Smithsonian/USGS Weekly Volcanic Activity Report 5-11 December 2012
From: "Kuhn, Sally" <KUHNS@xxxxxx>
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Smithsonian/USGS Weekly Volcanic Activity Report
5-11 December 2012
Sally Kuhn Sennert - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Chirpoi, Kuril Islands (Russia) | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Langila, New Britain | Lokon-Empung, Sulawesi | Paluweh, Lesser Sunda Islands (Indonesia) | Reventador, Ecuador | Santa María, Guatemala | Tolbachik, Central Kamchatka (Russia) | Ulawun, New Britain | White Island, New Zealand
Ongoing Activity: | Karymsky, Eastern Kamchatka (Russia) | Kizimen, Eastern Kamchatka (Russia) | Manam, Northeast of New Guinea (SW Pacific) | Pagan, Mariana Islands | Popocatépetl, México | 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
CHIRPOI Kuril Islands (Russia) 46.525°N, 150.875°E; summit elev. 742 m
SVERT reported that a thermal anomaly was detected over Snow, a volcano of Chirpoi, during 3-4, 6, and 8 December; cloud cover prevented observations of the volcano on other days during 2-10 December.
Geologic Summary. Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. Two volcanoes on Chirpoi Island have been historically active. The symmetrical Cherny volcano, which forms the 691 m high point of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No historical eruptions are known from 742-m-high Brat Chirpoev, but its youthful morphology suggests recent strombolian activity.
Source: Sakhalin Volcanic Eruption Response Team (SVERT) http://www.imgg.ru/en/home.html
KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m
During 5-11 December HVO reported that on most days the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.
At Pu'u 'O'o Crater, lava circulated within the perched lava lake at the NE part of the crater, and glow emanated both from spatter cones on the SE part of the crater floor and from a spatter cone at the NW edge. The lava lake briefly overflowed on 5 December, and small, short-lived lava flows emanated from the spatter cones during 7-9 December. Through the week a spatter cone formed over the lava lake, covering the surface.
Lava flows remained active in two branches on the coastal plain: a small W branch, and a larger E branch with scattered activity extending from the pali to the coast E of the easternmost boundary of Hawai'i Volcanoes National Park. An ocean entry was marked by a weak and variable plume near Kupapa'u, with lava entering the water in at least two different areas.
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/
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported that during 30 November-7 December video footage and satellite imagery showed Strombolian explosions at Kliuchevskoi, along with crater incandescence and gas-and-steam emissions. A weak thermal anomaly was detected in satellite images during 1 and 4-6 December; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.
Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 7,000 years ago, the beautifully symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. More than 100 flank eruptions, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation, have occurred during the past 3,000 years. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included major explosive and effusive events from flank craters.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php
LANGILA New Britain 5.525°S, 148.42°E; summit elev. 1330 m
Based on analyses of satellite imagery, the Darwin VAAC reported that an ash plume from Langila rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 110 km NW on 5 December. Elevated sulfur dioxide concentrations were also detected.
Geologic Summary. Langila, one of the most active volcanoes of New Britain, consists of a group of four small overlapping composite cones on the lower eastern flank of the extinct Talawe volcano. Talawe is the highest volcano in the Cape Gloucester area of NW New Britain. A rectangular, 2.5-km-long crater is breached widely to the SE; Langila volcano was constructed NE of the breached crater of Talawe. An extensive lava field reaches the coast on the N and NE sides of Langila. Frequent mild-to-moderate explosive eruptions, sometimes accompanied by lava flows, have been recorded since the 19th century from three active craters at the summit of Langila. The youngest and smallest crater (no. 3 crater) was formed in 1960 and has a diameter of 150 m.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/
LOKON-EMPUNG Sulawesi 1.358°N, 124.792°E; summit elev. 1580 m
Based on information from CVGHM and the WAAA MWO (in Ujung Pandang, Indonesia), the Darwin VAAC reported that an eruption from Lokon-Empung produced an ash plume that rose to an altitude of 3.4 km (11,000 ft) a.s.l. on 6 December and drifted S. Ash was not detected in satellite imagery. On 10 December a plume rose to an altitude of 4.3 km (14,000 ft) a.s.l.
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.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/
PALUWEH Lesser Sunda Islands (Indonesia) 8.32°S, 121.708°E; summit elev. 875 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 6 and 8 December ash plumes from Paluweh rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 35-75 km NW, W, and SW.
