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Shammu
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« Reply #255 on: March 21, 2009, 11:29:19 PM »

KLIUCHEVSKOI

As of the 20th of March, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that moderate fumarolic activity of the volcano continues. Gas-steam and/or aerosolic with ash plumes from the volcano could affect low-flying aircraft. Seismic activity was above background levels on March 15-18 and at background levels on March 12-14. According to visual data, a weak and moderate fumarolic activity was observed at the volcano on March 12-13 and 17-18. According to satellite data, a weak thermal anomaly was registered over the volcano on March 12-13 and 16-18.

Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. Kliuchevskoi rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred at Kliuchevskoi during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 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 numerous major explosive and effusive eruptions from flank craters.

The Current Colour Code for Kliuchevskoi is YELLOW .
~~~~~~~~~~~~~

KORYAKSKY

As of the 20th of March, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that activity of the volcano continues. Aerosolic plumes containing ash continues to observing at the volcano. The activity of the volcano could affect low-flying aircraft. Seismic activity of the volcano was above background levels on March 13th and at background levels during other days of the week. Aerosolic plumes containing small amount of ash raising up to 4.0 km (13,200 ft) ASL and extending to the eastern directions from the volcano were observed all week. According to the data by volcanologists, ash continues to come from the upper fumarolic vent, small amount of ash covers all volcanic slopes. New not great a well on the snow was noted in central part of the summit crater of the volcano. According to satellite data, aerosolic plumes containing ash extended >140 km (87 mi) mainly to the eastern directions from the volcano all week.

The large symmetrical Koryaksky stratovolcano is the most prominent landmark of the NW-trending Avachinskaya volcano group, which towers above Kamchatka's largest city, Petropavlovsk. Erosion has produced a ribbed surface on the eastern flanks of the 3456-m-high volcano; the youngest lava flows are found on the upper western flank and below SE-flank cinder cones. No strong explosive eruptions have been documented during the Holocene. Extensive Holocene lava fields on the western flank were primarily fed by summit vents; those on the SW flank originated from flank vents. Lahars associated with a period of lava effusion from south- and SW-flank fissure vents about 3900-3500 years ago reached Avacha Bay. Only a few moderate explosive eruptions have occurred during historical time. Koryaksky's first historical eruption, in 1895, also produced a lava flow.

The Current Colour Code for Koryaksky is ORANGE .
~~~~~~~~~~~~~

Mt. EREBUS

As of the 1st of March, the Mt. Erebus Volcano Observatory (MEVO) reported that Antarctica's Mt. Erebus continues with a molten lava lake and vapour emissions. It may be covered with glaciers, but they do little to cool the volcano's molten core. The world's southernmost volcano to show activity during recorded history, Erebus holds a lava lake and occasionally experiences explosive eruptions. In 2004, the reliable presence of a lava lake at this volcano's summit made Mt. Erebus the perfect place to test a self-directed satellite and sensor.

The above image shows two views of Mt. Erebus from February 6, 2009, captured by sensors on NASA's Earth Observing-1 (EO-1) satellite. The larger image was acquired by the Advanced Land Imager (ALI), and the inset image was acquired by the Hyperion sensor. The larger image shows a true-colour, photo-like view of the volcano, and the inset image shows thermal activity, highlighting the volcano's molten lava lake.

On May 7, 2004, the Autonomous Sciencecraft Experiment on EO-1 first demonstrated its ability to detect volcanic activity by sensing thermal emissions at Erebus. After the initial detection, the satellite gave itself new orders to take fresh observations of the volcano several hours later. Scientists who subsequently examined the data EO-1 acquired confirmed that a genuine thermal emission had been detected. Since that time, EO-1 has been successfully employed to detect other volcanic eruptions, including those near densely populated areas.

The Mt. Erebus image shows a fairly typical level of activity for the volcano, including a molten lava lake and vapour emissions. Erebus is a stratovolcano composed of alternating layers of solidified ash, hardened lava, and rocks ejected by earlier eruptions. The volcano was erupting when British explorer Captain James Ross first observed it 1841, and it has shown continuous lava lake activity since 1972.

Mt. Erebus, the world's southernmost historically active volcano, overlooks the McMurdo research station on Ross Island. The 3794-m-high Erebus is the largest of three major volcanoes forming the crudely triangular Ross Island. The summit of the dominantly phonolitic Mount Erebus has been modified by one or two generations of caldera formation. A summit plateau at about 3200-m altitude marks the rim of the youngest caldera, which formed during the late-Pleistocene and within which the modern cone was constructed. An elliptical 500 x 600 m wide, 110-m-deep crater truncates the summit and contains an active lava lake within a 250-m-wide, 100-m-deep inner crater. The glacier-covered volcano was erupting when first sighted by Captain James Ross in 1841. Continuous lava-lake activity with minor explosions, punctuated by occasional larger Strombolian explosions that eject bombs onto the crater rim, has been documented since 1972, but has probably been occurring for much of the volcano's recent history.

The Current Colour Code for Mt. Erebus is ORANGE .
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« Reply #256 on: March 21, 2009, 11:32:22 PM »

Mt. ETNA

As of the 14th of March, the INGV-CT reported that since two days on March 10, a resumption of the explosive activity s' is produced on the " boutonnière" located at 2800 metres of altitude under the Southern crater East. This new explosive activity is accompanied by an increase in the flow by lava flow which flows in Valle del Bove.

Mt. 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 of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km horseshoe-shaped caldera open to the east. Two styles of eruptive activity typically occur at Mt. 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 (the latter formed in 1978). Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank.

The Current Colour Code for Mt. Etna is ORANGE .
~~~~~~~~~~~~~~

PACAYA

As of the 21st of March, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that for Atmospheric conditions: Partial strom cloud, Winds to the North-Northeast to 26 Km/h; pluvial precipitation: 0.0 mm Activity: White and blue fumaroles of low height were observed that moved to the South of the volcano. 2 rivers of lava are observed the Southwest in a lapse of 25 and 50 m.

The eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlán caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1100 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. A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19th century. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the cone.

The Current Colour Code for Pacaya is ORANGE .
~~~~~~~~~~

PITON de la FOURNAISE

As of the 8th of February, the Institut de Physique du Globe de Paris via the Observatoire Volcanologique du Piton de la Fournaise (OVPDLF) has reported that the eruption from Piton de la Fournaise that began on the 14th of December 2008 has terminated. In spite of the bad weather which generates much noise on the seismic signals, the recordings do not show any more any sign of eruptive activity in the Dolomieu crater since 0000 hrs local, (2000 hrs UTC). The eruption which began on December 14th at 2300 (UTC) is finished on February 4th at 2000 (UTC).

