ECUADOR - Guagua Pichincha volcano

March 14th , 2008

As of the 12th of March, the Instituto Geofísico (IG) has reported that the activity of the volcano stays in a low level, nevertheless during this week registered a slight increase in the number of volcano-tectonic events, which are related to rupture of rock to the interior of the volcano. Possibly this activity must to a change in the field of efforts within the hydrothermal system of the volcano due to the entrance of a greater amount of fluids, specially from the surface (meteoric water or of rain). As of the 20th of February, the IG reported that after the emissions of the 31st of January and 1 February, the phenomenona phreatic eruptions has not come to register again, but the fracture events continue, without presenting/displaying other new features. The 10th of February a visit became and it was observed that apparently that the source of these emissions would be in the part of back of the 1999 dome, in view of which were not observed evidences in the previous sector of the boiler. As of the 7th of February, IG reported that seven moderate phreatic explosions from Guagua Pichincha occured on 1 February, following a few weeks of slightly increased internal activity and a few days of almost constant precipitation. For weeks back a slight increase of the internal activity of volcano Guagua Pichincha has been noticing, situation that next to almost constant precipitations of the last days has caused that on Friday, the 1st of February, 7 phreatic explosions of moderate size have appeared, due to an increase of the internal steam pressure. Therefore the Geophysical Institute recommends the visitors of the volcano not to descend to the interior of the crater since this type of events could be repeated and to be extremely dangerous for the people they could take the rock hit, other materials and/or rarefaction waves that are generated by these explosive events. These steam explosions happen generally at times of much rainfall, which is the reason why these explosions not necessarily are indicative of a substantial increase of the activity of volcano Guagua Pichincha. The Geophysical Institute in its eagerness to preprevent the security of the people maintains a monitoring permanent of the state of this and other volcanoes of the country and will inform opportunely into any change that these can present/display. Guagua Pichincha rises immediately W of Quito, Ecuador's capital city. The broad volcanic massif is cut by a large horseshoe-shaped summit caldera, ~6 km in diameter and 600 m deep, that was breached to the W during a slope failure ~50,000 years ago. - Information : I G Quito

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ECUADOR - Tungurahua volcano

