Smithsonian/USGS Weekly Volcanic Activity Report 8-14 February 2012
From: "Faulk, Elisabeth" <FaulkE@xxxxxx>
*****************************************************************************************
Smithsonian/USGS Weekly Volcanic Activity Report
8-14 February 2012
Elisabeth Faulk - Weekly Report Editor
faulke@xxxxxx
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Cleveland, Chuginadak Island | Galunggung, Western Java (Indonesia) | Ijen, Eastern Java (Indonesia) | Lokon-Empung, Sulawesi | Reventador, Ecuador
Ongoing Activity: | Etna, Sicily (Italy) | 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 | 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 during 8-14 February there were no observations of elevated surface temperatures or ash emissions from Cleveland because of partly cloudy conditions. On 10 February satellite observations revealed that the lava dome had grown to about 50 m in diameter. 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/
GALUNGGUNG Western Java (Indonesia) 7.25°S, 108.058°E; summit elev. 2168 m
On 13 February, CVGHM reported that from September 2011 to 8 February 2012 discolorations in the crater lake water at Galunggung were observed. In addition, a sudden increase in water temperature was measured, from 27 degrees Celsius on 5 February to 40 degrees on 8 February. Based on seismic data and crater lake observations, CVGHM raised the Alert Level from 1 to 2 (on a scale of 1-4) on 12 February and recommended staying at least 500 m away from the lake shore.
Geologic Summary. The forested slopes of 2,168-m-high Galunggung volcano in western Java are cut by a large horseshoe-shaped caldera breached to the SE that has served to channel the products of recent eruptions in that direction. The "Ten Thousand Hills of Tasikmalaya" dotting the plain below the volcano are debris-avalanche hummocks from the collapse that formed the breached caldera about 4,200 years ago. Although historical eruptions, restricted to the central vent near the caldera headwall, have been infrequent, they have caused much devastation. The first historical eruption in 1822 produced pyroclastic flows and lahars that killed over 4,000 persons. More recently, a strong explosive eruption during 1982-1983 caused severe economic disruption to populated areas near the volcano.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/
IJEN Eastern Java (Indonesia) 8.058°S, 114.242°E; summit elev. 2799 m
CVGHM lowered the Alert Level for Ijen from 3 to 2 (on a scale of 1-4) on 8 February based on decreased seismicity and visual observations of white plumes rising as high as 300 m above the crater. In addition, a decrease in lake water temperature was measured, which ranged from 42 degrees Celsius on 20 January to 37 degrees on 2 February.
Geologic Summary. The Ijen volcano complex consists of a group of small stratovolcanoes constructed within the large 20-km-wide Ijen (Kendeng) caldera. The N caldera wall forms a prominent arcuate ridge, but elsewhere the caldera rim is buried by post-caldera volcanoes, including Gunung Merapi stratovolcano, which forms the 2,799 m high point of the Ijen complex. Immediately W of Gunung Merapi is the renowned historically active Kawah Ijen volcano, which contains a nearly 1-km-wide, turquoise-colored, acid crater lake. The picturesque lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are hand-carried from the crater floor. A half dozen small-to-moderate phreatic eruptions have taken place from Kawah Ijen during the 20th century.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://www.vsi.esdm.go.id/
LOKON-EMPUNG Sulawesi 1.358°N, 124.792°E; summit elev. 1580 m
According to news articles, an explosion from the Tompaluan crater, in the saddle between the Lokon-Empung peaks, produced an ash plume that rose as high as 2 km above the crater on 10 February; loud "thumping" noises were also heard. Based on information from CVGHM, the Darwin VAAC reported ash plumes that rose to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l. during 10-12 February, though clouds prevented the detection of ash in satellite imagery.
Geologic Summary. The twin volcanoes Lokon and Empung, rising about 800 m above the plain of Tondano, are among the most active volcanoes of Sulawesi. Lokon, the higher of the two peaks (whose summits are only 2.2 km apart) has a flat, craterless top. The morphologically younger Empung volcano has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century, but all subsequent eruptions have originated from Tompaluan, a 150 x 250 m wide double crater situated in the saddle between the two peaks. Historical eruptions have primarily produced small-to-moderate ash plumes that have occasionally damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html, CNN News http://www.cnn.com/2012/02/09/world/asia/indonesia-volcano-eruption/index.html, Antara News http://www.antaranews.com/en/news/79784/mount-lokon-erupts-again
REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m
IG reported that during 10-13 February new activity from Reventador was detected. Satellite images showed a thermal anomaly on 10 February. Based on pilot observations, the Washington VAAC reported an ash plume that rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted NW. On 11 February ash-and-steam emissions drifted NW. Seismicity increased on 12 February and a lava flow descended the NE flank during 12-13 February. Crater incandescence was observed during 10-13 February.