The massive Piton de la Fournaise basaltic shield volcano on the French island of Réunion in the western Indian Ocean is one of the world's most active volcanoes. Much of its >530,000 year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three calderas formed at about 250,000, 65,000, and less than 5000 years ago by progressive eastward slumping of the volcano. Numerous pyroclastic cones dot the floor of the calderas and their outer flanks. Most historical eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest caldera, which is 8 km wide and breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures on the outer flanks of the caldera. The Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris, monitors this very active volcano.

The Current Colour Code for Piton de la Fournaise is ORANGE .
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« Reply #257 on: March 21, 2009, 11:34:36 PM »

POAS

As of the 15th of February, the Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI-UNA) reported that fieldwork was carried out on Feb. 11, 2009 to assess and document impact of rockslides within and around Poás Volcano active crater. Hundreds of rockslides (all sizes) were drawn and explained in a field report, one month after the Cinchona earthquake shook the summit and surroundings. Previously unstable areas (subject to gravity) were the most affected 360 degrees around the intracrater area. Many other rockslides occurred along walls supposedly stable.

Although no augmented activity is related to massive falling of material, eventually fine sediments will end up at the bottom of the hot, acidic lake. A previous unstable area, east and near the lake, fell almost completely, burying a fumarolic axis that acted as a subaerial release for some 9 years. It seems that the vigorous degassing activity returned entirely to the dome and the hot lake. Hence the lake shows heavy curtains of gas and vapour. Fumarolic activity from the dome looks stronger and sustained, compared to recent years.

On the 17th of January last, the Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI-UNA) reported that a small phreatic eruption happened the 12th of January at 1411 hrs (20 is reported in the volcano Bridles: 11 GMT). The event can be described like an eruption phreatic small with dimensions of 50 metres of diameter by 15 metres of height that happened in centre of the lagoon of the active crater. It was observed at the beginning of the eruption as a black colour rose to the water column loaded with the sediments of the bottom of the lagoon taking, at the same time the sound was heard that produced the exit of the column later and the fall of the water and sediments in the lake of the crater. Later the column of gases of white colour was only observed that took to the wind and the surge to it in the lagoon associated to the eruption. In the seismic station of the volcano Bridles the signal associated to this event is registered. This eruption was observed from the edge This of the crater by the geologist Jorge Brenes, civil servant of the OVSICORI-UNA, altogether with the volcanist Dr. Hazel Rymer, of the Open University, England; the Dr. Corine A. Locke and the Dr. John Cassidy of the University of Auckland, New Zealand. Also from the viewpoint of visitors of the volcano Bridles this eruption was observed partially by some police officers. Preliminarily a photo of the event appears that serves like reference for the general information. This small eruption like a gas bubble can be interpreted that was released suddenly from the fractured hydrothermal system. By the recent seismicity in the zone near the volcano, a constant monitoring of its activity stays.

The broad, well-vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano, which is one of Costa Rica's most prominent natural landmarks, are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the 2708-m-high complex stratovolcano extends to the lower northern flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, is cold and clear and last erupted about 7500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since the first historical eruption was reported in 1828. Poás eruptions often include geyser-like ejections of crater-lake water.

The Current Colour Code for Poas is ORANGE.
~~~~~~~~~~~~

POPOCATEPETL

As of the 21st of March, CENAPRED has reported that in the last 24 hours the monitoring system again detected 5 low intensity exhalations acompanied by steam, gas and sometimes small ammounts of ash. Also a high frequency tremor signal was detected during about 40 minutes. The other monitored parameters remain without important changes. At the moment of this report CENAPRED can see the volcano with a steam and gas emissions. From high to low probability the expected activity scenarios in the next hours, days or weeks are: moderate exhalations, some with ash emissions; occasionally mild incandescence during nights and sporadic low level explosions with low probabilities of incandescent fragment at short distance to the crater. There is a permanent monitoring of the volcano to detect any change. The traffic light of volcanic alert remains in YELLOW Phase 2.

Volcano Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5426 m 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 250-450 m deep crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas south of the volcano. The modern volcano was constructed to the south of the late-Pleistocene to Holocene El Fraile cone. Three major plinian eruptions, the most recent of which took place about 800 AD, have occurred from Popocatépetl since the mid Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since pre-columbian time.

The Current Colour Code for Popocatepetl is YELLOW.
~~~~~~~~~~~~

RABAUL

As of the 19th of March, the Global Volcanism Network (GVN) has reported that during 9-15 March gray ash plumes from Rabaul caldera's Tavurvur cone rose to a maximum altitude of 2.7 km (8,900 ft) a.s.l. Incandescence was seen at night and incandescent tephra was occasionally ejected from the crater during periods of heightened activity. Light ashfall was reported in areas to the NW and SE.

the low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbour. 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.

The Current Colour Code for Rabaul is ORANGE .
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« Reply #258 on: March 21, 2009, 11:36:28 PM »

SAKURA-JIMA

As of the 19th of March, the Japanese Meteorlogical Agency (JMA) has reported that on 14 March, JMA reported two Vulcanian explosions from Sakura-Jima to heights of 400-500 m above an unspecified crater; ejected bombs landed as far away as 800 m. Both the summit crater and Showa crater on the E flank had recently been active. Based on information from JMA, the Tokyo VAAC reported that an eruption on 17 March produced a plume that rose to an altitude of 2.1 km (6,000 ft) a.s.l. and drifted E.

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.

