************************************************************************************
Smithsonian/USGS Weekly Volcanic Activity Report 8-14 December 2010
From: "Venzke, Ed" <VENZKEE@xxxxxx>
************************************************************************************
Smithsonian/USGS Weekly Volcanic Activity Report
8-14 December 2010
Sally Kuhn Sennert - Weekly Report Editor
kuhns@xxxxxx
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Kizimen, Eastern Kamchatka (Russia) | Kliuchevskoi, Central Kamchatka (Russia) | Piton de la Fournaise, Reunion Island | Tungurahua, Ecuador
Ongoing Activity: | Bezymianny, Central Kamchatka (Russia) | Bulusan, Luzon | Fuego, Guatemala | Karangetang [Api Siau], Siau I | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Pacaya, Guatemala | Sakura-jima, Kyushu | Santa María, Guatemala | Shiveluch, Central Kamchatka (Russia) | Soufrière Hills, Montserrat
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
KIZIMEN Eastern Kamchatka (Russia) 55.130°N, 160.32°E; summit elev. 2376 m
KVERT reported that during 3-8 December seismicity at Kizimen was above background levels. An increase in seismicity reported on 9 December was possibly caused by snow avalanches. That same day, the Tokyo VAAC reported that according to KEMSD an eruption produced a plume that rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted N. Ash was not identified in satellite images. The Level of Aviation Color Code remained at Yellow.
On 9 December, seismicity significantly increased and the Aviation Color Code level was raised to Orange. A bright thermal anomaly was observed in satellite imagery the next day. On 13 December an explosive eruption generated ash plumes that rose to altitudes of 3-3.5 km (9,800-11,500 ft) a.s.l. and drifted NW. Based on information from KEMSD and analysis of satellite imagery, the Tokyo VAAC reported that an ash plume rose to an altitude of 10 km (33,000 ft) a.s.l. and drifted N. KVERT noted that lightning in the ash plumes was observed. The Aviation Color Code was raised to Red. Ash deposits in Kozyrevsk and Tigil, 110 and 308 km NW, respectively, were 5 mm thick. Later that day seismic activity decreased; the Aviation Color Code was lowered to 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.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported that during 3-10 December seismic activity at Kliuchevskoi was slightly above background levels. Satellite imagery showed a weak thermal anomaly over the crater during 3 and 6-8 December. Gas-and-steam plumes sometimes containing ash were observed during 3-4 and 8-9 December. The Aviation Color Code level 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)
PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev. 2632 m
On 9 December, OVPDLF reported that a seismic crisis at Piton de la Fournaise was followed by inflation of the entire summit region. Many small landslides occurred in Dolomieu crater. Later that day lava flows from two fissures on the N flank of Piton de la Fournaise, about 1 km NW of Dolomieu crater rim, traveled about 1.5 km N and NW. The next day seismicity and deformation measurements indicated that eruption of lava had stopped.
Geologic Summary. Massive Piton de la Fournaise shield volcano on the island of Réunion is one of the world's most active volcanoes. Most historical eruptions have originated from the summit and flanks of a 400-m-high lava shield, Dolomieu, that has grown within the youngest of three large calderas. This depression is 8 km wide and is breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows within the caldera, have been documented since the 17th century. The volcano is monitored by the Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPDLF)
TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m
During 7-14 December, IG reported that ash-and-steam plumes from Tungurahua rose to altitudes of 6-9 km (19,700-30,000 ft) a.s.l. and drifted WNW, W, SSW, and SW. Ashfall was reported in areas as far as 8 km NW, 15 km W and SW, and 30 km S. Roars and sounds resembling "cannon shots" were noted almost daily. Explosions often caused windows and structures to vibrate. At night during 7-8 December Strombolian explosions ejected material 600 m above the crater. Blocks rolled 600-800 m down the flanks. On 9 December a pyroclastic flow traveled 3 km down the NW flank. During 9-10 and 12 December incandescent blocks rolled down the flanks. During 12-13 December incandescent blocks were ejected 500 m above the crater.
On 14 December, IG issued a special report stating that a lava flow with an estimated volume of hundreds of thousands of cubic meters traveled 1 km down the W flank on 4 December. The report noted that the flow was the second since the eruptions onset in 1999.
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)
Ongoing Activity
BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit elev. 2882 m
KVERT reported that, based on air photos taken of Bezymianny by helicopter on 21 November, a new area of lava possibly had extruded from the top of the lava dome. During 3-10 December seismicity did not exceed background levels. On 3 and 7 December gas-and-steam emissions were seen, the same days a weak thermal anomaly was detected in satellite imagery. The Aviation Color Code level remained at Yellow.
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)
BULUSAN Luzon 12.770°N, 124.05°E; summit elev. 1565 m
During 8-12 December, PHIVOLCS reported that 1-2 volcanic earthquakes from Bulusan were detected by the seismic network. Cloud cover prevented visual observations. On 13 December, 7 volcanic earthquakes were detected. Steam rose from the crater and known thermal vents. The Alert Level remained at 1 (on a scale of 0-5).