Geologic Summary. Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well E of the principal volcanic axis. It is a forested stratovolcano that rises above the remote jungles of the western Amazon basin. A 3-km-wide caldera breached to the E was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1,300 m above the caldera floor. Reventador has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG) http://www.igepn.edu.ec/, Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
Ongoing Activity
ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m
Sezione di Catania - Osservatorio Etneo reported that on 8 February the New SE Crater (New SEC) of Etna entered another paroxysmal eruption episode after about 12 days of Strombolian activity. During the afternoon of 8 February, the Strombolian activity increased in both frequency and intensity of explosions from the vent on the W portion of the crater floor, and occasionally from a vent to the E. After about 1900, lava began to spill into the deep breach on the SE crater rim and then descended to the base of the cone. The lava flow expanded around 2100 and the Strombolian activity slowly increased, turning into a discontinuous lava fountain around 2330.
On 9 February the pulsating lava fountain rose 100-500 m above the crater before a continuous jet rising 300-400 m above the crater. A cloud with a small amount of tephra rose 6 km above the summit and then drifted W, producing some pyroclastic fallout that was on the upper portion of the volcano. Around 0200 and 0400, lava fountains from the two vents within the crater rose as high as 500 m above the crater. The fountain from the E vent caused abundant fallout on the crater rim and E flank. A third vent, located in the breach cutting the SE crater rim, produced sporadic violent explosions that ejected bombs many meters in diameter all over the E portion of the cone.
The lava flow reached the W rim around 0130, descended the flank, and branched into three different flows that reached a distance of 3 km from the New SEC. Lava fountaining started to diminish around 0530, and then around 0545 sporadic jets rose as high as 300 m above the crater. At the same time, the vent in the SE crater breach produced strong explosions that again ejected bombs many meters in diameter. These explosions generated loud bangs that were heard all over Etna and small ash emissions that were reported on the W portion of Bocca Nuova. Around 0900 activity started to diminish and ceased abruptly at 1000.
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.
Source: Sezione di Catania - Osservatorio Etneo http://www.ct.ingv.it/index.php
HIERRO Canary Islands (Spain) 27.73°N, 18.03°W; summit elev. 1500 m
Instituto Geográfico Nacional (IGN) reported that during 8-14 February the submarine eruption continued S of El Hierro Island. The mean amplitude of the tremor remained low overall, but was variable. Very few emissions of lava fragments were observed over the vent area.
Fifty seven seismic events were registered during this period, most of them located in the central part of the island, with offshore events extending to the S. Depths of the hypocenters varied mainly between 6 and 17 km and magnitudes between 0.6 and 2.2. GPS data pointed to a slight subsidence at some of the stations.
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/resources/volcanologia/html/informesHIERRO.html
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 3-10 February and indicated that ash plumes possibly rose to an altitude of 4.1 km (13,500 ft) a.s.l. Satellite imagery showed a thermal anomaly at the volcano all week and an ash cloud 3 km long by 7 km wide that drifted 10 km SE on 6 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 8-14 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor, and strongest from a small cone on the NE edge during 8-13 February. A web camera recorded incandescence above the pali on 8 and during 12-14 February. The SE vent issued short lava flows on 14 February.
In comparison to last week, thermal anomalies increased on the flow field during 8-9 February. HVO geologists aboard an overflight on 9 February reported that the small cone on the NE edge had collapsed and was venting hot gas, and the pit was filled with a stream of lava heading NE. Geologists mapped active flows on the flow field about 6 km SE of Pu'u 'O'o and above the abandoned Royal Gardens subdivision. Web camera and satellite images indicated that the flows remained active 6 km SE of Pu'u 'O'o and above the abandoned Royal Gardens subdivision during 10-14 February, and from the Kalapana (E side of the coastal plain) on 13 February. Ground based observers reported active lava at the top of the pali on 11 and 13-14 February.
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 3-10 February 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. Video data showed strong gas-and-steam activity all week. 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 8-14 February steam-and-gas emissions rose from Popocatépetl; some of the emissions contained small amounts of ash on 14 February. Crater incandescence was observed during the morning of 8 and 14 February and from the S on 13 February. Clouds prevented views during 9-12 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 8-13 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. During 8-11and 13 February plumes observed with a web camera rose 1-3 km above the crater; clouds prevented views on 12 February. Satellite images showed ash plumes drifting 20-90 km N, NE, ENE, E, ESE, and SSE during 8-13 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 during 8-14 February explosions from Sakura-jima produced plumes that rose to altitudes of 1-3 km (3,000-10,000 ft) a.s.l. and drifted E and SE. On 11 February an ash plume that rose to an altitude of 2.4 km (8,000 ft) a.s.l., drifted E, and later dissipated. A pilot observation indicated an ash plume rising to an altitude of 1.8 km (6,000 ft) a.s.l. and drifting NE on 11 February.
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
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that low levels of seismic activity were detected at Shiveluch 3-10 February. 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 that was formed during a 2010 eruption. Moderate fumarolic activity at the lava dome and occasional hot avalanches were observed all 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
==============================================================
Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI).
ASU - http://www.asu.edu/ PSU - http://pdx.edu/ GVP - http://www.volcano.si.edu/ IAVCEI - http://www.iavcei.org/
To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx.
To contribute to the volcano list, send your message to: volcano@xxxxxxx. Please do not send attachments.
==============================================================