The Current Colour Code for Sakura-Jima is ORANGE .
~~~~~~~~~~

SANGAY

As of the 13th of March, the Global Volcanism Network (GVN) has reported that using both GOES-10 and GOES-12, no volcanic ash or hotspots could be detected in imagery. There have been no pilot reports since this morning.

the isolated Sangay volcano, located E of the Andean crest, is the southernmost of Ecuador's volcanoes, and its most active. It has been in frequent eruption for the past several centuries. The steep-sided, 5,230-m-high glacier-covered volcano grew within horseshoe-shaped calderas of two previous edifices, which were destroyed by collapse to the E, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. Sangay towers above the tropical jungle on the E side; on the other sides flat plains of ash from the volcano have been sculpted by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an historical eruption was in 1628. More or less continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The more or less constant eruptive activity has caused frequent changes to the morphology of the summit crater complex.

The Current Colour Code for Sangay is ORANGE .
~~~~~~~~~

SANTA MARIA

As of the 21st of March, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that for Atmospheric conditions: Partially dimmed; Winds to the North to 4.3Km/h; rains of 5.8 mm appear Activity: Degassing white colour of 100 m of height that dispersed in a Southwestern direction. 1 moderate explosion that elevated material of gray colour clearly forming a column 700 m of height, that dispersed towards and the Southwest, with ash falls in the area of the properties of Mount Claro and La Florida. Activity by avalanches was calm.

The symmetrical, forest-covered Santa María volcano is one of the most prominent of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The 3772-m-high stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1.5-km-wide crater. The oval-shaped crater extends from just below the summit of volcano Santa María to the lower flank and was formed during a catastrophic eruption in 1902. The renowned plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santa Maria has occurred episodically from four westward-younging vents, the most recent of which is Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.

The Current Colour Code for Santa Maria is ORANGE .
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« Reply #259 on: March 21, 2009, 11:39:20 PM »

SEMERU

As of the 19th of March, the Volcanological Society of Indonesia (VSI) reported that based on information from CVGHM, the Darwin VAAC reported that on 12 March an eruption from Semeru produced a plume to an altitude of 4.6 km (15,000 ft) a.s.l. Ash was not identified on satellite imagery.

Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises abruptly to 3676 m above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Semeru has been in almost continuous eruption since 1967.

The Current Colour Code for Semeru is ORANGE ALERT LEVEL 2 .
~~~~~~~~~~~~

SHEVELUCH

As of the 20th of March, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that the lava flow continues to effuse on the eastern flanks of the lava dome. Ash explosions up to 10 km (32,800 ft) ASL could occur at any time. The activity of the volcano could affect international and low-flying aircraft. Seismicity was above background levels all week. According to seismic data, probably ash plumes up to 3.5 km (11,500 ft) ASL occurred at the volcano. According to visual data, strong and moderate fumarolic activity was observed on March 13-14 and 18th. An incandescence of the lava dome was observed by night on March 14th and 18th. Clouds obscured the volcano during the other days of the week. According to satellite data, a thermal anomaly was registered over the lava dome on March 12-14 and 16-19.

The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskoi volcano group. The 1300 cu km Shiveluch is one of Kamchatka's largest and most active volcanic structures. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera.

The Current Colour Code for Sheveluch is ORANGE .
~~~~~~~~~~~~

SOUFRIERE HILLS

As of the 21st of March, the Monstserrat Volcano Observatory (MVO) reported that activity at the Soufrière Hills Volcano has remained at a low level. The sulphur dioxide flux continues to be low. Sulphur dioxide flux was an average of 388 tonnes per day with a minimum of 166 and a maximum of 607. The figures continue to be low compared to the typical values seen over the last few months but one high value was recorded during the latter part of the week.

Seismic activity was low, with five rockfalls and four volcano-tectonic earthquakes during the week. Helicopter observations on the 18th of March provided some good views of the volcano and showed no major changes in the dome or in fumarolic activity. An inspection of the Tar River Valley during the day confirmed that a seismic signal recorded at 4am was a pyroclastic flow that nearly reached the sea. An increase in volcanic activity could occur at any time and with no warning. Lahars are always a potential hazard in river valleys around the volcano during and after periods of heavy rain. The Hazard Level is 3. There is no access to Zone C.

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.

The Current Colour Code for Soufriere Hills is currently at ORANGE ALERT LEVEL 3

Note; The next level is Red for Soufriere Hills
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« Reply #260 on: March 21, 2009, 11:41:16 PM »

STROMBOLI

As of the 1st of March, the Global Volcanism Network (GVN) has reported that Stromboli is remarkable because of the incredible length of time for which it has been in almost continuous eruption and continues in year 2009. For at least the last 2,000 years, the same pattern of eruption has been maintained, in which explosions occur at the summit craters with mild to moderate eruptions of incandescent volcanic bombs at intervals ranging from minutes to hours. This characteristic Strombolian eruption, as it is known, is also observed at other volcanoes worldwide. Eruptions from the summit craters typically result in few second-lasting mild energetic bursts emitting ash, incandescent lava fragments and lithic blocks up to a few hundred meters high. Stromboli's activity is almost exclusively explosive, but lava flows do occasionally occur - an effusive eruption in 2002 was its first in 17 years. The mildly explosive eruptions are also occasionally punctuated by much larger eruptions. The largest eruption of the last hundred years occurred in 1930, and resulted in the deaths of several people and the destruction of a number of houses by flying volcanic bombs. Large eruptions occur at intervals of years to decades, and the most recent large eruption began in 2002, causing the closure of the island to non-residents for several months.

Spectacular incandescent nighttime explosions at Stromboli volcano have long attracted visitors to the "Lighthouse of the Mediterranean." Stromboli, the NE-most of the Aeolian Islands, has lent its name to the frequent mild explosive activity that has characterised its eruptions throughout much of historical time. The small, 924-m-high island of Stromboli is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period from about 13,000 to 5000 years ago was followed by formation of the modern Stromboli edifice. The active summit vents are located at the head of the Sciara del Fuoco, a prominent horseshoe-shaped scarp formed about 5000 years ago as a result of the most recent of a series of slope failures that extend to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild strombolian explosions, sometimes accompanied by lava flows, have been recorded at Stromboli for more than a millennium.

