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SI/USGS Weekly Volcanic Activity Report 9-15 June 2010
From: Sally Kuhn Sennert kuhns@xxxxxx
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SI/USGS Weekly Volcanic Activity Report
9-15 June 2010
Sally Kuhn Sennert - Weekly Report Editor
kuhns@xxxxxx
URL: http://www.volcano.si.edu/reports/usgs/
New Activity/Unrest: | Bezymianny, Central Kamchatka (Russia) | Cleveland, Chuginadak Island | Melimoyu, Southern Chile | Pacaya, Guatemala | San Cristóbal, Nicaragua | Sarigan, Mariana Islands (Central Pacific) | Tiatia, Kunashir Island | Tungurahua, Ecuador | Ulawun, New Britain
Ongoing Activity: | Bagana, Bougainville | Batu Tara, Komba Island (Indonesia) | Dukono, Halmahera | Eyjafjallajökull, Southern Iceland | Fuego, Guatemala | Gaua, Banks Islands (SW Pacific) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kliuchevskoi, Central Kamchatka (Russia) | Popocatépetl, México | Sakura-jima, Kyushu | 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
BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit elev. 2882 m
KVERT reported that although clouds prevented views of Bezymianny during 4-11 June, thermal anomalies were seen in satellite imagery during 4-5 and 8 June. 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) http://www.kscnet.ru/ivs/kvert/index_eng.php
CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m
AVO reported that on 11 June the Volcano Alert Level and the Aviation Color Code for Cleveland was lowered to Unassigned; no activity or unrest was detected during 4-11 June.
Geologic Summary. Symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited dumbbell-shaped Chuginadak Island in the east-central Aleutians. The 1,730-m-high stratovolcano is the highest of the Islands of Four Mountains group and is one of the most active in the Aleutians. Numerous large lava flows descend its flanks. It is possible that some 18th to 19th century eruptions attributed to Carlisle (a volcano located across the Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions from Mt. Cleveland have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.
Source: Alaska Volcano Observatory (AVO) http://www.avo.alaska.edu/
MELIMOYU Southern Chile 44.08°S, 72.88°W; summit elev. 2400 m
ODVAS-SERNAGEOMIN reported on 8 June that the Alert Level for Melimoyu was raised to Green Level 2 due to increased seismicity during May, specifically starting with nine long-period earthquakes on 27 May. The next day six long-period earthquakes preceded two separate seismic swarms. The first swarm was located 2-12 km beneath the summit. Earthquakes in the second swarm were located 7-14 km S of the summit at depths no greater than 15 km. All earthquakes were M 2.5 or less.
Geologic Summary. Melimoyu is a stratovolcano with an 8-km-wide, largely buried caldera located about 40 km NW of the town of Puyuhuapi. The ice-filled caldera is drained by a glacier through a notch in the NE caldera rim. The basaltic-andesite volcano is elongated 10 km in an E-W direction and has several cinder cones. A 1-km-wide crater is located at the summit of the volcano. Two late-Holocene tephra layers have been documented from Melimoyu.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/
PACAYA Guatemala 14.381°N, 90.601°W; summit elev. 2552 m
INSIVUMEH reported that during 9-10 June Pacaya's MacKenney cone emitted white-and-blue fumarolic plumes that rose 300 m high, and generated sounds audible up to 5 km away that resembled airplane engines. Occasional ash plumes drifted 2 km NW. Lava flows continued to be active on the SE flank and moved at a speed of about 1 m per hour. Explosions continued from a lateral crater.
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) http://www.insivumeh.gob.gt/
SAN CRISTOBAL Nicaragua 12.702°N, 87.004°W; summit elev. 1745 m
Based on analyses of satellite imagery, the Washington VAAC reported that on 9 June a well-defined ash plume from San Cristóbal drifted about 115 km WNW.
Geologic Summary. The San Cristóbal volcanic complex, consisting of five principal volcanic edifices, forms the NW end of the Marrabios Range. The symmetrical 1,745-m-high youngest cone, San Cristóbal itself (also known as El Viejo), is Nicaragua's highest volcano and is capped by a 500 x 600 m wide crater. El Chonco, with several flank lava domes, is located 4 km to the west of San Cristóbal; it and the eroded Moyotepe volcano, 4 km to the NE of San Cristóbal, are of Pleistocene age. Volcán Casita contains an elongated summit crater and lies immediately E of San Cristóbal; Casita was the site of a catastrophic landslide and lahar in 1998. The Plio-Pleistocene La Pelona caldera is located at the eastern end of the San Cristóbal complex. Historical eruptions from San Cristóbal, consisting of small-to-moderate explosive activity, have been reported since the 16th century. Some other 16th-century eruptions attributed to Casita volcano are uncertain and may pertain to other Marrabios Range volcanoes.
Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html
SARIGAN Mariana Islands (Central Pacific) 16.708°N, 145.78°E; summit elev. 538 m
On 10 June the Volcano Alert Level and the Aviation Color Code for Sarigan was lowered to Unassigned because no further volcanic activity was noted since the submarine eruption from a vent S of the island on 29 May.