May 9th, 2008

As of the 9th of May, the Instituto Geofísico (IG) has reported that the seismicity is similar to the previous days, associated to movement of fluids, appearing additionally 2 little power explosions. Ash falls in the environs, noises, rains nor lahars have not been reported. The IG reported that a total of 41 events of long period (LP's) and 73 episodes of tremor of continuous emission, 2 explosions 0331hrs, DR=1.47, have been registered one at 0916hrs, and the other with a DR= 2.38. The emissions observed, with ash mean load, reached heights smaller 1 km on the summit, with preferred directions to the west. The climatic conditions around the summit of the volcano you have been cloudy and partially cloudy. As of the 7th of May, the IG reported that although visual observations were occasionally limited due to cloud cover during 29 April-6 May, ash-and-steam plumes from Tungurahua were spotted and generally rose to altitudes of 5.5-7 km (18,000-23,000 ft) a.s.l. Ashfall was reported in areas to the SW and W during 29 April-1 May and on 4 May. On 30 April, explosions produced steam-and-ash plumes to altitudes of 9-10 km (29,500-32,800 ft) a.s.l. Incandescence at the summit was visible and incandescent blocks rolled down the flanks. Roaring noises were audible. On 1 May, explosions were accompanied by "cannon shots" and intense incandescence at the summit. Windows vibrated in areas 6 km NE. Incandescent blocks rolled 1 km down the flanks. On 3 May, a small lahar descended the W flank. As of the 2nd of May, the Instituto Geofísico (IG) has reported that at night yesterday 1st of May, incandescence in the zone of the crater was observed. This day, the ash fall was reported in the population of Pillate. The volcano continues showing signals of gas discharge and ash and two explosions of moderate size were registered. Lahars have not taken place. The IG also reported for seismicity a total of 55 LP`s events which has been entered, 2 episodes of tremor of emission and two explosions. The explosion of greater size happened at 0157hrs of today. Ash, emissions and observations. At night yesterday, intense brightness in the zone of the crater and rolling of incandescent blocks by flanks of the volcano was observed. At dawn and today the ash fall was reported in the population of Pillate. As of the 25th of April, IG reported that the seismic activity continues such in levels of activity of the previous days and it is characterised by an important number of events that indicate movement of fluids. Unlike the previous days the explosions have caused clear signals audible that they have caused vibrating of large windows and the ground in the environs. Ash fall has not been reported nor have taken place lahars. The IG reported that seismicity: A total of 108 events of long period (LP), 30 episodes of tremor of emission and 2 small explosions has been entered (smaller to 3.5 cm 2 ). Ash, emissions and observations: Most of the time the volcano has remained dimmed which is the reason why the visual reports are limited. To first times of the night two explosions happened yesterday (0033hrs and 0410hrs) which produced strong cannon shots and columns with average ash content and direction towards the W-SW. With the explosion of 0033hrs from the OVT it was observed blocks rolling to about 600 m under the level of the crater. These explosions caused vibrating of windows and the ground in the sectors of Pillate, Cusúa, Choglontus, Palitahua and Cahuají and also was heard rolling of these blocks in several sectors around the volcano. Rains and lahars: Rains nor lahars have not appeared. Noises: To part of the noises and cannon shots produced by the explosions one has not had reports of another type of originating acoustic signals of the volcano. As of the 18th of April, the Instituto Geofísico (IG) reported that the seismicity stays in moderate levels, with the occurrence of an important number of events that indicate movement of fluid and that it is similar in number to the registered thing in the previous days. The existing cloudiness around the volcano has not allowed to have visual observations. They have not registered lahars, falls of ash nor roars. The IG reports that seismicity: A total of 158 events of long period (LP), 18 episodes of continuous tremor of emission and 1 explosion. Ash, emissions and observations: The volcano has remained covered by clouds during all the day, situation that it has prevented to have visual observations. The night yesterday at 0429hrs a small explosion was registered, the same one that could not be observed due to the cloudiness that existed around the volcano. One does not have reports of ash fall. Rains and lahars: Rains nor lahars have not appeared. Noises: In last the 24 hours one has not had reports of roars or originating noises of the volcano. Tungurahua is a steep-sided stratovolcano or a conical volcano composed of many layers of hardened lava, tephra, and volcanic ash and is located near Ecuador's fourth largest city of Ambato, some 140 km south of the capital Quito. Tungurahua -

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ECUADOR - Reventador volcano

July 10th, 2007

As of the 10th of July, the Instituto Geofisico (IG), reported that the seismicity continues related to events of fracture due to the internal pressure of flowed (HB and VT) but is not observed much movement of these fluids (under number of events LP and absence of tremor). There are no observations due to the cloudiness nor reports of no new features. By the characteristics of the seismicity, as far as the type of events and in general to that these have diminished in magnitude, superficial manifestations of importance in the short term are not expected (like explosions, emissions of ash or lava flows). Therefore, the daily information are suspended and will be emitted solely if the the situation merits. The forested, dominantly andesitic Volcán El Reventador stratovolcano rises to 3562 m above the jungles of the western Amazon basin. A 4-km-wide caldera widely breached to the east was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1300 m above the caldera floor to a height comparable to the caldera rim

ECUADOR - Sangay volcano

March 10th, 2007

As of the 8th of March, the Instituto Geofisico (IG), reported that based on information from the Guayaquil MWO and satellite imagery, the Washington VAAC reported that a notable eruption from Sangay on 28 February produced an ash plume that rose to an altitude of 7.6 km (25,000 ft) a.s.l. On 2 March, a diffuse plume and a weak hotspot were seen on satellite imagery. On 5 March, a pilot reported that an ash plume rose to between 5.2-6.1 km (17,000-20,000 ft) a.s.l. and drifted W. The isolated Sangay volcano, located east of the Andean crest, is the southernmost of Ecuador's volcanoes, and its most active. The dominantly andesitic volcano has been in frequent eruption for the past several centuries. The steep-sided, 5230-m-high glacier-covered volcano grew within horseshoe-shaped calderas of two previous edifices, which were destroyed by collapse to the east, 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 east 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 a 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.