The Current Colour Code for Stromboli is ORANGE .
~~~~~~~~~~~~~~~

SUWANOSE-JIMA

As of the 19th of March, the Global Volcanism Network (GVN) has reported that based on information from JMA, the Tokyo VAAC reported that on 15 and 16 March eruptions from Suwanose-Jima produced plumes that rose to an altitude of 1.5 km (5,000 ft) a.s.l. Plumes drifted E on 15 March.

The 8-km-long, spindle-shaped island of Suwanose-Jima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. Only about 50 persons live on the sparsely populated island. The summit of the volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanose-Jima, one of Japan's most frequently active volcanoes, was in a state of intermittent Strombolian activity from On-take, the NE summit crater, that began in 1949 and lasted nearly a half century. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, after which the island was uninhabited for about 70 years. The SW crater produced lava flows that reached the western coast in 1813, and lava flows reached the eastern coast of the island in 1884.

The Current Colour Code for Suwanose-Jima is ORANGE .
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TUNGURAHUA

As of the 21st of March, the Instituto Geofísico (IG) has reported that activity of the volcano is considered as moderate with tendency to the reduction. volcano presents/displays an activity characterised by episodes of tremor of emission of low energy and few events of long period, do not have reports of ash falls. In spite of present rains by the sector, they have not been generated lahars.

The IG reports that with respect to seismicity: In the last 24 hours, a total of 7 events of long period (LP) and 15 episodes of tremor of emission. Observations, Emissions and Ash: The climatic conditions in the volcano do not have allowed to realise visual observations. One does not have reports gives ash fall. Rains and Lahars: Light rains from the night yesterday of have not generated the formation of lahars, from the sector of Juive reported the increase in the volume of the gorge of the same name.

The official colour of the volcanic alarm light remains on ORANGE .
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« Reply #261 on: March 21, 2009, 11:43:39 PM »

UBINAS

As of the 19th of March, the Global Volcanism Netowrk (GVN) has reported that based on a SIGMET notice and analysis of satellite imagery, the Buenos Aires VAAC reported that during 11-12 March ash plumes from Ubinas rose to altitudes of 5.5-7.3 km (18,000-24,000 ft) a.s.l. and drifted NE. A SIGMET notice described an ash plume that rose to altitudes of 9.1-9.8 km (30,000-32,000 ft) a.s.l. on 15 March; ash was not identified in satellite imagery.

A small, 1.2-km-wide caldera that cuts the top of Ubinas, Peru's most active volcano, gives it a truncated appearance. Ubinas is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front of Peru. The upper slopes of the stratovolcano, composed primarily of Pleistocene andesitic lava flows, steepen to nearly 45 degrees. The steep-walled, 150-m-deep summit caldera contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank of Ubinas extend 10 km from the volcano. Widespread Plinian pumice-fall deposits from Ubinas include some of Holocene age. Holocene lava flows are visible on the volcano's flanks, but historical activity, documented since the 16th century, has consisted of intermittent minor explosive eruptions.

The Current Colour Code for Ubinas is ORANGE .
~~~~~~~~~~~~

YASUR

As of the 1st of March, colleague John Seach of Australia reports that Yasur volcano continues to erupt many times per hour as it has done so for at least 800 years. Yasur has been called the "Lighthouse of the Pacific" because of the regular Strombolian eruptions visible from sea. John conducts expedtions to Yasur as well as many other volcanoes in the area.

Yasur, the best-known and most frequently visited of the Vanuatu volcanoes, has been in more-or-less continuous strombolian and vulcanian activity since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Yasur, located at the SE tip of Tanna Island, is a mostly unvegetated 361-m-high pyroclastic cone with a nearly circular, 400-m-wide summit crater. Yasur is largely contained within the small Yenkahe caldera and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide, horseshoe-shaped caldera associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions of Yasur has raised Port Resolution harbour more than 20 m during the past century.

The Current Colour Code for Yasur is ORANGE .
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« Reply #262 on: March 24, 2009, 12:23:12 AM »

Alaska volcano Mount Redoubt erupts 5 times

By Mary Pemberton, Associated Press Writer
Mon Mar 23, 7:28 pm ET

WILLOW, Alaska – Alaska's Mount Redoubt volcano erupted five times overnight, sending an ash plume more than 9 miles into the air in the volcano's first emissions in nearly 20 years. Residents in the state's largest city were spared from falling ash, though fine gray dust fell Monday morning on small communities north of Anchorage.

"It's coming down," Rita Jackson, 56, said Monday morning at a 24-hour grocery store in Willow, about 50 miles north of Anchorage. She slid her fingers across the hood of her car, through a dusting of ash.

Ash from Alaska's volcanos is like a rock fragment with jagged edges and has been used as an industrial abrasive. It can injure skin, eyes and breathing passages. The young, the elderly and people with respiratory problems are especially susceptible to ash-related health problems. Ash can also cause damage engines in planes, cars and other vehicles.

Alaska Airlines on Monday canceled 19 flights because of the ash. In-state carrier Era Aviation canceled four, and Elmendorf Air Force Base in Anchorage kept 60 planes, including fighter jets, cargo aircraft and a 747 commercial plane, in shelters.

Five of 20 Alaska state senators were scheduled on the morning flight from Anchorage to Juneau, which was canceled. As a result, consideration of a resolution accepting federal stimulus funds was put off until Wednesday.

The first eruption, in a sparsely populated area across Cook Inlet from the Kenai Peninsula, occurred at 10:38 p.m. Sunday and the fifth happened at 4:30 a.m. Monday, according to the Alaska Volcano Observatory.

The wind took the ash cloud away from Anchorage, toward Willow and Talkeetna, near Mount McKinley, North America's largest mountain.

There were reports of a quarter-inch of ash in Trapper Creek and up to a half-inch at a lakeside lodge near Skwentna.

Dave Stricklan, a hydrometeorogical technician with the National Weather Service, expected very fine ash.

"Just kind of a light dusting," he said. He said the significant amount of ash probably dropped immediately, right down the side of the volcano.

"The heavier stuff drops out very quickly, and then the other stuff filters out. There's going to be a very fine amount of it that's going to be suspended in the atmosphere for quite some time," he said. "The finer ash is going to travel farther, and any ash can affect aviation safety."

Jackson said she was taking a sip of coffee when she tasted something funny on her lips — ash. She was experiencing other affects, too.

"My eyes are itching really bad," she said as she hurried to get out of the store and to her car.

Jackson, who unexpectedly got the day off, hurried home from the grocery store to secure a motorcycle, snowmachine and vehicles under protective blue tarps.

The 10,200-foot Redoubt Volcano, roughly 100 miles southwest of Anchorage, last erupted during a four-month period from 1989-90.

In its last eruption, Redoubt sent ash 150 miles away into the path of a KLM jet and its four engines flamed out. The jet dropped more than 2 miles before the crew was able to restart all engines and land safely. The plane required $80 million in repairs.

The volcano became restless earlier this year. The observatory had warned in late January that an eruption could occur at any time.