Geologic Summary. Paluweh volcano, also known as Rokatenda, forms the 8-km-wide island of Paluweh N of the volcanic arc that cuts across Flores Island. Although the volcano rises about 3,000 m above the sea floor, its summit reaches only 875 m above sea level. The broad irregular summit region contains overlapping craters up to 900 m wide and several lava domes. Several flank vents occur along a NW-trending fissure. The largest historical eruption of Paluweh occurred in 1928, when a strong explosive eruption was accompanied by landslide-induced tsunamis and lava-dome emplacement.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) ftp://ftp.bom.gov.au/anon/gen/vaac/
REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m
IG reported that seismicity at Reventador was high during 5-11 December and indicated multiple explosions almost daily. Plumes were observed although cloud cover often prevented visual observations. On 5 December a steam plume rose 1.5 km and drifted NW. The next day a steam-and-ash plume rose 2 km above the lava dome and drifted SE. A steam-and-ash plume rose 1 km on 8 December and drifted WSW, towards Chaco. Another steam-and-ash plume was observed on 11 December.
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.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG) http://www.igepn.edu.ec/
SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m
INSIVUMEH reported that during 6-7 December incandescence from Santa María's Santiaguito lava-dome complex was visible, and an explosion generated an ash plume that rose 300 m and drifted E. During 8-11 December avalanches were produced from the fronts of lava flows on the SE, S, and SW flanks. A recent lava flow traveled 700 m down the S flank. Ash plumes that rose from the avalanches drifted 10 km W and SW. Crater incandescence was observed at night. A special bulletin on 11 December noted that a new lava flow had traveled down the N flank. Crater incandescence continued to be observed at night.
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/
TOLBACHIK Central Kamchatka (Russia) 55.830°N, 160.330°E; summit elev. 3682 m
KVERT reported that the eruption from Tolbachik that began on 27 November continued through 8 December. A very large thermal anomaly on the N part of Tolbachinsky Dol, a lava plateau on the SW side of the volcano, was reported daily. Lava effused from two fissures along the W side of Tolbachinsky Dol; lava had flowed 17-20 km away from the S fissure by 7 December. Ash plumes rose less than 500 m during 1-5 December, and minor ashfall was reported in Kozyrevsk (40 km NW) and Klyuchi (65 km NW) villages on 3 December. Gas-and-steam plumes drifted 250 km SE on 5 December, and rose as high as 1 km during 7-11 December and drifted SW and W. The Aviation Color Code remained at Orange.
Geologic Summary. The massive Tolbachik basaltic volcano is located at the southern end of the dominantly andesitic Kliuchevskaya volcano group. The Tolbachik massif is composed of two overlapping, but morphologically dissimilar volcanoes. The flat-topped Plosky Tolbachik shield volcano with its nested Holocene Hawaiian-type calderas up to 3 km in diameter is located east of the older and higher sharp-topped Ostry Tolbachik stratovolcano. The summit caldera at Plosky Tolbachik was formed in association with major lava effusion about 6500 years ago and simultaneously with a major southward-directed sector collapse of Ostry Tolbachik volcano. Lengthy rift zones extending NE and SSW of the volcano have erupted voluminous basaltic lava flows during the Holocene, with activity during the past two thousand years being confined to the narrow axial zone of the rifts. The 1975-76 eruption originating from the SSW-flank fissure system and the summit was the largest historical basaltic eruption in Kamchatka.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php
ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m
RVO reported that dense gray-brown ash plumes continued to rise 200 m from Ulawun during 1-7 December. Ashfall was reported on the NW flanks, in Ubili (10 km NW) and Ulamona (10 km NW). A small landslide scar appeared near the N valley flank vent, reportedly caused by movement of a large boulder and loose material, triggered by a M 6.1 earthquake that occurred near Pomio (55 km SSE) on 19 November.
Geologic Summary. The symmetrical basaltic to andesitic Ulawun stratovolcano is the highest volcano of the Bismarck arc, and one of Papua New Guinea's most frequently active. Ulawun rises above the N coast of New Britain opposite Bamus volcano. The upper 1,000 m of the 2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW side of the volcano, and a flank lava-flow complex lies to the S of this valley. Historical eruptions date back to the beginning of the 18th century. Twentieth-century eruptions were mildly explosive until 1967, but after 1970 several larger eruptions produced lava flows and basaltic pyroclastic flows, greatly modifying the summit crater.
