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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.

http://www.volcano.si.edu/reports/usgs/index.cfm

7-13 September 2005
New Activity:

 Ebeko, Russia
 Veniaminof, USA

Ongoing Activity:
 Anatahan, Mariana Islands
 Colima, México
 Cotopaxi, Ecuador
 Fuego, Guatemala
 Karymsky, Russia
 Kilauea, USA
 Nyiragongo, D.R. of the Congo
 Pacaya, Guatemala
 Santa Ana, El Salvador
 Santa María, Guatemala
 Shiveluch, Russia
 Soufrière Hills, Montserrat
 St. Helens, USA
 Tungurahua, Ecuador

28 September- 4 October 2005

New Activity: | Erta Ale, Ethiopia | Santa Ana, El Salvador

ERTA ALE Ethiopia; 13.60°N, 40.67°E; summit elev. 613 m

A group of scientists assessed the visible changes at Erta Ale on 26 September after activity began around 24 September. In comparison to observations made in November 2004, they found that the southern main crater/pit had widened significantly, with portions of the previous crater walls having collapsed into the lava lake. A new cone-shaped construct had grown within the southern main crater where there had been a platform. A lava lake occupied the entire width of the inner crater/pit. In the northern crater/pit, there was a solidified lava bulge and abundant "smoking" along the crater walls. No incandescent lava was visible in the pit.

Based on descriptions by local residents of seeing "red and glowing light shooting and rising into the air above the volcano," the scientists believe that a Strombolian eruption probably occurred, emitting a significant volume of fresh magma within, and possibly out of, the pit. According to news reports, about 50,000 nomads in Ethiopia's Afar region were displaced after the eruption.

Background. Erta Ale is an isolated basaltic shield volcano that is the most active volcano in Ethiopia. The broad, 50-km-wide volcano rises more than 600 m from below sea level in the barren Danakil depression. Erta Ale is the namesake and most prominent feature of the Erta Ale Range. The 613-m-high volcano contains a 0.7 x 1.6 km, elliptical summit crater housing steep-sided pit craters. Another larger 1.8 x 3.1 km wide depression elongated parallel to the trend of the Erta Ale range is located to the SE of the summit and is bounded by curvilinear fault scarps on the SE side. Fresh-looking basaltic lava flows from these fissures have poured into the caldera and locally overflowed its rim. The summit caldera is renowned for one, or sometimes two long-term lava lakes that have been active since at least 1967, or possibly since 1906.

Sources: Gezahegn Yirgu, Department of Earth Sciences, Addis Ababa University, Agence France-Presse

Erta Ale Information from the Global Volcanism Program

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SANTA ANA El Salvador 13.853°N, 89.630°W; summit elev. 2,365 m; All times are local (= UTC - 6 hours)

SNET reported that a sudden eruption at Santa Ana (also called Ilamatepec) on 1 October around 0820 produced an ash-and-gas plume to a height of ~10 km above the volcano (or 40,600 ft a.s.l.). According to the Washington VAAC, ash was visible on satellite imagery at a height of ~14 km (46,000 ft) a.s.l. Ash fell in towns W of the volcano, including in Naranjos, Nahuizalco, Juayúa, Ahuachapán, and La Hachadura. Volcanic blocks up to a meter in diameter fell as far as 2 km S of the volcano's crater. Lahar deposits were seen SE of the volcano. The Alert Level within a 4-km radius around the volcano's central crater was raised to Red, the highest level. According to news reports, two people were killed by landslides (possibly caused by heavy rain in the area) in the town of Palo Campana, and thousands of residents near the volcano were evacuated. As many as 1,400 hectares of crops were damaged by ash.

Prior to the eruption, significant changes in seismicity were not noted. On 3 October, after the eruption, seismicity fluctuated and small explosions occasionally occurred. Earthquakes associated with explosions were recorded. In addition, there was a decrease in the amount of sulfur dioxide emitted from the volcano. SNET noted that eruptive activity could continue at the volcano.

Background. Santa Ana, El Salvador's highest volcano, is a massive stratovolcano immediately W of Coatepeque caldera. Collapse of the volcano during the late Pleistocene or early Holocene produced a massive debris avalanche that swept into the Pacific, forming the Acajutla Peninsula. Reconstruction of the volcano rapidly filled the collapse scarp. The broad summit of the volcano is cut by several crescentic craters, and a series of parasitic vents and cones have formed along a 20-km-long fissure system that extends from near the town of Chalchuapa NNW of the volcano to the San Marcelino and Cerro Chino cinder cones on the SE flank. Historical activity, largely consisting of small-to-moderate explosive eruptions from both summit and flank vents, has been documented since the 16th century. The San Marcelino cinder cone on the SE flank produced a lava flow in 1722 that traveled 11 km to the E.