Increased earthquake activity over the past 48 hours prompted scientists to raise the alert level for Mount Redoubt on Sunday.

On Sunday morning, 40 to 50 earthquakes were being recorded every hour.

A steam plume rising about 1,000 feet above the mountain peak was observed Saturday.

Three seismometers on the mountain were damaged in the eruption but seven others remained in place, said observatory geophysicist John Power.

The observatory planned a helicopter flight to the mountain Monday afternoon to sample ash, repair equipment and monitor flooding along the Drift River, which flows from a glacier of the same name.

Power said the history of past eruptions of Redoubt indicate the volcano could erupt again in the next few days or weeks.

"It's something we need to stay prepared for," he said.

Alaska volcano Mount Redoubt erupts 5 times
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« Reply #263 on: May 12, 2009, 09:52:24 PM »

Scientist says volcanic eruption in Congo imminent
By EDDY ISANGO, Associated Press Writer Eddy Isango, Associated Press Writer Thu May 7, 4:58 pm ET

KINSHASA, Congo – Scientists found evidence of intense volcanic activity — including tremors, pools of lava and plumes of smoke — at two volcanoes near a major city in eastern Congo, and said some residents had fled for fear of an eruption.

The volcanoes in the central African nation could be about to erupt, threatening Goma, which has a population of more than half a million people, scientists said Thursday. They made their observations on visits to the two volcanic peaks of Nyiragongo and Nyamulagira.

"The eruption could be tomorrow, or the day after — or at any other time," said Dieudonne Wafula, the head of Goma's Volcanological Observatory.

The Nyiragongo crater is only 11 miles (18 kilometers) north of Lake Kivu, where Goma is located. Wafula estimates that 1.3 million people are threatened by the two volcanoes, including the residents of Goma, the villages surrounding it and the inhabitants of Gisenyi, located across the Rwandan border.

"The villagers living near Nyiragongo have already left their villages after they saw the volcano shake today. They thought it was already erupting," Wafula said.

He said government agencies and Red Cross workers were making preparations, although the country's infrastructure has been destroyed by decades of civil war.

Nyiragongo is listed as one of the eight most dangerous volcanoes in the world and its lava can flow at up to 24 miles (40 kilometers) per hour, according to Wafula.

The crater last erupted in 2002, destroying about a fifth of the residential areas of Goma, the provincial capital of Congo's North Kivu province. About 100 people died as lava flows as deep as 10 feet (3 meters) overtook parts of the city.

Nyamulagira erupted later the same year, shooting plumes of lava 300 feet (91 meters) into the air, but without threatening Goma.

Scientist says volcanic eruption in Congo imminent
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« Reply #264 on: May 12, 2009, 09:55:22 PM »

AMBRYM

As of the 2nd of April, the Global Volcanism Network (GVN) reported that based on information from the Port Vila airport tower, the Wellington VAAC reported that on 25 March an ash plume from Ambrym rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted about 55 km S. The next day, a pilot reported that "smoke" rose to an altitude of 2.4 km (8,000 ft) a.s.l. Ash was not identified on satellite imagery.

Ambrym, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides arc. A thick, almost exclusively pyroclastic sequence, initially dacitic, then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major plinian eruption with dacitic pyroclastic flows about 1900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the caldera floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations.

The Current Colour Code for Ambrym is ORANGE LEVEL 2 .
~~~~~~~~~~~~~~~~~

ARENAL

As of the 16th of April, the Global Volcanism Network (GVN) reported that during March activity originating from Arenal's Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches from the fronts of lava flows that traveled down the SW flanks. Acid rain and small amounts of ejected pyroclastic material affected the NE and SE flanks. Small avalanches of volcanic material traveled down several ravines. Crater D showed only fumarolic activity.

Conical volcano Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1,657-m-high andesitic volcano towers above the eastern shores of Lake Arenal, which has been enlarged by a hydroelectric project. The earliest known eruptions of Arenal took place about 7,000 years ago. Growth of Arenal has been characterized by periodic major explosive eruptions at several-hundred-year intervals and periods of lava effusion that armor the cone. Arenal's most recent eruptive period began with a major explosive eruption in 1968. Continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows has occurred since then from vents at the summit and on the upper western flank.

The Current Colour Code for Arenal is ORANGE .
~~~~~~~~~~~~~~~~~

ASAMA

As of the 7th of May, the Japan Meteorlogical Agency (JMA) reported that based on information from JMA, the Tokyo VAAC reported that on 30 April and 2 May eruptions from Asama produced plumes that rose to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l. and drifted NE.

Asama, Honshu's most active volcano, overlooks the resort town of Karuizawa, 140 km NW of Tokyo. The volcano is located at the junction of the Izu-Marianas and NE Japan volcanic arcs. The modern cone of Maekake-yama forms the summit of the volcano and is situated east of the horseshoe-shaped remnant of an older andesitic volcano, Kurofu-yama, which was destroyed by a late-Pleistocene landslide about 20,000 years before present (BP). Growth of a dacitic shield volcano was accompanied by pumiceous pyroclastic flows, the largest of which occurred about 14,000-11,000 years BP, and by growth of the Ko-Asama-yama lava dome on the east flank. Maekake-yama, capped by the Kama-yama pyroclastic cone that forms the present summit of the volcano, is probably only a few thousand years old and has an historical record dating back at least to the 11th century AD. Maekake-yama has had several major plinian eruptions, the last two of which occurred in 1108 (Asama's largest Holocene eruption) and 1783 AD.

The Current Colour Code for Asama is YELLOW LEVEL 2
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« Reply #265 on: May 12, 2009, 09:56:31 PM »

BAGANA

As of the 7th of May, the Global Volcanism Netowrk (GVN) has reported that based on analysis of satellite imagery, the Darwin VAAC reported that on 2 and 4 May ash plumes from Bagana rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted 45-55 km NE.

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.

The Current Colour Code for Bagana is ORANGE .
~~~~~~~~~~~~~~~~~~~~

BARREN IS.

As of the 30th of April, the Global Volcanism Netowrk (GVN) has reported that based on analysis of satellite imagery, the Darwin VAAC reported that during 23-25 April ash plumes from Barren Island rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 45-65 km NE, E, and SE.

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 centre 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 historical eruptions.

The Current Colour Code for Barren Is. is ORANGE .
~~~~~~~~~~~~~~~~~~

BATU TARA

As of the 7th of May, the Global Volcanism Netowrk (GVN) has reported that based on analysis of satellite imagery, the Darwin VAAC reported that during 29-30 April and 3-4 May ash plumes from Batu Tara rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted 45-185 km NW and W.

