Smithsonian/USGS Weekly Volcanic Activity Report 30 November-6 December 2011
From: "Faulk, Elisabeth" <FaulkE@xxxxxx>
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Smithsonian/USGS Weekly Volcanic Activity Report
30 November-6 December 2011
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Fuego, Guatemala | Galeras, Colombia | Gamalama, Indonesia | Pagan, Mariana Islands | Tungurahua, Ecuador
Ongoing Activity: | Dukono, Halmahera | 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)
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
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
INSIVUMEH reported that on 1 December explosions from Fuego produced ash plumes that rose 800 m above the crater and drifted to the S. Avalanches descended toward Ash Creek. During 5-6 December ash plumes rose to altitudes of 400-500 m above the crater and drifted to the W. A 150-m-long lava flow descended toward Ash Creek and avalanches reached vegetated areas.
Based on information from INSIVUMEH, the Washington VAAC reported gas and ash emissions on 2 December and a possible ash plume rose to an altitude of 3 km (10,000 ft) a.s.l. on 6 December.
Geologic Summary. Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta volcano dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta volcano may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango volcano, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC) http://www.insivumeh.gob.gt/geofisica/vulcanologia/boletin%20formato.htm, http://www.ssd.noaa.gov/VAAC/messages.html
GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4276 m
INGEOMINAS reported that observations of Galeras during an overflight on 29 November revealed thermal anomalies in the main crater. During an overflight on 6 December scientists observed that gas emissions rose from the main crater and two craters to the N and SW (Paisita and Chavas, respectively), and had increased in comparison to the previous week. Thermal anomalies were also detected in the main crater. INGEOMINAS raised the Alert Level to III (Yellow; "changes in the behavior of volcanic activity”) on 6 December.
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 Geología y Minería (INGEOMINAS) http://www.ingeominas.gov.co/
GAMALAMA Indonesia 0.80°N, 127.33°E; summit elev. 1715 m
CVGHM raised the Alert Level for Gamalama from 2 to 3 (on a scale of 1-4) on 4 December based on seismicity and visual observations during 1-4 December. On 1 and 4 December white plumes rose 150 m (492 ft) above the summit and drifted W. Clouds obscured views on the other days.
Based on information from CVGHM, the Darwin VAAC reported that during 5-6 December ash plumes from Gamalama rose to altitudes of 2.4-3.0 km (8,000-10,000 ft) a.s.l. and drifted SE.
Geologic Summary. Gamalama (Peak of Ternate) is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera and is one of Indonesia's most active volcanoes. The island of Ternate was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the thorough documentation of Gamalama's historical activity. Three cones, progressively younger to the north, form the summit of Gamalama, which reaches 1715 m. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano. Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63.
Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Washington Volcanic Ash Advisory Center (VAAC) http://www.vsi.esdm.go.id/, http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
PAGAN Mariana Islands 18.13°N, 145.80°E; summit elev. 570 m
A Northern Mariana Islands status report noted that clear to partly-cloudy satellite images showed a persistent gas-and-steam plume drifting from Pagan during 25 November-2 December. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Geologic Summary. Pagan Island, the largest and one of the most active of the Mariana Islands volcanoes, consists of two stratovolcanoes connected by a narrow isthmus. Both North and South Pagan stratovolcanoes were constructed within calderas, 7 and 4 km in diameter, respectively. The 570-m-high Mount Pagan at the NE end of the island rises above the flat floor of the northern caldera, which may have formed less than 1000 years ago. South Pagan is a 548-m-high stratovolcano with an elongated summit containing four distinct craters. Almost all of the historical eruptions of Pagan, which date back to the 17th century, have originated from North Pagan volcano. The largest eruption of Pagan during historical time took place in 1981 and prompted the evacuation of the sparsely populated island.
Source: Emergency Management Office of the Commonwealth of the Mariana Islands, Office of the Governor, United States Geological Survey Volcano Hazards Program. http://volcanoes.usgs.gov/nmi/activity/index.php
TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m
IG reported that seismicity remained unchanged from the previous week at Tungurahua, but the number of explosions had increased during 30 November-6 December. Incandescent blocks traveled 1 km down the flanks, and roaring noises and sounds resembling "cannon shots" were reported all week. Ashfall was reported in most communities near the volcano during the week. Ash plumes rose to altitudes of 1.5-5.0 km (4,920-16,400 ft) and drifted in multiple directions. Activity on the night of 2 December included lahars and ejections of incandescent blocks 500 m above the crater.