Geologic Summary. Sarigan volcano forms a 3-km-long, roughly triangular island. A low truncated cone with a 750-m-wide summit crater contains a small ash cone. The youngest eruptions produced two lava domes from vents above and near the S crater rim. Lava flows from each dome reached the coast and extended out to sea, forming irregular shorelines. The northern flow overtopped the crater rim on the N and NW sides. The sparse vegetation on the flows indicates they are of Holocene age.
Source: Emergency Management Office of the Commonwealth of the Mariana Islands and the US Geological Survey Hawaiian Volcano Observatory http://volcanoes.usgs.gov/
TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m
SVERT reported that a thermal anomaly from Tiatia was detected by satellite on 10 June. Tiatia does not have a seismic network; satellite image observations are the primary tool for monitoring many of the Kurile Islands volcanoes.
Geologic Summary. Tiatia volcano, one of the most impressive of the Kuril Islands, consists of a beautifully symmetrical cone that rises above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies the NE tip of Kunashir Island and morphologically resembles Mount Vesuvius. The pristine-looking conical central cone, mostly formed by basaltic to basaltic-andesite strombolian eruptions, rises 400 m above the floor of the caldera and contains a 400 x 250 m wide crater with two explosion vents separated by a linear septum. Fresh lava flows cover much of the SW caldera floor and have overflowed the rim, extending to the foot of the older somma, which formed during the late Pleistocene or early Holocene. A lava flow from a flank cone on the northern caldera rim reached the Sea of Okhotsk. A major explosive eruption in 1973 was the first since Tiatia's initial historical eruption in 1812.
Source: Sakhalin Volcanic Eruption Response Team (SVERT) http://www.imgg.ru/rus/labs_vulcan_hazard.php
TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m
Although storm clouds occasionally prevented observations of Tungurahua's summit area during 9-12 June, steam-and-ash plumes were seen and rose to altitudes of 5.5-8 km (18,000-29,500 ft) a.s.l. Daily reports of ashfall came from multiple areas within about 8 km NW, W, and SW, but ash was noted as far away as 22 km NW and 25 km W on 9 June. Blocks, including some that were incandescent, occasionally ejected by explosions rolled at most 1 km down the flanks. Explosions caused noises resembling "cannon shots" and vibrating windows almost daily. During 13-14 June steam plumes from the crater and the NW flank rose 500-1,000 m above the crater and drifted W. An explosion on 15 June generated an ash plume that rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted W.
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/
ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m
RVO reported that during 9-16 June white and gray plumes from Ulawun rose 800-900 m high. Fine ashfall was reported almost daily and affected the NW, W, and SW flanks. During 9-12 June occasional rumbling noises were reported. Fluctuating incandescence from the crater was seen at night on 9 and 10 June from observers in areas to the SW and for a brief period of time on 13 June from areas N.
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)
Ongoing Activity
BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m
Based on analyses of satellite imagery, the Darwin VAAC reported that ash plumes from Bagana rose to an altitude of 3 km (10,000 ft) a.s.l. during 13-14 June and drifted 75-205 km SW and W.
Geologic Summary. Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia's youngest and most active volcanoes. Bagana is a massive symmetrical lava cone largely constructed by an accumulation of viscous andesitic lava flows. The entire lava cone could have been constructed in about 300 years at its present rate of lava production. Eruptive activity at Bagana is characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although explosive activity occasionally producing pyroclastic flows also occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with prominent levees that descend the volcano's flanks on all sides.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev. 748 m
Based on analyses of satellite imagery, the Darwin VAAC reported that during 9 and 11-15 June ash plumes from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 35-65 km W and NW.
Geologic Summary. The small isolated island of Batu Tara in the Flores Sea about 50 km north of Lembata (formerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks of Batu Tara to within 50 m of the 748-m-high summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption from Batu Tara, during 1847-52, produced explosions and a lava flow.
Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/AU/messages.html
DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m
The Darwin VAAC reported that during 9-10 June an ash plume from Dukono was seen in satellite imagery drifting 130 km W.
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
EYJAFJALLAJOKULL Southern Iceland 63.63°N, 19.62°W; summit elev. 1666 m
The Nordic Volcanological Center (NVC) at the Institute of Earth Sciences reported that on 9 June rumbling noises were heard at Gígjökull just before a steam cloud rose from the summit crater. The crater area was not visible the next day, but a few small shallow earthquakes beneath the summit crater continued to be detected. On 11 June white steam was mainly confined to the crater, but occasionally a steam plume rose higher than the rim. Heavy rainfall during the previous few days led to flooding along the Svadbaelisa River. The water contained a large amount of mud and flowed over levees into fields. NVC also noted that a lake about 300 m in diameter had formed in the large summit crater. Steam rose as high as 1 km from the rims, especially from the N side. Two small vents above the water level on the W side emitted brown-colored clouds.