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.

The Current Colour Code for Batu Tara is ORANGE
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« Reply #266 on: May 12, 2009, 09:58:26 PM »

CHAITEN

As of the 10th of May, the Government of Chile (SERNAGEOMIN) has reported that during this period the volcano has been observed during fieldwork carried out on 29 April, and also in partial form during an overflight carried out on 1 May. The eruption continues with the consistent growth of the dome complex and their column of gas and ash, which has occasionally reached 2.0 km above the volcano (see image #1), with gravitational collapses generating block-and-ash flows (FBC; see image # 2). The emission of gas and ash is concentrated principally in the centre of emission located in the south-east sector of the dome complex (image #2). On 1 May there was an overflight of the volcano in a Twin Otter aircraft of FACH (Chilean Air Force), co-ordinated for Mr. Guillermo Nuñez, Director of ONEMI (state emergencies office) for Los Lagos Region. It was possible to observe that the central pinnacle has fractured into three main, very unstable, blocks and that the dome complex has continued with its rapid growth, expanding considerably (see image #3). This produces a major danger for the valley of the Chaitén river, as possible gravitational collapses in the southern sector may generate block-and-ash flows (FBC). The surface morphology of the dome complex is very irregular, with various pinnacles and notable heights (estimated as in the region of 100m).

The seismicity registered by the monitoring network of Chaitén volcano this last week has remained relatively stable with an average of 12 to 14 earthquakes of HB (hybrid) type per day. After the slight decline in magnitudes on 25 and 26 April, there was again an increase after 1 May, nevertheless, the RSAM values have not exceeded 115,000 units and only four events have exceeded 100,000 units. During the last few days there has again occurred a slight decline in the higher magnitudes, the values of which have varied between 3.5 and 4.0, registering a maximum of up to 4.2. With regard to the epicentres of the earthquakes, these have continued to be located on the edges of the caldera, with depths that are principally concentrated between 3 and 13 km.

The eruptive activity continues with the growth of the dome complex, which has risen and expanded. Although the seismic activity occurring to date shows a slight decline in magnitudes, the highest reaching up to magnitude 4.2, the number of HB-type earthquakes has been maintained. In relation to the seismic energy released the levels have been maintained, a phenomenon which is directly related to the growth of the dome complex. In consequence, there is a continuing latent danger of the occurrence of possible explosions and block-and-ash flows (FBC), along with lahars, which may affect valleys adjacent to Chaitén volcano. In consequence, given that the seismic activity remains elevated and, in accordance with this, the sustained growth of the dome complex, with the possibility of the generation of block-and-ash flows (FBC) that may affect the surrounding valleys. Chaiten volcano remains on the highest alert level - RED.

Chaitén is a small, glacier-free caldera with a Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf of Corcovado. A pyroclastic-surge and pumice layer that was considered to originate from the eruption that formed the elliptical 2.5 x 4 km wide summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-high obsidian lava dome occupies much of the caldera floor. Obsidian cobbles from this dome found in the Blanco River are the source of prehistorical artifacts from archaeological sites along the Pacific coast as far as 400 km away from the volcano to the north and south. The caldera is breached on the SW side by a river that drains to the bay of Chaitén, and the high point on its southern rim reaches 1122 m. Two small lakes occupy the caldera floor on the west and north sides of the lava dome.

The Current Colour Code for Chaiten is RED
~~~~~~~~~~~~~~

COLIMA

As of the 12th of May, the Government of the State, through the State Unit of Civil Defence-Colima reported that the equipment of monitoring of the Colima volcano again reported eight exhalations and two fumaroles during last the 72 hours, which has not caused reports on damages or affectation in the adjacent populations, according to information the Government into the State, through the State Unit of Civil Defence Colima. Even though the zone where is the volcano is cleared most of the time, sporadically establishment of clouds, water precipitations appears and electrical activity; for that reason one reminds the population to avoid the permanence in bordering ravines, before the risk of lahars (mud flows). Also, it follows the restriction effective for the overflights that do not have scientific aims or of civil defence, and is prohibited the permanence of people other people's to these activities in ravines of the volcano. According to the monitoring, this past Friday registered a gray exhalation to 640 metres in a vertical direction at 1203 hours, during Saturday three more were reported, at 1124 hours of white colour to 400 metres in a Southwestern direction, at 1356 hours of gray colour to 500 mettrs in a vertical direction and at 1813 hours of white colour to 380 metres in a vertical direction. With respect to the activity of last Sunday one has a report of an exhalation at 0933 hours of white colour to 600 metres in a Southwestern direction, at 0942 hours of white colour to 400 metres in a vertical direction and at 1152 hours of white colour to 500 metres in a vertical direction, also two continuous fumaroles were reported, the first at 1722 hours of white colour to 100 metres in a vertical direction and the second at 1957 hours of white colour to 200 metres in a vertical direction; finally, last Monday was reported an exhalation of gray colour to 500 metres in a vertical direction at 0805 hours.

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 4320 m high point of the complex) on the north and the 3850-m-high historically active Volcán de Colima at the south. A group of cinder cones of late-Pleistocene age is located on the floor of the Colima graben west and east of the Colima complex. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the south, 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.

The Current Colour Code for Colima is ORANGE
~~~~~~~~~~~~~~~~

DEMPO

As of the 26th of March, the Global Volcanism Netowrk (GVN) has reported that on 23 March, CVGHM lowered the Alert Level for Dempo from 2 to 1 (on a scale of 1-4) based on visual observations of the crater lake during 5-6 January and 2-4 March, and decreased seismicity since a phreatic eruption on 1 January. Visitors and residents were advised not to go within a 1-km radius of the summit.

Dempo is a prominent 3173-m-high stratovolcano that rises above the Pasumah Plain of SE Sumatra. Remnants of 7 craters are found at or near the summit, with volcanism migrating to the WNW with time. The historically active summit crater of Gunung Dempo contains a 400-m-wide lake, located at the NW end of the crater complex. Historical eruptions have been restricted to small-to-moderate explosive activity that produced ashfall near the volcano.