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MONTSERRAT - Soufriere Hills volcano - West-Indies

May 9th, 2008

Report for the period from 5th of April to 7th of May 2008- As of the 7th of May, the Monstserrat Volcano Observatory (MVO) reported that there was a small pyroclastic flow on the eastern flank of the Soufriere Hills volcano at 0200hrs on Monday 5th May. Light ashfall was reported in the Old Town area. The flow may have been triggered by very heavy rainfall at the time, which also generated lahars. A brief swarm of volcano-tectonic earthquakes occurred at the same time as the flow. These were located at a very shallow depth beneath the dome. The alert level remains at 4. As of the 26th of April, MVO reported that the pause in dome growth at the Soufriere Hills Volcano continues. Measurable activity remained low with no significant change throughout the last week. Helicopter observations on the 24th of April showed that gradual erosion of the talus is continuing on the eastern flank of the dome to reveal the more resistant solid lava beneath. There were good views of the western and southern flanks of the dome due to the change in wind direction. Two small pyroclastic flows were observed on 16 April at around 1500hrs and 1515hrs. The larger flow travelled approximately 1 km down the eastern flank of the dome and was followed by relatively strong degassing immediately afterwards. Recorded seismic activity remained relatively low with eight rockfall signals being recorded. 1 volcano-tectonic earthquake was also recorded during the reporting period. The recorded sulphur dioxide (SO 2 ) flux for the period ranged from a minimum of 283 tonnes per day (t/d) on 16 April to a maximum of 658 t/d on 13 April. The average flux rate for the period was 422 t/d. Whilst lava extrusion has ceased and the dome may not be actively growing, it remains a large mass of mainly hot lava capable of collapsing or exploding. The likelihood of this should decrease with time as it slowly cools with no fresh lava extrusion. During heavy rain lahar activity in river valleys around the volcano remains a potential hazard. The alert level remains at 4. A previous small pyroclastic flow was also observed on the 10th of April at around 1730hrs. This small flow travelled approximately 500 m down the eastern flank of the dome and generated a small ash cloud which was quickly dissipated over the Plymouth area by the wind. A similar small pyroclastic flow was last observed on the 2nd of March. Recorded seismic activity remained low with one rockfall signal and one pyroclastic flow signal. 5 volcano-tectonic earthquakes were also recorded during the reporting period. The recorded sulphur dioxide (SO 2 ) flux for the period ranged from a minimum of 716 tonnes per day (t/d) on 8 April to a maximum of 1322 t/d on the 5th of April. The average flux rate for the period was 991 t/d. Whilst lava extrusion has ceased and the dome may not be actively growing, it remains a large mass of mainly hot lava capable of collapsing or exploding. The likelihood of this should decrease with time as it slowly cools with no fresh lava extrusion. During heavy rain lahar activity in river valleys around the volcano remains a potential hazard. The alert level remains at 4. http://www.mvo.ms - Information : Montserrat Volcano Observatory : View latest NOAA satellite image of Montserrat ( every 30 mn)
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MEXICO - Popocatepetl volcano

May 9th, 2008

As of the 9th of May, the El Centro Nacional de Prevención de Desastres de la Secretaría de Gobernación (CENAPRED) has reported that in the last 24 hours the monitoring system again detected 3 exhalations acompanied by steam and gas. Also, yesterday at 1543hrs (local time), a volcano-tectonic earthquake was detected with magnitude 2.3. The other monitored parameters remain without important changes. At the moment of this report CENAPRED does not have visibility due to clouds. During previous hours a steam and gas emission was observed. 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, 5426 m high is located at 70 km SE of Mexico City . The glacier-clad stratovolcano contains a steep-walled, 250-450 m deep crater. 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, have occurred since precolumbian time. . Information from CENAPRED - Live cam of Popocatepetl