Sources: Servicio Nacional de Estudios Territoriales (SNET), Reuters, Associated Press, ReliefWeb

Santa Ana Information from the Global Volcanism Program

Ongoing Activity: | Barren Island, Andaman Islands | Cayambe, Ecuador | Colima, México | Dukono, Indonesia | Kilauea, USA | Manam, Papua New Guinea | Reventador, Ecuador | Shiveluch, Russia | Soufrière Hills, Montserrat | St. Helens, USA | Tungurahua, Ecuador | Veniaminof, USA

=========== Ongoing Activity (Week of 28 September- 4 October 2005) =====================

BARREN ISLAND Andaman Islands, Indian Ocean, India 12.29°N, 93.88°E; summit elev. 354 m

Low-level plumes from Barren Island were visible on satellite imagery on 28 September and 2 October. The current eruption of Barren Island began on 28 May 2005.

Background. Barren Island, a possession of India in the Andaman Sea about 135 km NE of Port Blair in the Andaman Islands, is the only historically active volcano along the N-S-trending volcanic arc extending between Sumatra and Burma (Myanmar). The 354-m-high island is the emergent summit of volcano that rises from a depth of about 2,250 m. The small, uninhabited 3-km-wide island contains a roughly 2-km-wide caldera with walls 250-350 m high. The caldera, which is open to the sea on the W, was created during a major explosive eruption in the late Pleistocene that produced pyroclastic-flow and -surge deposits. The morphology of a fresh pyroclastic cone that was constructed in the center of the caldera has varied during the course of historical eruptions. Lava flows fill much of the caldera floor and have reached the sea along the western coast during eruptions in the 19th century and more recently in 1991 and 1995.

Source: Darwin Volcanic Ash Advisory Center

Barren Island Information from the Global Volcanism Program

CAYAMBE Ecuador 0.029°N, 77.986°W; summit elev. 5,790 m

A cluster of earthquakes that had been recorded at Cayambe since 16 September, with about 300 small earthquakes occurring during 16-18 September, decreased in number significantly after 19 September. During 19-25 September, an average of 5.3 earthquakes occurred daily.

Background. The massive compound Cayambe stratovolcano is located on the isolated western edge of the Cordillera Real. The 5,790-m-high volcano, whose southern flank lies astride the equator, is capped by glaciers, which descend down to 4,200 m on the eastern Amazonian side. The modern Nevado Cayambe volcano, constructed to the E of an older volcanic complex, contains two summit lava domes located about 1.5 km apart, the western of which is the highest. Several other lava domes on the upper flanks have been the source of pyroclastic flows that reached the lower flanks of the volcano. A prominent Holocene pyroclastic cone on the lower eastern flank fed thick lava flows that traveled about 10 km to the E. Nevado Cayambe was recently discovered to have produced frequent explosive eruptions during the Holocene, and to have had a single historical eruption, during 1785-86.

Source: Instituto Geofísico-Escuela Politécnica Nacional

Cayambe Information from the Global Volcanism Program

COLIMA western México 19.514°N,103.62°W; summit elev. ~3,850 m; All times are local (= UTC - 5 hours)

During 28 September to 3 October, several small explosions occurred at Colima. Based on information from the Mexico City MWO, the Washington VAAC reported that a plume was emitted on 28 September that rose to a height of ~6.1 km (20,000 ft) a.s.l. and drifted NNW.

Background. 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.

Sources: Universidad de Colima, Washington Volcanic Ash Advisory Center

Colima Information from the Global Volcanism Program

DUKONO Halmahera, Indonesia 1.70°N, 127.87°E; summit elev. 1,185 m

A thin low-level plume from Dukono was visible on satellite imagery on 28 September extending NE.

Background. 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 since 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 Center

Dukono Information from the Global Volcanism Program

KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m

During 28 September- 2 October, lava from Kilauea continued to enter the sea at the East Lae`apuki area, and surface lava flows were visible on the Pulama Pali fault scarp. During the report period, background volcanic tremor was near normal levels at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of inflation and deflation occurred at the volcano during the report period.

Background. 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 about 104 km2 of land on the S flank of Kilauea and building 207 hectares of new land.

Source: US Geological Survey Hawaiian Volcano Observatory

Kilauea Information from the Global Volcanism Program

MANAM offshore New Guinea, Papua New Guinea 4.10°S, 145.06°E; summit elev. 1,807 m

On 1 October, a pilot observed ash from Manam below a height of ~3 km (10,000 ft) a.s.l. extending NW. Ash was not visible on satellite imagery.

Background. 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.

Sources: Darwin Volcanic Ash Advisory Center

Manam Information from the Global Volcanism Program

REVENTADOR Ecuador 0.078°S, 77.656°W, summit elev. 3,562 m

During 19-25 September, several small explosions occurred at Reventador. An explosion on 20 September produced an ash plume to a height of ~5.8 m (19,000 ft) a.s.l. Small amounts of ash fell in the towns of El Chaco, San Francisco de Borja, and Baeza. During the report week, there was a reduction in the number of earthquakes at the volcano.

Background. 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 Geofisico-Escuela Poltecnica Nacional

Reventador Information from the Global Volcanism Program

SHIVELUCH Kamchatka Peninsula, Russia 56.653°N, 161.360°E; summit elev. 3,283 m

Growth of Shiveluch's lava dome and heightened seismicity continued at the volcano during 23-30 September. Weak gas-and-steam plumes, thermal anomalies at the lava dome, and new pyroclastic-flow deposits, were noted during the report week. Shiveluch remained at Concern Color Code Orange.