The Current Colour Code for Dempo is ORANGE LEVEL 2
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« Reply #267 on: May 12, 2009, 10:00:15 PM »

DIENG

As of the 29th of January, the Pusat Vulkanologi Dan Mitigasi Bencana Geologi (PVDMBG) has reported that the Center of Volcanology and Geological Hazard Mitigation (CVGHM) reported on 22 January that field observations of Dieng's Sibanteng crater revealed that deposits from a 15th of January landslide (of an estimated total volume of 40,000 cubic metres) had covered the vent and triggered a phreatic eruption. The landslide deposits near the vent were covered by tephra from the 15th of January eruption.

The Dieng plateau in the highlands of central Java is renowned both for the variety of its volcanic scenery and as a sacred area housing Java's oldest Hindu temples, dating back to the 9th century AD. The Dieng volcanic complex consists of two or more stratovolcanoes and more than 20 small craters and cones of Pleistocene-to-Holocene age over a 6 x 14 km area. Prahu stratovolcano was truncated by a large Pleistocene caldera, which was subsequently filled by a series of dissected to youthful cones, lava domes, and craters, many containing lakes. Lava flows cover much of the plateau, but have not occurred in historical time, when activity has been restricted to minor phreatic eruptions. Toxic volcanic gas emission has caused fatalities and is a hazard at several craters. The abundant thermal features that dot the plateau and high heat flow make Dieng a major geothermal prospect.

The Current Colour Code for Dieng is ORANGE LEVEL 2
~~~~~~~~~~~~~~~~~~~

DUKONO

As of the 7th of May, the Global Volcanism Network (GVN) has reported that based on analysis of satellite imagery and pilot observations, the Darwin VAAC reported that during 29 April-4 May ash plumes from Dukono rose to an altitude of 3.7-4.5 km (12,000-14,000 ft) a.s.l. and drifted 45-165 km E and NE.

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.

The Current Colour Code for Dukono is ORANGE
~~~~~~~~~~~~~~

EBEKO

As of the 8th of May, the Kamchatkan Volcanic Eruption Response Team (KVERT) has reported that strong gas-steam emission sometimes with ash occur at Ebeko at present. The danger of sudden ash explosions up to 3.5 km (11,500 ft.) ASL exists. Activity of the volcano could affect low-flying aircraft. According to the data by observers from Severo-Kurilsk (Paramushir Island), activity of the volcano continues. Gas-steam plumes containing a small amount of ash were noted on May 2nd. Clouds obscured the volcano in the other days of week. According to satellite monitoring, there were not noted a thermal anomaly over the volcano and ash plumes. Ebeko volcano is not monitored with seismic instruments. KVERT uses satellite monitoring and receives occasional visual observations from Paramushir Island.

The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. The eastern part of the southern crater of Ebeko contains strong solfataras and a large boiling spring. The central crater of Ebeko is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters of Ebeko, on the outer flanks of the cone, and in lateral explosion craters.

The Current Colour Code for Ebeko is YELLOW
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« Reply #268 on: May 12, 2009, 10:02:03 PM »

FERNANDINA

As of the 7th of May, the Instituto Geofísico (IG) has reported that according to a news article, the eruption of Fernandina that began sometime between 2200 on 10 April and 0030 on 11 April continued after about 20 days. Variable activity included steam-and-gas emissions and lava flows.

Fernandina, the most active of Galápagos volcanoes and the one closest to the Galápagos mantle plume, is a basaltic shield volcano with a deep 5 x 6.5 km summit caldera. The volcano displays the classic "overturned soup bowl" profile of Galápagos shield volcanoes. Its caldera is elongated in a NW-SE direction and formed during several episodes of collapse. Circumferential fissures surround the caldera and were instrumental in growth of the volcano. Reporting has been poor in this uninhabited western end of the archipelago, and even a 1981 eruption was not witnessed at the time. In 1968 the caldera floor dropped 350 m following a major explosive eruption. Subsequent eruptions, mostly from vents located on or near the caldera boundary faults, have produced lava flows inside the caldera as well as those in 1995 that reached the coast from a SW-flank vent. Collapse of a nearly 1 cu km section of the east caldera wall during an eruption in 1988 produced a debris-avalanche deposit that covered much of the caldera floor and absorbed the caldera lake.

The Current Colour Code for Fernandina is ORANGE
~~~~~~~~~~~~~~~~~~

FUEGO

As of the 12th of May, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that for Atmospheric conditions: Cleared. Winds to the southeast to 2 km/h. ; Pluvial precipitation: 0.0 mm Activity: The same rank of 30 to 40 explosions per day between weak and moderate stays forming gray ash columns that move to the south, southwest of 4 to 6 km. of the volcanic complex, the explosions generated weak and moderate rumblings, accompanied by avalanches of blocks by different ravines from the volcano.

The volcano 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 3763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta volcano dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta volcano may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango volcano, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. 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 Current Colour Code for Fuego is ORANGE
~~~~~~~~~~~~~~~~

GALERAS

As of the 9th of May, the Instituto Colombiano de Geologia y Mineria (INGEOMINAS) has reported that the predominant seismic activity continues being the associate with the dynamics of flowed to the interior of the volcanic system, that implies as much processes of contribution or also recharges of the magmatic system in surface like gas discharges and ash. The favourable climatic conditions have allowed to observe some of these emissions from different sectors around the volcano, with columns that reached heights of up to 1500 m on the top and with slight dispersion towards the nornoreste by action of winds.

It is emphasised that the Hybrid events that involve processes of fracture of cortical material like of movement of fluids, have shown a low recurrence during the last week. Also, earthquakes have not been registered Tornillo type. Sulphur Dioxide (SO2) measurements, have shown fluctuating values between 300 and 1000 tonnes, considered of low to stop. It is probable that the minimum values of flow are influenced by the low wind speed, that appears at the time of the measurement, and it is demonstrated by the vertical ascent of the gas column, with little dispersion.

In a fly over realised the 6th of May, with the support of the Colombian Air Force, stands out the presence of a crater with a diameter enters 90 100 m, at heart of the main crater, in which incandescence was observed, corresponding to a region of thermal anomaly, with the values near 500°C. In the South and Southwest flank the presence of blocks of great size was detected (between 9 and 13 m of diameter), that corresponded to remante of the 2008 dome and which they were expelled mainly during the eruption of the 24 of April of 2009. The filmic and photographic registries also show, exit of gas from different sectors from the interior of the crater and from their periphery, with mainly white tonality. The recent behaviour of Galeras reflects that the system is presenting/displaying conditions that the partial gas liberation allows, as a result of the effects associated with the recent explosive eruptions and particularly by the presence of an internal crater with incandescent material. The registries of volcanic monitoring continue demonstrating contribution of magmatic material, which makes possible that Galeras continues presenting/displaying fluctuations in the activity levels.