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MEXICO - Colima volcano

May 9th, 2008

As of the 9th of May, the Government of the State, through the State Unit of Civil Defence-Colima reports that in the last 24 hours, the monitoring of the Colima volcano that the equipment of monitoring of the Colima volcano registered two exhalations during last the twenty-four hours, without any reports on damages or affectation in the adjacent populations, informed the Government into the State, through the State Unit of Civil Defence Colima. Yesterday afternoon, the top of the volcano was covered by cloudiness, a phenomenon caused by humidity the originating flows of the Pacific Ocean and Gulf of Mexico; so possibility persists also of establishment of clouds or light rains in this zone, which is the reason for which is necessary to remind the population to avoid the permanence in bordering ravines, before the possibility of lahars (mud flows). On the other hand, it continues the restriction for the over-flights 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, until today two exhalations of gray colour could be detected, with a vertical direction; whereas the first, happened at 0859 hours, one rose 400 metres of height on the level of the dome, the second, at 1020 hours, it diminished slightly, because its height was 380 metres. . Colima's web video camera -

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GUATEMALA - Fuego volcano

May 9th, 2008

As of the 9th of May, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that activity was characterized with weak Fumaroles to low height in direction the northwest. In the course at night they have been observed and heard were 13 explosions accompanied by moderate rumblings, generating sensible shock waves to several kilometres of the volcano, also degassing sounds similar to turbines of airplane by lapses of 10 minutes were heard. The explosions have been weak, moderate and strong, expelling gray ash to 300 to 900 metres, on the crater, forming columns of 7 kilometres in length, moving to the west. Constant avalanches of blocks on the ravine Santa Teresa. As of the 1st of May, INSIVUMEH reported that the Washington VAAC reported that an ash plume from Fuego was visible on satellite imagery on 23 April and drifted SW. Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. Frequent vigorous historical eruptions have been recorded since 1524 and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua. From (INSIVUMEH)

GUATEMALA - Santa Maria - Santiaguito

May 9th, 2008

As of the 9th of May, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that activity observed was a moderate explosion expelling gray ash 700 metres of height moving to the southwest, on the zone of Palajunoj. In the crater of the Domo Caliente, with abundant degassing. As of the 1st of May, INSIVUMEH reported that based on observations of satellite imagery, the Washington VAAC reported that an ash plume from Santa María's Santiaguito lava dome complex rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted SW on 25 April. On 28 April, INSIVUMEH reported that weak explosions produced ash plumes that rose to an altitude of 4.1 km (13,500 ft) a.s.l. and drifted W. As of the 22nd of April, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that few explosions, have been observed between weak and moderate expelling ash-gray gray 300 and 800 metres from height dispersing the east, on the property Patzulin, the light and regions of Santa Maria de Jesus. Little activity by avalanches on the lava flows flank the west and the south. As of the 16th of April, INSIVUMEH has reported that activity was characterized with 3 explosions, 2 weak and 1 moderate one expelling gray ash to 300 and 900 metres from height dispersing to the southwest by 5 kilometres on the property Florida and Claro Mount. Constant avalanches give on the lava flows flank the west and the south. The renowned plinian eruption of 1902 followed a long repose period and devastated much of SW Guatemala. The large dacitic Santiaguito lava- dome complex has been growing at the base of the 1902 crater since 1922.(GVN/GVP)

GUATEMALA - Pacaya volcano

May 9th, 2008

As of the 9th of May, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that the seismic activity that is registered in PCG is of superficial events associated with small explosions and tremor for moments (vibration internal) due to the exit and drag lava flows. On the Mackenney crater, white fumarole of water steam stays mainly and volcanic gases, the plume moves towards the west of the volcano. The lava flows, continue fed by fissures in the part the northwest on the volcano, flowing within the plateaus these, constantly change of direction and size, in front of the Cerro Chino, reaching of 150 to 250 metres in length. As of the 16th of April, INSIVUMEH reported that activity since the reactivation of the volcano of Pacaya, of the present period to lasted 2 years already, this to consisted mainly of lava effusion, from fissures of the low part of the volcanic complex, where the flows are fed on lava, those that have caused the flowing of great part of the north of the plateau. Also there are short periods in the activity where small explosions of Strombolian type nevertheless these are observed have been of little duration of 2 to 3 days per month. Changes in the volcanic complex exist from their reactivation are deep cracks with direction the north-south, the modified crater this approximately has a depth of 15 metres by a diameter of 10 to 15 metres. As far as the activity of gases one stays with moderate fumarole of gases of white and blue colour accompanied by water steam. All this activity also is registered through the seismic station of PCG which allows to determine, volcanic events, by ascent of magma and drag lava in the surface. As of 16th of April lava flows continue on the flank the northwest of the plateau, moving in several directions, now the main flow this patch to the wall of the plateau with direction the northwest, burning the low part of the vegetation reaching the 400 metres in length. 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. 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.

