*********************************** GVP/USGS Weekly Volcanic Activity Report 13-19 December 2006 http://www.volcano.si.edu/reports/usgs/ *********************************** New Activity/Unrest: | Kliuchevskoi, Russia | Shiveluch, Russia | Soputan, Indonesia Ongoing Activity: | Bulusan, Philippines | Colima, México | Etna, Italy | Home Reef, Tonga | Karymsky, Russia | Kilauea, USA | Manam, Papua New Guinea | Piton de la Fournaise, Reunion Island | Popocatépetl, México | Rabaul, Papua New Guinea | Sakura-jima, Japan | Soufrière Hills, Montserrat | St. Helens, USA | Tungurahua, Ecuador New Activity/Unrest KLIUCHEVSKOI Kamchatka Peninsula, Russia 56.06°N, 160.64°E; summit elev. 4,835 m On 19 December, KVERT reported that the Level of Concern Color Code <http://www.avo.alaska.edu/avo4/updates/color_code.html> for Kliuchevskoi was raised from Green to Yellow due to a slight increase in seismicity above background levels. Moderate fumarolic activity was noted from the crater. A thermal anomaly in the crater was detected on satellite imagery on 14, 15, and 18 December. 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 have occurred during the past 3,000 years, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation. 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 eruptions from flank craters. Source: Kamchatkan Volcanic Eruption Response Team http://www.kscnet.ru/ivs/kvert/updates.shtml Kliuchevskoi Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1000-26= SHIVELUCH Kamchatka Peninsula, Russia 56.653°N, 161.360°E; summit elev. 3,283 m According to observations and video data, KVERT reported that ash plumes from Shiveluch rose to 4 km (13,100 ft) a.s.l. and drifted NW and ESE on 8 and 12 December, respectively. Based on satellite imagery, ash plumes rose to altitudes of 6-7.5 km (19,700-24,600 ft) a.s.l. and drifted E and NE during 8- 15 December. Seismic activity was generally at background levels. The Tokyo VAAC and KVERT reported that ash plumes rose to altitudes of 7.6-10 km (25,000- 32,800 ft) a.s.l. and drifted E and NW on 16 and 17 December. 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 horseshoe-shaped 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. During the 1990s, intermittent explosive eruptions took place 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 http://www.kscnet.ru/ivs/kvert/updates.shtml, Tokyo Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html Shiveluch Information from the Global Volcanism Program http://www.volcano.si.edu/gvp/world/volcano.cfm?vnum=1000-27= SOPUTAN Sulawesi, Indonesia 1.11°N, 124.73°E; summit elev. 1,784 m According to CVGHM, seismic signals from rockfalls increased at Soputan during 11-13 December. On 14 December, ash clouds rose to an altitude of 2 km (6,600 ft) a.s.l. and ash fell within a 15 km radius of the peak. The emissions were accompanied by thunderous noises that were heard 8 km from the peak. On 15 December the Alert Level was raised from 2 to 3 (on a scale of 1-4) due to this increase in activity. Geologic Summary. The small conical volcano of Soputan on the southern rim of the Quaternary Tondano caldera is one of Sulawesi's most active volcanoes. During historical time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924. Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM) http://portal.vsi.esdm.go.id/joomla/ Soputan Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0606-03= Ongoing Activity BULUSAN Luzon, Philippines 12.770°N, 124.05°E; summit elev. 1,565 m According to new articles, Bulusan emitted ash that was accompanied by rumbling noises and lightning flashes on 20 December. Clouds hindered a view of the summit. Ash deposits up to 4 mm thick were noted in several villages at the foothills. 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: Associated Press http://www.iht.com/articles/ap/2006/12/20/asia/AS_GEN_Philippines_Volcano.php Bulusan Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0703-01= COLIMA Western México 19.514°N, 103.62°W; summit elev. 3,850 m Based on satellite imagery, the Washington VAAC reported that continuous ash- and-steam emissions from Colima produced a plume that drifted SE and W on 15 December. Geologic Summary. The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward- younging volcanoes, Nevado de Colima (the 4,320 m high point of the complex) on the N and the historically active Volcán de Colima on the S. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5- km-wide caldera, breached to the S, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth. Source: Washington Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/messages.html Colima Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1401-04= ETNA Sicily, Italy 37.73°N, 15.00°E; summit elev. 3,315 m Based on increased volcanic tremor, INGV reported that weak Strombolian activity and emissions of lava and ash from the SE Crater of Etna occurred on 6 December. Later that day, seismicity dropped and explosive activity stopped. On 11 December, INGV monitoring cameras recorded Strombolian activity that resumed from a pit on the SE Crater, following a weak increase of seismicity. Lava was emitted continuously from the E flank of the SE Crater since 13 October. Lava also flowed from a vent at 2800 m elevation on the W headwall of the Valle del Bove. The eruption and lava flows from the 2800-m vent finished on 15 December. The Toulouse VAAC reported that a diffuse plume possibly containing ash was intermittently visible from a webcam on 13 December, drifting E. 