Galeras, a stratovolcano with a large breached caldera located immediately west 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. 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 west and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. Major explosive eruptions since the mid Holocene have produced widespread tephra deposits and pyroclastic flows 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.

The Current Colour Code for Galeras is ORANGE LEVEL 3
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« Reply #269 on: May 12, 2009, 10:04:59 PM »

HUNGA TONGA-HUNGA HA'APAI

As of the 26th of March, as posted by volcanism in Pacific, Tonga has reported that based on information from Tonga Meteorological Services, analysis of satellite imagery, and pilot observations, the Wellington VAAC reported that during 18-19 March ash plumes from Hunga Tonga-Hunga Ha'apai rose to altitudes of 4-5.2 km (13,000-17,000 ft) a.s.l. and drifted NE and about 480 km ENE. On 20 March, steam plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. Wide-spread haze was reported in areas downwind, below an altitude of 1.5 km (5,000 ft) a.s.l., including in Vava'u, a group of islands about 255 km NE of Hunga Tonga-Hunga Ha'apai. On 21 March, an eruption plume rose to an altitude of 0.8 km (2,500 ft) a.s.l.

According to news articles, the eruption started on 16 March from two vents, one on Hunga Ha'apai and another about 100 m offshore. Video footage and photographs taken from a nearby boat and posted on 20 March showed repeated dark, ash-rich Surtseyan explosions and associated base surges from two vents. A journalist that visited the area reported that the island was covered with black ash, and coconut trees were reduced to black stumps. Dead birds and fish were seen in the water.

The small islands of Hunga Tonga and Hunga Ha'apai cap a large seamount located about 30 km SSE of Falcon Island. The two linear andesitic islands are about 2 km long and represent the western and northern remnants of a the rim of a largely submarine caldera lying east and south of the islands. Hunga Tonga and Hunga Ha'apai reach an elevation of only 149 m and 128 m above sea level, respectively, and display inward-facing sea cliffs with lava and tephra layers dipping gently away from the submarine caldera. A rocky shoal 3.2 km SE of Hunga Ha'apai and 3 km south of Hunga Tonga marks the most prominent historically active vent. Submarine eruptions were reported here in 1912 and 1937 and from a fissure 1 km SSE of Hunga Ha'apai in 1988.

The Current Colour Code for Hunga Tonga is ORANGE
~~~~~~~~~~~~~~~~~~~~

KARYMSKY

As of the 8th of May, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that gas-steam activity of the volcano continues but a possibility of ash explosions up to 6.0 km (or 19,700 ft) ASL remains. The explosive activity of the volcano could affect low-flying aircraft. Seismicity was at background levels last week but there was not the data by technical reasons on May 3rd-5th. According to satellite data, a weak thermal anomaly was registered over the volcano on May 6th.

Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, which is located immediately south of Karymsky volcano. The caldera enclosing Karymsky volcano formed about 7600-7700 radiocarbon years ago; construction of the Karymsky stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-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.

The Current Colour Code for Karymsky is YELLOW
~~~~~~~~~~~~~~~~~~~~~

KILAUEA

As of the 12th of May, the Hawaiian Volcano Observatory (HVO) reports that glow from the Halema`uma`u vent continues to be bright. Lava from east rift zone vents continues to flow through tubes to the coast and is entering the ocean at two locations west of Kalapana. Sulfur dioxide emission rates from the Halema`uma`u and Pu`u `O`o vents remain elevated.

Last 24 hours at Kilauea summit: A molten lava pool remains near the base of the cavity deep below the floor of Halema`uma`u Crater producing the brightest glow from the summit vent since early December 2008 (recorded by both webcams pointed at it - see HVO's new "Webcams" link at hvo.wr.usgs.gov). This morning, the gas plume rises high above the Halema`uma`u Crater rim and is currently moving to the west. Sulfur dioxide emission rates remain elevated and variable; the most recent rate measurement was 700 tonnes/day on May 10th, compared to the 2003-2007 average rate of 140 tonnes/day. Tremor levels slowly increased and are near the Friday morning values. One earthquake was located beneath the summit and four earthquakes were located on south flank faults. The number of RB2S2BL earthquakes were within background levels. The network of tiltmeters at Kilauea's summit switched to recording weak to no deflation. The GPS network (less sensitive than the tiltmeter network) has recorded about 1 cm of contraction across the caldera over the past 3 months.

Last 24 hours in the middle east rift zone vents and flow field: Magma continues to degas through Pu`u `O`o Crater before erupting from vents to the east. The most recent measurement was 1,400 tonnes/day measured on May 8th, compared to the 2003-2007 average of about 1,700 tonnes/day. No incandescence was recorded within the crater overnight. The tiltmeter on the north flank of Pu`u `O`o stopped reporting to HVO just before 0800 hrs Saturday; technicians will resolve the problem this week. GPS receivers on opposite sides of the crater have documented about 1.5 cm of contraction over the past month and more than 5 cm over the past 3 months. Seismic tremor levels near the eruptive vents are low and steady. Lava from the TEB vent and the rootless shield complex flows through tubes to the ocean at Waikupanaha and Kupapa`u. CD officials reported stable conditions at both ocean entries with a brief period of explosions and intense glow around 1930 hrs. This morning, two plumes are visible from Kalapana indicating that both entries are active.

Kilauea volcano, which overlaps the east flank of the massive Mauna Loa shield volcano, has been Hawaii's most active volcano during historical time. Eruptions of Kilauea are prominent in Polynesian legends; written documentation extending back to only 1820 records frequent summit and flank lava flow eruptions that were interspersed with periods of long-term lava lake activity that lasted until 1924 at Halemaumau crater, within the summit caldera. The 3 x 5 km caldera was formed in several stages about 1500 years ago and during the 18th century; eruptions have also originated from the lengthy East and SW rift zones, which extend to the sea on both sides of the volcano. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1100 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.

The Current Colour Code for Kilauea is ORANGE
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