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SALVADOR - Santa Ana volcano

June 9th, 2006

As of the 8th of June, the Global Volcanism Network (GVN) reported that the activity of the volcano Santa Ana is found very near its normal behaviour base line. Analysis is in agreement to the analysis of the last data obtained of the seismic monitoring, dioxide of sulfur, temperature of fumaroles and the visual observations, they indicate that the volcanic system is stabilized, reaching levels of activity that can be considered normal for a volcano that recently did Warning Level eruption Previous weeks, the seismicity of the volcano has been characterized for the earthquake tremor pursued of high frequency during periods of small time to 20 minutes. The frequencies of the tremor and other associated signs with phreatic activity are moderate between 3 and 12 hz. The amplitudes of the seismic signs (RSAM) basically have been fluctuating between 10 and 20 units, which is quite stable. It fits to mention that during the periods of tremor, the RSAM reached sporadic peaks of to 70 units. The behaviour of the volcano, is anomalous, since after the eruption of October 1, 2005, its seismic activity has been maintained fluctuating between 60 and 80 units of RSAM, that is to say, three to four up the times of the normal (the normal was 20 units). It more prominent of the activity of the volcano after the eruption of October, was the registration of 37 seismic swarms on Saturday 26 of November that was comprised of microseismics associated to breaking of rocks. A similar situation was registered last Tuesday 29 in hours at night. The previous thing indicates that for periods of few days to weeks, significant fluctuations in the seismicity of the volcano are produced, associates in exchange for pressure exercised by the gases of a magma that is found in process of desgasification. Activity Settings of probable threat The settings that can be presented they continue being two: - Without eruptive activity: the volcano continues its activity, to descend to its normal ranks. - With eruptive activity: fast or sudden changes in the parameters are registered that are monitored, that culminate in eruptive activity. The eruptions could be:? Phreatic eruption: explosions of gas that drag solid materials (ash and blocks) existing in the crater and in the volcanic conduits, that can be hot by the contact with gases magmatics. Similar eruption to it occurred the day 1 Oct 05. Eruption phreatomagmatic (mixture of the magma with superficial or subterranean water) or magmatic: the explosions of gas go accompanied with the exit of lava in the shape of fragments (ash, lapilli, blocks and volcanic bombs according to their size in which they solidify in their traveled through by the air. The largest fragments fall around the volcanic cone in a maximum radio of 3.5 kilometers. The transportation and deposition of the ashes, by its fine size, will be influenced by the predominant winds. The weather forecast of wind for the next days, in levels over the 1.500 m. s. n. m, indicates that the winds will be of northeastern component with velocities of 20 km/h therefore, in case to be produced eruption the dispersion of ashes would be predominantly toward southwest. In any of the settings of volcanic activity, still without eruption, they would be able to be produced new flows of debris (lahars), by the dragging of the loose material that still exists in the interior of fractions and you split high of the volcano, in case to be produced rains. As of the 3rd of October, SNET, was reported that Santa Ana volcano has erupted. The eruption started at about 1400Z on 1 October. The microseismicity has experienced an important descent. From first hours in the afternoon of yesterday significant fluctuations in the seismic level of the volcano have been registered. The RSAM presented a significant decrease varying the daily average since 84.0 units (10/01/05) to an average of 30 units to the 1100 today. At 1300 hours of the yesterday a seismic swarm of 4 small events of low frequency was registered. Since the 1950 hours to 2130 was registered tremor of greater amplitude with a small earthquake of fracture, and to the 2310 initiated again another (tremor) of greater amplitude, finalizing to the 0000 hours. The tremor is characterized for presenting drops in frequencies with diverse discreet events. During the afternoon and night of yesterday, and even the hour of emission of this report (1130) no earthquakes were sensed by the population have been registered. Due to the weather conditions there is no steam column height report. Sulfur Dioxide flow measurements (SO2) carried out yesterday by the research team of the University of El Salvador, had an average of 2,925 t/d was obtained for the day. During morning of today the measurements reported are around 250 t/d. With respect to water, there is no influence of the activity of the volcano in the water of the Squat Hill has been found, of the lake of Coatepeque. Images of satellite taken during the eruption by NOAA reported a column from 10 to 12 Km. of height approximately. The activity of the volcano continues anomalous, presenting levels between the 30 and the 70 units RSAM. The parameters of seismicity, that is to say, RSAM, discreet events and Sulfur Dioxide emissions (SO2), they present significant changes with relation to the last 10 days. The measurements of SO2 have presented an important decrease with relation to the maximums of the previous days. From different thicknesses of ash found during the visits from field the day of yesterday, it is estimated that the volume of ash emitted during the eruption, is of at least 1.5 million meters cubic.as has come mentioning before, the behaviour of the volcano Santa Ana is unpredictable; similar situations to it stirred up yesterday would be able to be repeated whether in greater or smaller The National System of Emergency, that at present is facilitating the information to be calm and obey instructions. The settings that can be presented they continue being two: - Without eruptive activity: evolution of the activity toward normal.- With eruptive activity: changes in the parameters being accelerated and culminating in eruptive activity are registered. Observations The volcanic caution is maintained intensified Level of Warning The COEN maintains the RED WARNING around the volcanic building, in an area of 4 kilometers of radio from the central crater. As of 1st of October SNET was reported that following past days of important seismicity an eruption started on Saturday morning. Explosive activity occured with lava incandescent materiel ejection and (unconfirmed lava flow on South flank ? ). The volcano plume reached about 15 km elevation. Important ashfalls occured around the volcano and the poplation living near the volcano was rapidly evacuated. The eruption triggered a hot mudflow from the summital crater lake that rushed onto the hamlet of Palo Campana located about 2 km from the crater. Rocks and ash rained down on the village in the coffee growing area. Preliminary information report that two people died and seven people were injured by incandecent rocks spewed into the air during explosive activity. The color alert code is red. A radius danger zone of 4 km was established by the local autority. (further details as soon as possible). Santa Ana, El Salvador's highest volcano, is a massive stratovolcano (2365 m) immediately W of Coatepeque caldera about 65 km of San Salvador. 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.Previous historic activity occured in 1904. information from : SNET