Source: Rabaul Volcano Observatory (RVO)
WHITE ISLAND New Zealand 37.52°S, 177.18°E; summit elev. 321 m
On 12 December the GeoNet Data Centre posted a report describing a new lava dome at White Island that volcanologists recently noticed. The spiny lava dome was 20-30 m in diameter and grew in a crater formed during an eruption on 5 August. A prominent steam plume rose from the dome. Comments from tour operators at White Island suggested that the dome may have been visible two weeks earlier, but not as clearly as on 10 December. The Alert Level was raised to 2 (on a scale of 0-5), and the Aviation Colour Code was raised to Orange (second highest on a four-color scale).
Geologic Summary. The uninhabited 2 x 2.4 km White Island, one of New Zealand's most active volcanoes, is the emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The 321-m-high island consists of two overlapping stratovolcanoes; the summit crater appears to be breached to the SE because the shoreline corresponds to the level of several notches in the SE crater wall. Throughout the short historical period beginning in 1826 the volcano has had long periods of continuous hydrothermal activity and steam release, punctuated by small-to-medium eruptions. Its activity also forms a prominent part of Maori legends. The most recent eruptive episode, which began on 7 March 2000, included the largest eruption at White Island in the past 20 years on 27 July.
Source: GeoNet Data Centre http://www.geonet.org.nz/
Ongoing Activity
KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that weak-to-moderate seismic activity at Karymsky was detected during 29 November-7 December. Seismic data indicated that ash plumes possibly rose to an altitude of 3 km (9,800 ft) a.s.l. during 29-30 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
KIZIMEN Eastern Kamchatka (Russia) 55.130°N, 160.32°E; summit elev. 2376 m
KVERT reported that during 30 November-7 December weak-to-moderate seismic activity at Kizimen was detected. Video and satellite images showed lava flows effusing from the summit and the E flank, summit incandescence, strong gas-and-steam activity, and hot avalanches on the S flank. A thermal anomaly was detected in satellite images during 1 and 4-7 December; cloud cover obscured views on the other days. 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
MANAM Northeast of New Guinea (SW Pacific) 4.080°S, 145.037°E; summit elev. 1807 m
RVO reported that during 1-7 December both diffuse and dense ash plumes rose 500 m above Manam's Southern Crater and drifted NW. Ashfall was reported in areas downwind. Roaring and rumbling were heard, and became loud and frequent on 4 December. Ejected incandescent tephra was observed at night, and a small volume of lava effused from a SE valley vent that formed in August. Small volumes of lava also flowed from a vent, adjacent to the first vent, which opened in late November. White vapor plumes rose from Main Crater during the reporting period. Data from the electronic tiltmeter showed a long-term inflationary trend towards the E. RVO warned residents to stay away from the four main radial valleys, especially to the SE and SW, because products of the current activity are channeled into them.
Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys," regularly spaced 90 degrees apart, channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE avalanche valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded at Manam since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Source: Rabaul Volcano Observatory (RVO)
PAGAN Mariana Islands 18.13°N, 145.80°E; summit elev. 570 m
Satellite imagery showed a plume drifting from Pagan during 1-7 December. On 29 November observers in Saipan reported hazy sky conditions associated with N winds that pushed the gas-and-vapor plume from Pagan S. Since then, no additional reports of haze or vog associated with the Pagan plume were noted.
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 caldera, which probably formed during the early Holocene. 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/
POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m
CENAPRED reported that during 4-11 December seismicity at Popocatépetl indicated continuing gas-and-steam emissions that contained minor amounts of ash. Incandescence from the crater was observed at night. Cloud cover often prevented observations; gas-and-steam plumes were observed drifting NE, E, and SSE during periods of clearer weather. Ash plumes observed during 7-8 December rose at most 1 km and drifted NE. The Alert Level remained at Yellow, Phase Two.
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/es/
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
JMA reported that during 3-7 December explosions from Sakura-jima's Showa Crater ejected tephra as far as 1.3 km from the crater. A very small eruption occurred at Minami-dake Crater on 6 December. Based on information from JMA, the Tokyo VAAC reported that explosions during 5-10 December often produced plumes that rose to altitudes of 1.2-4.3 km (4,000-14,000 ft) a.s.l. and drifted SW, S, SE, and E. A pilot reported that an ash plume drifted E at an altitude of 2.1 km (7,000 ft) a.s.l. on 7 December.
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.
Sources: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/index.html,
Tokyo Volcanic Ash Advisory Center (VAAC) http://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
Based on visual observations and analyses of satellite data, KVERT reported that during 30 November-7 December a viscous lava flow continued to effuse on the NW flank of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, and fumarolic activity. Satellite imagery showed a thermal anomaly on the lava dome during 29 November and 3-6 December; cloud cover obscured views on the other days. 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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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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