Background. 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.

Source: Kamchatkan Volcanic Eruption Response Team

Shiveluch Information from the Global Volcanism Program

SOUFRIÈRE HILLS Montserrat, West Indies 16.72°N, 62.18°W; summit elev. 1,052 m

Volcanic and seismic activity at Soufrière Hills remained at elevated levels during 23-30 September. Slow lava-dome growth continued at the volcano. The daily sulfur-dioxide flux averaged 950 metric tons per day (t/d), above the long-term eruption average of 500 t/d.

Background. 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

Soufrière Hills Information from the Global Volcanism Program

ST. HELENS Washington, USA 46.20°N, 122.18°W; summit elev. 2,549 m

Growth of the new lava dome inside the crater of Mount St. Helens continued during 28 September to 4 October, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. There were no significant changes in seismicity or deformation during the report period and the level of eruptive activity remained similar to previous weeks. Reanalysis of late September time-series photographs of the active part of the new lava dome indicated that points on the dome moved northwestward and upward at about 5.5 meters per day as extrusion continued. St Helens remained at Volcano Advisory (Alert Level 2); aviation color code Orange.

Background. 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.

Source: US Geological Survey Cascades Volcano Observatory

St. Helens Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.47°S, 78.44°W; summit elev. 5,023 m

During 28 September to 3 October, volcanic activity at Tungurahua remained at low levels with small emissions of steam, gas, and variable ash content. A pilot reported an ash plume on 29 September at a height of ~6.1 km (20,000 ft) a.s.l.

Background. 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 initially prompted temporary evacuation of the entire town of Baños on the N side of the volcano.

Source: Instituto Geofisico-Escuela Politécnica Nacional

Tungurahua Information from the Global Volcanism Program

VENIAMINOF Alaska Peninsula, USA 56.17°N, 159.38°W; summit elev. 2,507 m

AVO decreased the Concern Color Code at Veniaminof from Yellow to Green (the lowest level) on 28 September after seismicity at the volcano had been at background levels for over a week and there was no evidence to suggest that minor ash explosions were continuing.

Background. Massive Veniaminof volcano, one of the highest and largest volcanoes on the Alaska Peninsula, is truncated by a steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700 years ago. The caldera rim is up to 520 m high on the N, is deeply notched on the W by Cone Glacier, and is covered by an ice sheet on the S. Post-caldera vents are located along a NW-SE zone bisecting the caldera that extends 55 km from near the Bering Sea coast, across the caldera, and down the Pacific flank. Historical eruptions probably all originated from the westernmost and most prominent of two intra-caldera cones, which reaches an elevation of 2,156 m and rises about 300 m above the surrounding icefield. The other cone is larger, and has a summit crater or caldera that may reach 2.5 km in diameter, but is more subdued and barely rises above the glacier surface.

Source: Alaska Volcano Observatory

Veniaminof Information from the Global Volcanism Program


Institutions studying volcanoes are located in Ecuador, Indonesia, Japan, New Zealand, United States and Russia

Contact: Gari Mayberry - Weekly Report Editor
URL: http://www.volcano.si.edu/reports/usgs/

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Global Volcanism Program — Department of Mineral Sciences — National Museum of Natural History — Smithsonian Institution

Partial list of volcanoes around the world.

http://vulcan.wr.usgs.gov/Volcanoes/framework.html

Eruptions at Tavurvur Cone in Rabaul - During May 2005 and 4 years ago in April 2001.
http://www.volcano.si.edu/world/volcano.cfm?vnum=0502-14=&volpage=var#bgvn_3007

Also - activity in Monowai Seamount (75 km (45 miles) ENE of Rotorua, New Zealand) have been accompanied by swarm of earthquakes and activity along the Kermadec Trench. 
http://www.volcano.si.edu/world/volcano.cfm?vnum=0402-05-&volpage=var

See the thread on Earthquakes - http://www.everything-science.com/index.php?option=com_smf&Itemid=82&topic=5244.msg57873#msg57873.

Barren Island in the region of the big 9.0 Mag earthquake of Dec 26, 2006.

http://www.volcano.si.edu/world/volcano.cfm?vnum=0600-01=&volpage=var#bgvn_3007

Heavy monsoon rains that fell soon after the beginning of the eruption on 28 May made observations and fieldwork difficult, and the eruption appeared to have ended by 6 July.

On 13 June an Indian Navy ship transported Geological Survey of India scientists Sumit Kr. Mitra, P.C. Bandopadhyay, Sanjeev Raghav, and Tapan Pal to the island. Prior to the visit the volcano was spewing a gray ash plume charged with water vapor from both the main crater and a subsidiary vent on the SW slope. Around 13 June activity at the subsidiary vent decreased considerably and lava debris formed a mound of loose hot fragments. Forceful ejection of bombs and lapilli continued from the main crater. The proximal accumulations of pyroclasts displayed some incandescence. Red-hot lava fragments were forcefully ejecting from the main crater to heights of more than 100 m, accompanied by loud explosions. Strombolian fire fountains every 15-30 seconds created an eruption column and mushroom-shaped plume that blew to the N. Hand specimen study revealed both jet-black and brownish black basaltic fragments. Both types contained large phenocrysts of plagioclase and pyroxene in a finer black groundmass with a porphyritic texture.