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. Sources: Sonia Calvari, Istituto Nazionale di Geofisica e Vulcanologia Sezione di Catania http://www.ct.ingv.it/, Toulouse Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/OTH/FR/messages.html Etna Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0101-06= HOME REEF Tonga Islands, Tonga 18.992°S, 174.775°W; summit elev. -2 m Observers from a Royal New Zealand Airforce aircraft reported venting and a sulphur smell from Home Reef on 8 December. The island was about 450 m in diameter, circular in shape, and rose to a height of 73 m (240 ft) a.s.l. The water around the island was cloudy with sediment. Geologic Summary. Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid- 19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, copious amounts of floating pumice, and an ephemeral island 500 x 1500 m wide, with cliffs 30-50 m high that enclosed a water-filled crater. Source: New Zealand GeoNet Project http://www.geonet.org.nz/ Home Reef Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0403-08= KARYMSKY Kamchatka Peninsula, Russia 54.05°N, 159.43°E; summit elev. 1,536 m Seismic data from Karymsky were not available during 8-15 December. Ash plumes were observed drifting in all directions during the reporting period. A thermal anomaly in the crater was detected on satellite imagery during 8-12 December. Pilots reported that an ash plume rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted E on 17 December. Based on satellite data, the Tokyo VAAC reported that an ash plume rose to an altitude of 8.2 km (27,000 ft) a.s.l. and drifted E. The Level of Concern Color Code remained at Orange <http://www.avo.alaska.edu/color_codes.php>. 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. Sources: Kamchatkan Volcanic Eruption Response Team http://www.kscnet.ru/ivs/kvert/updates.shtml, Tokyo Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html Karymsky Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1000-13= KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m During 13-19 December, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae'apuki and East Ka'ili'ili entries. Incandescence on the pali was visible during the reporting period. Rare surface activity on the flow field was observed on 13 December. Incandescence was intermittently visible from the East Pond and January vents, South Wall complex, and Drainhole vent in Pu'u 'O'o's crater. Tremor near Pu`u `O`o continued at moderate levels. According to a news article, a three-year-long inflationary trend of Kilauea?s summit and E and SW rift zones ceased in early October. Since the current on- going eruption began in 1983, a total of three such events have occurred. 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 by lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. The latest Kilauea eruption began in January 1983 along the E rift zone. This long-term ongoing eruption from Pu`u `O`o-Kupaianaha has produced lava flows that have traveled 11-12 km from the vents to the sea, paving broad areas on the S flank of Kilauea and adding new land beyond the former coastline. Sources: US Geological Survey Hawaiian Volcano Observatory http://volcano.wr.usgs.gov/hvostatus.php, Honolulu Advertiser http://the.honoluluadvertiser.com/article/2006/Dec/18/ln/FP612180341.html Kilauea information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1302-01- MANAM offshore New Guinea, Papua New Guinea 4.10°S, 145.06°E; summit elev. 1,807 m Based on satellite imagery, the Darwin VAAC reported that diffuse plumes from Manam drifted mainly W during 13-15 December. Geologic Summary. The 10-km-wide island of Manam is one of Papua New Guinea's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1,807-m-high 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. Five satellitic centers are located near the island's shoreline. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during the past century into the SE avalanche valley. Frequent historical eruptions have been recorded since 1616. Source: Darwin Volcanic Ash Advisory Centre http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html Manam Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0501-02= PITON DE LA FOURNAISE Réunion Island, Indian Ocean 21.23°S, 55.71°E; summit elev. 2,631 m OVPDLF reported that the eruption of Piton de la Fournaise that began on 30 August continued during 13-19 December. Lava flows covered the entire Dolomieu crater floor to a thickness of 10-30 m and spilled over the E rim of the crater, producing flows 100-200 m in length. A lava tube formed from a 27 November overflow of the Dolomieu crater drained lava on the E flank that traveled 2.5 km, S of crater Jean. Geologic Summary. The 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 Dolomieu, a 400-m-high lava shield that has grown within the youngest of three large calderas. This latter caldera 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. Source: Thomas Staudacher, Observatoire Volcanologique du Piton de la Fournaise (OVPDLF) http://ovpf.univ-reunion.fr/, via the Volcano Listserv http://www.volcano.si.edu/reports/volclist/index.htm Piton de la Fournaise Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0303-02= POPOCATÉPETL México 19.02°N, 98.62°W; summit elev. 5,426 m Based on information from the Mexico City MWO and satellite imagery, the Washington VAAC reported that an ash plume from Popocatépetl rose to an altitude of 6.7 km (22,000 ft) a.s.l. on 18 December. 