Geologic Summary. Eyjafjallajökull (also known as Eyjafjöll) is located west of Katla volcano. Eyjafjallajökull consists of an E-W-trending, elongated ice-covered basaltic-andesite stratovolcano with a 2.5-km-wide summit caldera. Fissure-fed lava flows occur on both the eastern and western flanks of the volcano, but are more prominent on the western side. Although the 1666-m-high volcano has erupted during historical time, it has been less active than other volcanoes of Iceland's eastern volcanic zone, and relatively few Holocene lava flows are known. An intrusion beneath the south flank from July-December 1999 was accompanied by increased seismic activity and was constrained by tilt measurements, GPS-geodesy and InSAR. The last historical eruption of Eyjafjallajökull prior to an eruption in 2010 produced intermediate-to-silicic tephra from the central caldera during December 1821 to January 1823.
Source: Institute of Earth Sciences http://www.earthice.hi.is/
FUEGO Guatemala 14.473°N, 90.880°W; summit elev. 3763 m
INSIVUMEH reported that during 10-11 June multiple explosions from Fuego produced ash plumes that rose to altitudes of 4.1-4.3 km (13,500-14,100 ft) a.s.l. and drifted NW. Rumbling and "degassing" sounds were associated with the explosions. Occasionally incandescent material was ejected as high as 75 m above the crater and avalanches descended the flanks. Fine ashfall was reported in Sangre de Cristo, 10 km WSW. During a period of increased activity on 11 June, shock waves were detected as far away as 5 km.
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.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/
GAUA Banks Islands (SW Pacific) 14.27°S, 167.50°E; summit elev. 797 m
Based on information from the Vanuatu Geohazards Observatory, the Wellington VAAC reported that on 7 June an ash plume from Gaua rose to an altitude of 3 km (10,000 ft) a.s.l.
Geologic Summary. The roughly 20-km-diameter Gaua Island, also known as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with an 6 x 9 km wide summit caldera. Small parasitic vents near the caldera rim fed Pleistocene lava flows that reached the coast on several sides of the island; several littoral cones were formed where these lava flows reached the sea. Quiet collapse that formed the roughly 700-m-deep caldera was followed by extensive ash eruptions. Construction of the historically active cone of Mount Garat (Gharat) and other small cinder cones in the SW part of the caldera has left a crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat cone is topped by three pit craters. The onset of eruptive activity from a vent high on the SE flank of Mount Garat in 1962 ended a long period of dormancy.
Source: Wellington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/OTH/NZ/messages.html
KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported that during 4-11 June seismic activity from Karymsky was above background levels, and suggested that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. on 6 June. Satellite imagery revealed a thermal anomaly over the volcano during 4-5 and 8 June. Based on information from KVERT and Yelizovo Airport (UHPP), and analyses of satellite imagery, the Tokyo VAAC reported that on 11 June an eruption produced an ash plume that rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted NE and SE. 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) http://www.kscnet.ru/ivs/kvert/index_eng.php
KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m
During 9-15 June HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface remained mostly stable in the deep pit inset within the floor of Halema'uma'u crater; glow from the vent was visible. A plume from the vent mainly drifted SW, dropping small amounts of tephra downwind. Vigorous bubbling of the lava surface was seen during 14-15 June.
At the east rift zone, lava flows that broke out of the TEB lava-tube system at 580 m elevation built up rootless shields. Minor surface lava flows from the shields were often active on the pali and the coastal plain, and advanced along the W side of the TEB flow field towards the abandoned Royal Gardens subdivision. The Pu'u 'O'o web camera recorded a growing and sometimes circulating lava pond on the crater floor that was an estimated 300 x 125 m in dimension. The pond was fed predominantly from a source near the N rim of the Pu'u 'O'o, with some contributions from a source near the S shore.
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 4-11 June seismic activity from Kliuchevskoi was above background levels and Strombolian activity was seen. Gas-and-steam plumes, occasionally containing a small amount of ash, were also noted. On 5 June ash plumes rose to an altitude of 7.3 km (24,000 ft) a.s.l. Satellite imagery revealed a large daily thermal anomaly from the volcano, and ash plumes that drifted 60-190 km NE on 5 and 8 June. 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) 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 9-11 June steam-and-gas emissions from Popocatépetl occasionally contained small amounts of ash. On 10 June an ash-and-steam plume rose 800 m above the crater. The next day an ash-and-gas plume rose 1 km above the crater. Later that day, another ash-and-gas plume rose 600 m.
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
Based on information from JMA, the Tokyo VAAC reported explosions from Sakura-jima during 12-14 June. Details of possible resulting plumes were not reported. On 15 June an ash plume at an altitude of 3 km (10,000 ft) a.s.l. was reported by a pilot.
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 during 4-11 June seismic activity from Shiveluch was above background levels and hot avalanches were seen at night. The seismic data suggested that possible ash plumes rose to an altitude of 4.1 km (13,400 ft) a.s.l. during 3-4 and 6 June. Ash plumes were seen during 4-6 and 9 June rising to an altitude of 4.5 km (14,800 ft) a.s.l. Satellite imagery showed a large daily thermal anomaly over the lava dome, and ash plumes that drifted 100 km SE on 4 June. The Aviation Color Code level 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
SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m
MVO reported that rockfalls and pyroclastic flows from the Soufrière Hills lava dome occurred during 4-11 June. The largest pyroclastic flow originated in the collapse scar and traveled 1 km N. 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) http://www.mvo.ms/
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