Current volcano activity on the current date - images require Google Earth or Keyhole application.

http://volcano.und.edu/vwdocs/current_volcs/current.html

GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4,276 m

Heightened seismic activity continued at Galeras during 16-22 November. According to news articles, only ~1,000 of the ~9,000 residents who were ordered to evacuate had left as of 18 November.

Galeras, a stratovolcano (http://volcanoes.usgs.gov/Products/Pglossary/stratovolcano.html) with a large breached caldera (http://volcanoes.usgs.gov/Products/Pglossary/caldera.html) located immediately W of the city of Pasto, is one of Colombia's most frequently active volcanoes. The dominantly andesitic Galeras volcanic complex has been active for more than 1 million years, and two major caldera collapse eruptions took place during the late Pleistocene (http://vulcan.wr.usgs.gov/Glossary/geo_time_scale.html). Long-term extensive hydrothermal alteration has affected the volcano. This has contributed to large-scale edifice collapse that has occurred on at least three occasions, producing debris avalanches that swept to the W and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. Major explosive eruptions since the mid Holocene (http://vulcan.wr.usgs.gov/Glossary/geo_time_scale.html) have produced widespread tephra (http://volcanoes.usgs.gov/Products/Pglossary/tephra.html) deposits and pyroclastic flows (http://volcanoes.usgs.gov/Products/Pglossary/PyroFlow.html) that swept all but the southern flanks. A central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate historical eruptions since the time of the Spanish conquistadors.

Colombia Volcano Erupts, Spews Ash on City (http://news.yahoo.com/s/ap/20051124/ap_on_re_la_am_ca/colombia_volcano;_ylt=ApnwM39wWhMjeCsqgxO3yIi3IxIF;_ylu=X3oDMTBjMHVqMTQ4BHNlYwN5bnN1YmNhdA--)

BOGOTA, Colombia - A volcano erupted Thursday in southwestern Colombia, spewing smoke and ash, and raising fears for the safety of nearby villagers, officials said.

Police and emergency officials were on high alert after the 14,110-foot Galeras volcano became active at dawn and dumped heaps of ash on the city of Pasto, 12 miles away.

"It was a brief eruption of ash for 30 minutes that was not preceded by a temblor inside the volcano," said Marta Lucia Calvache of Colombia's Volcanology Institute. "But there is still a thin plume of ash leaving the crater, and we can't rule out the possibility of further eruptions."

The government this month ordered the preventive evacuation of thousands of people living in the shadow of the volcano amid signs of an imminent eruption. But many farmers are believed to have defied the order and stayed behind, fearful of losing their livelihoods by leaving crops unattended.

Calvache urged any families who remain in a wide area surrounding the volcano to leave immediately and seek medical treatment if they have trouble breathing.

"A lot of ash has fallen. We are scooping it up and putting it into plastic bags. There is a strong smell of sulfur in the air," said Yolanda Casas, a Pasto resident wearing protective goggles and a face mask.

Schools and many offices in Pasto were closed for the day.

The Galeras has a long history of activity, fraying nerves in Pasto. More than 100 minor tremors were felt in the city during the volcano's last major eruption, in April 2002, although no damage or injury was reported.

A 1993 eruption killed nine people, including five scientists from around the globe who had descended into the crater to sample gases at the moment it blew.

Submitted 1400 November 21, 2005 HST (1000 November 22, 2005 local Anatahan time)

For the week ending November 21, Anatahan has not produced significant amounts of ash.

Seismicity over the past week has been at background levels amounting to a few percent of the late June 2005 maximum. Small long-period earthquakes occur sparsely.

One regional earthquake event was reported by NEIC. The earthquake magnitude 5.8 occurred 2005 November 15 23:01:14 UTC. This event has been located 160 miles N of Uracas. Two other magnitude 4+ events were recorded ~ 260 miles NNW of Uracas in the Volcano Islands.

Microseismicity has returned to the Sarigan area. Conservatively 35 events have been counted with the maximum number events in a 24-hour period of 16 microearthquakes occurring on November 16, 2005. On average the other days had 2 to 5 events.

http://hvo.wr.usgs.gov/cnmi/index.html
This is interesting because it mentions that the first historical eruption of Anatahan Volcano began suddenly on the evening of May 10, 2003.  So does this mean anything, especially in conjunction with the seismic activity on the Ring of Fire, and the Australian and Asian regions?

I think people along coasts in N. Pacific Nations must think about tsunami.

This is a really cool place, but potentially dangerous.

Vanuatu Volcano Bursts Into Life

AMBAE ISLAND, Vanuatu (AP) - An erupting volcano on this remote South Pacific island burst into spectacular life Thursday — shooting steam and toxic gases 9,845 feet into the sky.