Geologic Summary. Luzon's southernmost volcano, Bulusan, was constructed within the 11-km-diameter dacitic Irosin caldera, which was formed more than 36,000 years ago. A broad, flat moat is located below the prominent SW caldera rim; the NE rim is buried by the andesitic Bulusan complex. Bulusan is flanked by several other large intracaldera lava domes and cones, including the prominent Mount Jormajan lava dome on the SW flank and Sharp Peak to the NE. The summit of Bulusan volcano is unvegetated and contains a 300-m-wide, 50-m-deep crater. Three small craters are located on the SE flank. Many moderate explosive eruptions have been recorded at Bulusan since the mid-19th century.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
On 8 December, INSIVUMEH reported that explosions from Fuego produced ash plumes that rose 500 m above the crater and drifted S and SW. The Washington VAAC stated that on 10 December an ash plume was observed in satellite imagery. During 13-14 December, INSIVUMEH again reported explosions; ash plumes rose 400-900 m above the crater and drifted S and SE. Some of the explosions were heard 10 km away and generated shock waves that rattled structures nearby, including Panimache (8 km SW), Morelia (10 km SW), Santa Sofía, and Yucales (12 km SW). Avalanches descended the S and W flanks. At night, incandescent material was ejected 100 m high.
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 3,763-m-high Fuego and its twin volcano to the N, Acatenango. Construction of Meseta volcano continued until the late Pleistocene or early Holocene, after which growth of the modern Fuego volcano continued the southward migration of volcanism that began at Acatenango. 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. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)
KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m
CVGHM reported that during November until 12 December observers at the station at Salili, S of the volcano, noted a drastic decrease in the occurrence of pyroclastic flows on Karangetang's flanks. Seismicity also decreased, and white plumes rose up to 300 m above the craters. The Alert Level was lowered to 2 (on a scale of 1-4).
Geologic Summary. Karangetang (also known as Api Siau) lies at the northern end of the island of Siau, N of Sulawesi, and contains five summit craters strung along a N-S line. One of Indonesia's most active volcanoes, Karangetang has had more than 40 recorded eruptions since 1675. Twentieth-century eruptions have included frequent explosions, sometimes accompanied by pyroclastic flows and lahars.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)
KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that seismic activity at Karymsky was above background levels during 3-10 December. Seismic data suggested that possible ash plumes rose to an altitude of 4.5 km (14,800 ft) a.s.l. during 4-7 December. Thermal anomalies were detected in satellite imagery on 3 and 6 December. The Aviation Color Code level 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)
KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m
During 8-14 December, HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater remained mostly stable at approximately 130 m below the crater floor, periodically rising 15-20 m higher. Nighttime incandescence has been visible from the Jaggar Museum on the NW caldera rim since early 2010. A plume from the vent drifted in multiple directions and deposited ash and fresh spatter nearby.
At the east rift zone, lava flowed a short distance through the TEB lava-tube system before breaking out onto the surface at a saddle between two rootless shields at around the 610 m elevation, forming a lava pond atop a new shield. Two breakout lava flows traveled about 120 m down the pali. Lava flows from a small spatter cone on the Pu'u 'O'o crater floor continued. A small lava flow traveled W on 10 December. On 13 December lava flowed from a second spatter cone, located on the NW edge of the crater.
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)
PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m
On 8, 13, and 14 December, INSIVUMEH reported that gas-and-steam plumes rose from Pacaya's MacKenney cone and drifted SE, SW, and S, respectively.
Geologic Summary. Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex volcano constructed on the southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A cluster of dacitic lava domes occupies the caldera floor. The Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1,100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. During the past several decades, activity at Pacaya has consisted of frequent Strombolian eruptions with intermittent lava flow extrusion on the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m
Based on information from JMA and analysis of satellite imagery, the Tokyo VAAC reported that on 8 December an eruption from Sakura-jima produced an ash plume that rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted E and SE. During 11-12 December explosions produced plumes that rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted SE and E. On 12 December a pilot observed an ash plume that rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted NE and E.
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)
SANTA MARIA Guatemala 14.756°N, 91.552°W; summit elev. 3772 m
INSIVUMEH reported that on 8 December explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose 700 m above Caliente dome and drifted SE. Ashfall was reported on the SE flanks and in the village of San José. The seismic network recorded block avalanches in addition to the explosions. The Washington VAAC stated that on 10 December an ash plume was observed in satellite imagery drifting 21 km W. According to INSIVUMEH, explosions ejected ash plumes that rose 300-700 m above the crater and drifted SE on 13 December. During 13-14 December block avalanches were detected by the seismic network. On 14 December weak pyroclastic flows were observed.
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.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)
SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m
KVERT reported that moderate seismic activity from Shiveluch was detected during 3-10 December. A bright thermal anomaly over the volcano was observed in satellite imagery. Plumes composed of either gas and steam or ash were seen in satellite imagery drifting 322 km SE on 3 December. Seismic data analyses on 6 December suggested that ash plumes rose to an altitude of 5 km (16,400 ft) a.s.l. Gas-and-steam activity was observed visually during 3, 6, and 8-9 December. The Aviation Color Code level remained at Orange.
Based on analyses of satellite imagery and information from KVERT, the Tokyo VAAC reported that on 14 December an eruption produced a plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l.
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.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that during 3-10 December activity from the Soufrière Hills lava dome was at a low level. Observations from helicopter revealed fresh rockfall and pyroclastic flow deposits in the Tar River valley (E) that originated from the E face of the lava dome. On 6 December a small pyroclastic flow occurred in the 11 February collapse scar. The next day a small lahar occurred in the upper part of the Belham valley to the NW. The Hazard Level remained at 3.
Geologic Summary. The complex dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. English's Crater, a 1-km-wide crater breached widely to the E, was formed during an eruption about 4,000 years ago in which the summit collapsed, producing a large submarine debris avalanche. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits at Soufrière Hills. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but with the exception of a 17th-century eruption that produced the Castle Peak lava dome, no historical eruptions were recorded on Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.
Source: Montserrat Volcano Observatory (MVO)
==============================================================
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.
==============================================================