Seismicity increased on 3 December. During 3-5 December pyroclastic flows descended on the W flanks. Pyroclastic flows were also reported on the NW flank on 4 December, and large explosions occurred at 0130, 0600, and 1330. Significant ashfall was reported in San Juan, Manzano (8 km SW), and Bilbao (8 km W). On 5 December incandescent blocks were ejected 300 m above the crater and gray ash was deposited mainly to the E. On 6 December incandescence and Strombolian activity was observed.
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
DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 29 November ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 65 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 Geográfico Nacional (IGN) reported that during 30 November–6 December the submarine eruption continued S of El Hierro Island, with lava balloons sporadically observed floating on the sea. During this period, the mean tremor amplitude was similar to the previous week. Twenty-eight seismic events were located, most of them offshore to the N of the island at depths of 15-24 km and with a maximum magnitude of 2.8. Only one of these events was felt by residents at a maximum intensity value of II using EMS-98 (European Macroseismic Scale). GPS data analyses showed stability in the horizontal components; the vertical component at stations located on the S and NE parts of the island showed subsidence.
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.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 25 November-2 December, and indicated that possible ash plumes rose to an altitude of 3.8 km (12,500 ft) a.s.l. during the week. Satellite imagery showed a thermal anomaly on the volcano during 28 November-1 December. 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 30 November-6 December, 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.
On 2 December incandescence was seen from a new area low on the N flank of Pu’u’O’o. Pahoehoe flows, fed through lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o based on intermittent views from satellite, ground observers and an overflight on 3 December. During 4-5 December the vent on the E edge of the crater produced lava flows that partially filled the depression left by the flank fissure eruption in September and a perched lava lake was built on 6 December.
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 a decrease in seismic activity at Kizimen during 25 November-2 December and a thermal anomaly that was detected daily in satellite images. A large lava flow on the NE and E flanks continued to effuse. The video camera was not operating due to technical reasons during the week. Pilot reports indicated gas-and-steam activity during 27-28 November, and plumes rose to an altitude of 5 km (16,400 ft) a.s.l. 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 México 19.023°N, 98.622°W; summit elev. 5426 m
CENAPRED reported that during 30 November-6 December steam-and-gas emissions rose from Popocatépetl and crater incandescence was observed during most nights and early mornings. Steam-and-gas emissions occasionally contained small amounts of ash on 30 November and 5 December.
Based on information from the Mexico City MWO, the Washington VAAC reported that an ash plume rose to an altitude of 6.7 km (22,000 ft) a.s.l. and drifted NE on 5 December. That same day satellite imagery showed that the ash plume had dissipated.
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.
Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC) http://www.cenapred.unam.mx/es/, http://www.ssd.noaa.gov/VAAC/messages.html
PUYEHUE-CORDON CAULLE Central Chile 40.590°S, 72.117°W; summit elev. 2236 m
Based on seismicity during 30 November-6 December, 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 1-3 and 5 December plumes observed with the web camera rose 1.5-3 km above the crater. On 1 December satellite imagery showed an ash plume drifting 90 km SSE with sparse ashfall to the W and NW and dissipated 100 km to the SE. During the night the crater was incandescent. Satellite imagery showed an ash plume drifting E and SE and reaching the Atlantic Ocean on 2 December. Cloud cover prevented satellite observations during 3-4 December. On 5 December satellite imagery showed a plume drifting 100 km NW. 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 volcano-tectonic depression, is the largest active geothermal area of the southern Andes volcanic zone.
Sources: 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 30 November and 2-6 December explosions from Sakura-jima produced plumes that rose to altitudes of 1.2-3.0 km (4,000-10,000 ft) a.s.l. and drifted NE, E, SE, W, NW. Satellite imagery and a pilot reports on 30 November and 5 December indicated ash plumes to an altitude of 3.7 km (12,000 ft) a.s.l that drifted 37 km SE and 74 km S, respectively.
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 moderate seismic activity was detected at Shiveluch during 25 November-2 December, 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. A gas-and-steam plume detected in satellite imagery drifted 22 km NW on 26 November. Moderate fumarolic activity at the lava dome was observed during 28-29 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
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