Huge columns of dense white steam and muddy ash spewed above Ambae Island to reach the greatest height seen since the Mt. Manaro volcano began erupting Nov. 27.

Thousands of villagers have been evacuated from the path of a possible lahar, or mud flow, that vulcanologists fear could burst over the crater lip if the eruption continues or intensifies, sweeping away the flimsy homes in its path.

A "red zone" has been declared around the volcano and several ships were ready to evacuate islanders if the situation worsens dramatically.

New Zealand vulcanologist Brad Scott, who is on Ambae monitoring the eruption, said "it remains a low-level eruption, but it could go either way — worsen or slowly subside."

The plumes of steam and gases were bursting from a huge vent in the middle of a muddy gray-brown Lake Vui in the crater — which before the eruptions began last month was a picturesque calm aqua blue.

Pilot Charles Nelson of local charter company Flight Club Vila said the lake "is looking like a huge grubby bowl of hot kava," referring to a murky local drink made of the pounded roots of a local pepper plant mixed with water.

Nelson was speaking after flying close to the erupting volcano Thursday morning.

Dead trees ring the edge of the crater, while trees in dense jungle nearby were covered in ash that has been belching from the volcano.

The huge smoke, ash and gas plume cast a shadow over now deserted villages clinging to the volcano's flank.

Some 5,000 villagers — half the island's population — are squatting in townships in low-lying areas of the northwest and southeast corners of the small island, one of more than 80 in the archipelago, which is studded with active and dormant volcanoes. The islands, with a total population of 200,000 people, are 1,400 miles northeast of Sydney, Australia.

"We're worried but it's still not increasing its activity and remains on level 2," or yellow alert, local transport operator Simean Tali said.

The ships mean "we should get off (the island) if it goes up," he added.

Two hospitals on the island have been emptied of patients, and teams of doctors and nurses were on call to fly to Ambae from the capital, Port Vila, if a major eruption occurs, the National Disaster Management Office said.

"Maybe nothing is going to happen, but it is better to be ready than not," the Daily Post newspaper quoted Prime Minister Ham Lini as saying.

Ambae, an hour's flight northeast from Port Vila, lies near the islands of Pentecost and Maewo, which could be used to help resettle people displaced by a major eruption.

09/2005 (BGVN 30:09) September 2005 satellite image and infrared data portray ongoing eruption
http://www.volcano.si.edu/world/volcano.cfm?vnum=1900-081&VErupt=Y&VSources=Y&VRep=Y&VWeekly=Y&volpage=var#bgvn_3009

The first recorded eruption of Mt. Belinda volcano (Montagu Island), which began around 20 October 2001, continued (as reported in BGVN 28:02, 29:01, 29:09, 29:10) until at least the latter part of 2005. Information for the following report was prepared and submitted by Matt Patrick of the Hawai'i Institute of Geophysics and Planetology (HIGP) and John Smelie of the British Antarctic Survey, with the assistance of the HIGP Thermal Alerts Team.

This eruption was detected by the MODVOLC automated satellite detection system, which scans for anomalous thermal activity in MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data over the entire Earth approximately twice per day (Wright and others, 2004). Investigators acquired a recent, 23 Sept 2005, cloud-free ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) image (15-30 m pixel size), which provided valuable information on a new phase of activity. It revealed a larger effusive eruption than previously identified in satellite imagery of Montagu Island (figure).

Gunung Merapi (7.54 S, 110.44 E) is a tall (2968 m, 9,794 ft or 1.7 miles high) volcano and has steep slopes. The top of the mountain has no vegetation because erupted ash often falls there.

Dense vegetation covers the flanks of the volcano. The soil is very rich because of the volcanic ash, the surrounding soil makes it attractive for farmers to live near the volcano.

Small eruptions happen every 2-3 years, bigger ones every 10-15 years, and very large ones every 50-60 years. The biggest eruptions occurred in the years 1006, 1786, 1822, 1872 and 1930. The eruption of 1006 covered the central part of the island of Java with ash. The destruction was so bad that the existing Hindu kingdom was destroyed and the island was taken over by Muslims.

It is a stratovolcano located in central Java. It is 45 miles north of Yogyakarta. The latest eruption was on Monday, July 20th 1998. It forced 2,100 people to flee the area. At first a huge column of black ash towered above the island. The lava flowed down the flanks of the volcano, destroying many acers of plantations to the west and southwest. Last of all came the mudslides due to the rain over the fresh debris.

Mount Merapi's fatal eruption was in November of 1994. Hot lava, heat clouds and volcanic ash killed sixty people. Since then many acres of land are closed. It also erupted on July 13, 1998. Lava flooded and ash reached two miles upward into the sky.

Yogyakarta has a population of 500,000. The current eruption began in 1987. Because of the rich, fresh, new, soil the mountain is an ideal area for wildlife, plants and plantations. After most eruptions some of the people must rebuild and recreate their area.

