ft) a.s.l. Satellite imagery 
showed a thermal anomaly at the volcano during 16-21 February and an ash
 plume that drifted 15 km E on 21 February. 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/updates.php





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


During 22-28 February, HVO reported that the lava lake circulated and 
periodically rose and fell in the deep pit within Kilauea's Halema'uma'u
 Crater. Web camera views and satellite images indicated that lava flows
 remained active within the abandoned Royal Gardens subdivision more 
than 7.5 km SE of Pu'u 'O'o. Lava flows also remained active high on the
 pali and across the December 2011 flows. Incandescence was visible on 
the NE and SE edges of the Pu'u 'O'o crater floor and on the upper part 
of the lava-tube system on Pu'u 'O'o's E flank during 23 and 26-28 
February. On 22 February a small lava flow from the SE source was 
observed by the web camera. Two minor lava flows issued from the NE 
source on 26 February, and one lava flow issued from NE source on 27 
February.


On 25 February HVO geologists aboard an overflight reported that the 
small cone on the NE source periodically ejected spatter, and the SE 
source fumed and produced a lava flow. They also noted that the flow 
advanced as two lobes; one lobe traveled along the E margin of the 
December 2011 flows and another advanced along the W margin of the 
December 2011 flows. During 27-28 February the web camera and satellite 
images indicated that both the E and W lobes continued moving down the 
pali.


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


During 17-24 February, KVERT reported moderate seismicity at Kizimen, 
strong gas-and-steam activity, and a large thermal anomaly that was 
detected daily in satellite images. Video and satellite observations 
indicated both continued effusion of a large lava flow on the E flank 
and accompanying hot avalanches. A large avalanche on the E flank, W of 
the lava flow, was observed on 21 February, and an ash plume rose to an 
altitude of 1 km (3,280 ft) a.s.l. On 22 February about 20 avalanches 
were reported. 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, ha
 s been recorded in historical time.


Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/updates.php





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


CENAPRED reported that during 22-28 February steam-and-gas emissions 
rose from Popocatépetl and crater incandescence was observed at night. 
Ash plumes rose 500-900 m above the crater during 22-24 February.


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.


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





PUYEHUE-CORDON CAULLE Central Chile 40.590°S, 72.117°W; summit elev. 2236 m


Based on seismicity detected during 21-27 February, OVDAS-SERNAGEOMIN 
reported that the eruption from the Cordón Caulle rift zone, part of the
 Puyehue-Cordón Caulle volcanic complex, continued at a low level. 
SERNAGEOMIN and ONEMI scientists aboard an overflight on 21 February 
reported that lava reached the valley of the Nilahue River, and two lava
 flows advanced to the N margin of the W crater. Some areas were covered
 in pumice and gray ash deposits. During 23-24 February plumes observed 
with a web camera rose 1 km above the crater; clouds prevented views on 
22 and 25-26 February. Satellite images showed ash plumes drifting 
60-100 km N and E during 22-23 February. Clouds prevented clear 
satellite views during 24-26 February. Crater incandescence was observed
 on 26 February. The Alert Level remained at Red.


Geologic Summary. The Puyehue-Cordón 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 Cordón 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 Cordón 
Caulle rift zone. The Cordón Caulle geothermal area, occupying a 6 x 13 
km wide volc
 ano-tectonic depression, is the largest active geothermal area of the southern Andes volcanic zone.


Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/





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


Based on information from JMA, the Tokyo VAAC reported that on 22 and 24
 February explosions from Sakura-jima produced plumes that rose to 
altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted 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 22-24 and 27-28 February explosions from 
Santa María's Santiaguito lava-dome complex generated ash plumes that 
rose 600-1,300 m above the complex and drifted WSW, W, and WNW. 
Pyroclastic flows were generated during 22-23 February, and ash fall was
 reported in El Rosario (45 km SW), Monte Bello (S), Palajunoj (SW), and
 Quetzaltenango (18 km WNW) on 23 February. Clouds of gas and tephra 
were also observed on 23 February. Constant avalanches descended the S 
flank during 23-24 and 27-28 February. Ash fall was reported in Monte 
Claro (S), San Marcos (46 km NW), Buena Vista (49 km NW), El Rosario, 
Monte Bello, and Palajunoj during 24 and 27-28 February. White plumes 
rose from the Caliente Cone and drifted WSW on 27 February.


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.


Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/geofisica/vulcanologia/boletin%20formato.htm






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


KVERT reported that during 17-24 February low levels of seismic activity
 were detected at Shiveluch and satellite imagery showed a weak thermal 
anomaly. According to visual and satellite observations, a viscous lava 
flow continued to effuse in the crater that was formed during a 2010 
eruption. Moderate fumarolic activity at the lava dome was observed 
during 19-23 February; 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/updates.php

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