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: Washington Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/messages.html Popocatépetl Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1401-09= RABAUL New Britain Island, Papua New Guinea 4.271°S, 152.203°E; summit elev. 688 m Based on satellite imagery, the Darwin VAAC reported that diffuse plumes from Rabaul drifted mainly N and E during 15-17 December. Geologic Summary. The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the E, where its floor is flooded by Blanche Bay. Two major Holocene caldera-forming eruptions at Rabaul took place as recently as 3,500 and 1,400 years ago. Three small stratovolcanoes lie outside the northern and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and western caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city. Source: Darwin Volcanic Ash Advisory Centre http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html Rabaul Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=0502-14= SAKURA-JIMA Kyushu, Japan 31.58°N, 130.67°E; summit elev. 1,117 m Based on information from JMA, the Tokyo VAAC reported an explosion from Sakura- jima on 13 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. Source: Tokyo Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/OTH/JP/messages.html Sakura-jima Information from the Global Volcanism Program http://www.volcano.si.edu/gvp/world/volcano.cfm?vnum=0802-08= SOUFRIÈRE HILLS Montserrat, West Indies 16.72°N, 62.18°W; summit elev. 1,052 m During 8-15 December, moderate lava-dome growth at Soufrière Hills continued and was focused on the SW part of the dome. Most of the dome surface in a sector from the S to the NW was below 100ºC based on thermal images and moisture along with sulfur deposits accumulated along the SE edge. The dome overtopped the NE crater wall and fresh rock and boulder deposits were observed in that region. 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 east, was formed during an eruption about 4000 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 http://www.mvo.ms/ Soufrière Hills Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1600-05= ST. HELENS Washington, USA 46.20°N, 122.18°W; summit elev. 2,549 m Data from deformation-monitoring instruments showed that during 13-19 December the lava dome at Mount St. Helens continued to grow. Seismicity continued at low levels, punctuated by M 1.5-2.5 and occasionally larger earthquakes. Observations were hindered due to inclement weather during most of the reporting period, but on 18 December, a steam plume rose several hundred meters above the rim and was visible from the Portland area, about 80 km away. Geologic Summary. Prior to 1980, Mount St. Helens formed a conical, youthful volcano sometimes known as the Fuji-san of America. During the 1980 eruption the upper 400 m of the summit was removed by slope failure, leaving a 2 x 3.5 km horseshoe-shaped crater now partially filled by a lava dome. Mount St. Helens was formed during nine eruptive periods beginning about 40-50,000 years ago, and has been the most active volcano in the Cascade Range during the Holocene. The modern edifice was constructed during the last 2,200 years, when the volcano produced basaltic as well as andesitic and dacitic products from summit and flank vents. Historical eruptions in the 19th century originated from the Goat Rocks area on the N flank, and were witnessed by early settlers. Sources: US Geological Survey Cascades Volcano Observatory http://vulcan.wr.usgs.gov/Volcanoes/MSH/CurrentActivity/framework.html, Associated Press http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20061219/mt_st_helens_061219 /20061219?hub=SciTech St. Helens Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1201-05- TUNGURAHUA Ecuador 1.47°S, 78.44°W; summit elev. 5,023 m IG reported that during 13-19 December seismic activity from Tungurahua was minimal in intensity and duration. Steam plumes with possible light-ash content reached an altitude of 8 km (26,000 ft) a.s.l. on 13 December and between 5.8-6 km (19,000-19,700 ft) a.s.l. during 14-17 and 19 December. The plumes drifted in multiple directions. On 14 December, a lahar traveled SW down the Mapayacu gorge. 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 been restricted to 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. Sources: Instituto Geofísico-Escuela Poltécnica Nacional http://www.igepn.edu.ec/, Washington Volcanic Ash Advisory Center http://www.ssd.noaa.gov/VAAC/messages.html Tungurahua Information from the Global Volcanism Program http://www.volcano.si.edu/world/volcano.cfm?vnum=1502-08= +++++++++++++++++++++++++++++++++++++ Sally Kuhn Sennert Global Volcanism Program Smithsonian Institution National Museum of Natural History MRC-119 Department of Mineral Sciences Washington, D.C., 20560 http://www.volcano.si.edu/reports/usgs/index.cfm Phone: 202.633.1805 Fax: 202.357.2476 ++++++++++++++++++++++++++++++++++++++++++ ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