BBC News - Merapi Eruption Feb 2001 - http://news.bbc.co.uk/1/hi/world/asia-pacific/1163376.stm

John Seach's page on Merapi - http://www.volcanolive.com/merapi.html
Seach puts Merapi's summit at 2911 m.

Note there is another volcano, Marapi, on Sumatra.

WELLINGTON, New Zealand (AP) - A young conservation worker who was checking a volcano's crater lake when it unexpectedly burst to life, spewing mounds of ash and soot, most likely died in the eruption in the remote nature reserve, a conservation official said Saturday.

The eruption in one of Raoul Island's three main craters — the first there since 1964 — threw rocks and boulders into the air and buried the area around the lake in mud and ash up to 16 feet deep.

John Funnel, the helicopter pilot who flew the rescue mission, said the eruption ripped up trees and dumped ash over half the 72-acre island. He said the dense clouds of ash would have brought the helicopter down if he had flown into them.

The volcano spewed steam and ash hundreds of yards into the air on Friday, and moderate earthquakes of magnitude 3 to 4 shook the island, but no lava or molten rock was reported flowing from the vent.

Manam eruption in Papua/New Guinea.

http://volcano.und.nodak.edu/vwdocs/volc_images/southeast_asia/manam.html

http://volcano.und.nodak.edu/vwdocs/current_volcs/manam/manam.html

Recent Activity for MANAM, located offshore New Guinea, Papua New Guinea 4.10°S, 145.06°E; summit elev. 1,807 m

During March 9-11,2006 both summit craters at Manam released gas,and seismicity was at moderate levels. Inspections of deposits from an eruption on 27 February confirmed that pyroclastic flows traveled down the SW and SE valleys and that a lava flow was confined to the upper part of the SW valley. On 7 March, a team from RVO witnessed a pyroclastic flow down the SE valley. Scoria and ashfall affected the E part of the island between Warisi and Bokure. 

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.

See also - http://www.volcanolive.com/manam.html

and

http://www.volcano.si.edu/world/volcano.cfm?vnum=0501-02=

Alaska's Augustine Volcano,  SW Alaska, USA  59.363°N, 153.43°W; summit elev. 1,252 m

Recent activity

Low-level eruptive activity continued at Augustine during March 3-10, 2006. The overall level of seismicity increased, with periods of prolonged volcanic tremor and an increase in the frequency of small volcano-tectonic earthquakes. The seismic network, particularly on the E flank, continued to record block-and-ash-flows, rock avalanches, and rockfalls that originated from the summit lava dome. Vigorous steaming was seen on 9 March, mostly from fumaroles on the S and W sides of the dome.  Observations on 8 and 9 March revealed that small-scale collapses of the summit lava dome occurred regularly, usually producing block-and-ash-flows and small diffuse ash clouds. The block-and-ash-flows occurred on the E to NE sector of the volcano and extended to within ~1 km of the coastline. Airborne measurements of gas emissions on 9 March indicated both SO₂ and CO₂ gas in the plume. This was the first time since the fall of 2005 that CO₂ had been a component of the gas plume, and likely indicated the presence of new magma entering the volcanic system. All available information indicated that the lava dome at the volcano's summit continued to grow. According to AVO, over several days before 10 March the rate of dome growth increased relative to the past several weeks, probably reflecting the influx of new magma. Augustine remained at Concern Color Code (http://www.avo.alaska.edu/color_codes.php) Orange.

Augustine volcano, rising above Kamishak Bay in the southern Cook Inlet about 290 km SW of Anchorage, is the most active volcano of the eastern Aleutian arc. It consists of a complex of overlapping summit lava domes surrounded by an apron of volcaniclastic debris that descends to the sea on all sides. Few lava flows are exposed; the flanks consist mainly of debris-avalanche and pyroclastic-flow deposits formed by repeated collapse and regrowth of the volcano's summit. The latest episode of edifice collapse occurred during Augustine's largest historical eruption in 1883; subsequent dome growth has restored the volcano to a height comparable to that prior to 1883. The oldest dated volcanic rocks on Augustine are more than 40,000 years old. At least 11 large debris avalanches have reached the sea during the past 1800-2000 years, and five major pumiceous tephras have been erupted during this interval.  Historical eruptions have typically consisted of explosive activity with emplacement of pumiceous pyroclastic-flow deposits followed by lava dome extrusion with associated block-and-ash flows.

For more information -
http://www.volcano.si.edu/world/volcano.cfm?vnum=1103-01-

Volcano prompts Peru evacuation

The authorities in Peru have declared a state of emergency around a volcano that has begun spitting ash and smoke after almost 40 years of inactivity.

The Ubinas volcano in southern Peru started erupting three weeks ago, killing livestock and polluting water.

http://news.bbc.co.uk/2/hi/americas/4935568.stm


Some background from 1998 - http://www.igp.gob.pe/volubi.html

View of the Ubinas volcano in Moquegua, some 1000 km south of Lima. Gas and cinder ejected by Ubinas volcano in southern Peru drove 200 persons from their homes and threatened 7,000 more, many of whom are reluctant to leave, officials said.

  - AFP, Friday, April 21, 2006

Mount Merapi is erupting in Indonesia

Thousands Flee Rumbling Indonesia Volcano (http://news.yahoo.com/s/ap/20060513/ap_on_re_as/indonesia_volcano;_ylt=AsjyVpmws..3A.H7q5v4gPms0NUE;_ylu=X3oDMTA2Z2szazkxBHNlYwN0bQ--)

YOGYAKARTA, Indonesia - Indonesia ordered the immediate evacuation Saturday of thousands of people from the slopes of Mount Merapi volcano, warning of an imminent eruption as the mountain oozed fiery lava and belched clouds of black ash.

Background on Merapi -

http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13538 (http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13538)

Back in April -

Frequent earthquakes and plumes of sulfur-laden gas indicated that Mt. Merapi was gearing up for an eruption in late April 2006. The volcano is one of Indonesia’s most active and dangerous volcanoes. The slopes of the volcano are densely populated, with four districts clustered on its flanks. As many as 80,000 people may be displaced if the volcano erupts, depending on which way the lava flows down the summit, reported the United Nations Office for the Coordination of Humanitarian Affairs (OCHA). Thousands of people who live near the volcano had been evacuated by April 27, and more were preparing to leave as the volcano continued to rumble. An eruption in 1994 claimed at least 66 lives, and a 1930 eruption killed 1,370.

Among the most serious dangers an erupting Merapi poses to the surrounding population are its characteristic pyroclastic flows and lahars. Avalanches of hot ash, gas, and rock sweep down the mountain at speeds of 100 kilometers per hour or more in a pyroclastic flow, accompanied or followed by volcanic mudflows—lahars. Pyroclastic flows and lahars have been responsible for much of the damage caused by the volcano during its long eruptive history.

Merapi (Smithsonian) - http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-25= (http://www.volcano.si.edu/world/volcano.cfm?vnum=0603-25=)

Pictures of Merapi eruption

http://news.yahoo.com/photos/sm/events/sc/080601volcano/p:5

Volcanoes are more or less thermal events, whereas earthquakes are primarily mechanical.

Now in areas like the Cascade mountain range in the US, it is believed that the mechanical energy of the subduction zone does cause tremendous heat - thermal energy - which leads to volcanoes, like Mt St Helens, Mt Hood, Mt Rainier, etc.  And the subduction zone experiences earthquakes.

Merapi and the big earthquke near Yogyakarta are the direct consequence of the interaction between the Australian and Asian techtonic plates.

This map shows the historical seismicity in the section of Indonesia near Yogyakarta -
http://neic.usgs.gov/neis/eq_depot/2006/eq_060526_neb6/neic_neb6_h.html

The orange and yellow colors indicate shallow (and more destructive) earthqukes on the southern coast of Java.  The blue and red indicate very deep earthquakes on the north side of Java.  The Volcanoes in Indonesia are distributed along the southern side of Java and Indonesia.

http://www.volcano.si.edu/world/region.cfm?rnum=06

http://volcano.und.edu/vwdocs/volc_images/img_java1.html

http://www.volcano.si.edu/world/region.cfm?rnum=0603

As a country with 129 active volcanoes spreading across the archipelago, Indonesia has frequently suffered from natural disaster associated with volcanic eruption which happen at least once a year. Due to this volcanic risk, geographical and meteorological, an effective method of monitoring  is required for those volcanoes.

The aim of all the monitoring methods is to reduce the impact of volcanic eruptions by establishing available early warnings, by mapping areas exposed to volcanological hazards, 
and taking timely preventive measures. 

Eighty of 129 volcanoes have been classified into A type according to their recorded-eruptions since 1600. Those are dotted across Sumatera (12 volcanoes), Java (21), Bali (2), Nusatenggara (20), Banda Sea (9), North  Sulawesi (6), Sangihe (5) 
and Halmahera (5).

  http://www.vsi.esdm.go.id/volcanoes/index.htm
http://www.vsi.esdm.go.id/picture/index.html

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New Scientiest, June 1 - The earthquake last weekend on the Indonesian island of Java, which killed thousands and left hundreds of thousands homeless, may be about to trigger a second disaster. The Volcanological Survey of Indonesia says that volcanic activity on nearby Mount Merapi has tripled since the quake.

There is normally thought to be no direct relationship between earthquakes and volcanoes, but it is possible for one to influence the other. "The earthquake epicentre was relatively close to Merapi, only around 50 kilometres away, so it is possible that the seismic activity did something to the magmatic plumbing system," says Brian Baptie, a seismologist at the British Geological Survey. "It is partially due to the kind of volcano it is. The lava dome is easily destabilised, with bits collapsing and forming pyroclastic flows."

  ::)

Lava spewing in the crater of the 2,361 metre (7,746 ft) Mt. Karthala near Moroni, the capital of the Comoros Island, May 29, 2006.



http://www.peakbagger.com/peak.aspx?pid=11322

http://news.yahoo.com/s/ap/20060812/ap_on_sc/philippines_volcano

LEGAZPI, Philippines - President        Gloria Macapagal Arroyo on Saturday visited villagers forced to flee their homes due to restive Mayon volcano and ordered officials to speed up efforts to improve conditions at cramped evacuation centers.

Scientists told Arroyo in a briefing that Mayon, the Philippines' most active volcano, appears to be gearing up for an explosive eruption since it began quietly oozing lava four weeks ago.

Following successive ash explosions on Monday, officials ordered a mass evacuation of villages on the southern and southeastern slopes of the volcano, which are the most vulnerable to a violent eruption.

Some background information -

http://volcano.und.edu/vwdocs/volc_images/southeast_asia/philippines/mayon.html
http://volcano.und.edu/vwdocs/current_volcs/philippines/mayonvol.html

http://vulcan.wr.usgs.gov/Volcanoes/Philippines/description_philippines_volcanoes.html

http://www.aenet.org/volcano/mayon.htm

http://earth.esa.int/ew/planning/pl_mayonvo(philippines)-aug06.htm

Tungurahua (Quichua tunguri (throat), rahua (fire): "Throat of Fire") is an active stratovolcano in Ecuador. It is situated in the Central Cordillera of the Ecuadorian Andes.

On July 14, 2006, Tungurahua started its most violent eruption since 1999. At around 6:00pm, the volcano spewed a 15 km column of ashes, vapor and rocks. The column drifted towards the Pacific Ocean and was clearly visible on satellite photos.

During the night and morning of July 15 constant tremors, explosions, ash emissions and rocks falls, put the population in Pelileo, Baños, Penipe, and other counties of the Provinces of Chimborazo and Tungurahua on alert. It is reported that lava flows damaged the road between Baños and Penipe. The ashes destroyed fields and calcined animals. As of July 17, it was reported that for the first time since 1999, pyroclastic flows had occurred, reaching the evacuated hamlet of Cusua and the Las Juntas bridge.

The activity continued slightly muted for one month, until August 16. On the morning of that day, at around 8:25 am, a huge explosion signaled the start of what appears to be the main event of this eruptive episode. An 8 km lava column arose from the crater. The volcano also spewed enormous quantities of hot rocks and ashes. Overnight, the whole province of Tungurahua, including Ambato, Pelileo, Baños and the province of Chimborazo including Riobamba and Penipe were covered with rocks and ashes. Some 200 sq. km (80 sq. miles) of crops have been destroyed.

http://en.wikipedia.org/wiki/Tungurahua
 
Summit Elevation: 5023 m (16,479 feet)
Latitude: 1.467°S  1°28'1"S
Longitude: 78.442°W 78°26'30"W

Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major volcanic edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II itself collapsed about 3000 years ago and produced a large debris-avalanche deposit and a horseshoe-shaped caldera open to the west, inside which the modern glacier-capped stratovolcano (Tungurahua III) was constructed. 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. Prior to a long-term eruption beginning in 1995 that caused the temporary evacuation of the city of Baños at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925. 

http://www.volcano.si.edu/world/volcano.cfm?vnum=1502-08=

pretty volcano here:

http://www.esa.int/esaEO/SEMNX9C4VUE_index_0.html

Scientific Nature: Researchers Use Volcanic Eruption as Climate Lab (http://www.sciam.com/article.cfm?chanID=sa003&articleID=F4890BEE-E7F2-99DF-3978F15888CDF19C&ref=rss)

Earth's climate cannot be replicated in a lab. So to understand how this critical component of the planet's heat regulation works, scientists must rely on "natural experiments." Such natural experiments take apocalyptic form, such as the eruption of Mount Pinatubo in the Philippines in June 1991 that sent 10 cubic kilometers of ash, gas and other materials sky high. By tracking how this eruption affected the global climate--and determining how to trace its footprint in other records--scientists have turned the catastrophe into a tool for comprehension. "The big problem with climate--and trying to study it--is you can't play with it in the lab," says atmospheric scientist Joanna Futyan of Columbia University. "We were trying to use this abrupt event as a natural experiment: something dramatic happened and you can look at how the atmosphere responds to it."

Solar irradiance data on Mauna Loa indicate a transient cooling effect coincident with certain volcanic eruptions.

http://newsimg.bbc.co.uk/media/images/42627000/jpg/_42627381_stromboli_416_afp.jpg

Volcanic Italian island on alert
http://news.bbc.co.uk/2/hi/europe/6401701.stm

Emergency plans have been put into operation after two new craters opened on the summit of the volcanic Italian island of Stromboli.

One of the new lava streams created on the island, just north of Sicily, has already started flowing into the sea.

Coastguard patrol boats have been deployed and the population of 750 people has been urged to stay away from the danger areas.

The last major eruption in 2002 caused a collapse that led to a small tsunami.

The wave reached 10 metres (33ft) high and caused serious damage to Stromboli village on the north of the island.

Watch out!

Some amazing pictures.

http://volcano.und.edu/vwintl/vwintl.html

Perhaps the most famous volcano - Krakatoa or Krakatau Krakatao

http://en.wikipedia.org/wiki/Krakatoa