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COSTA RICA - Arenal volcano

April 14th, 2008

In March, activity originating from Arenal's Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches from lava-flow fronts that traveled down the SW flanks. Volcanic
activity was at relatively low levels and few eruptions occurred. Acid rain and small amounts of ejected pyroclastic material affected the NE and SE flanks. Eruptions produced ash plumes that rose about 2.2 km
(7,100 ft) a.s.l. Small avalanches of volcanic material traveled down several ravines. Crater D showed only fumarolic activity.Previously OVSICORI-UNA confirmed that a pyroclastic flow from Arenal traveled W on 18 september 2007. The event was recorded by a local seismic station. Based on field observations, a scientist from Instituto Costarricense de Electricidad (ICE) reported that multiple pyroclastic flows traveled S an approximate distance of 1 km on 18 September. Explosions occurred that occasionally produced ash. Small avalanches were noted and one larger avalanche on the S flank was incandescent. Avalanche activity continued on 19 September. Conical Volcán Arenal is the youngest stratovolcano in Costa Rica and one of its most active. The 1657-m-high andesitic volcano towers above the eastern shores of Lake Arenal, which has been enlarged by a hydroelectric project. Arenal lies along a volcanic chain that has migrated to the NW from the late-Pleistocene Los Perdidos lava domes through the Pleistocene-to-Holocene Chato volcano, which contains a 500-m-wide, lake-filled summit crater. The earliest known eruptions of Arenal took place about 7000 years ago, and it was active concurrently with Cerro Chato until the activity of Chato ended about 3500 years ago. Growth of Arenal has been characterised 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.

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COSTA RICA- Poas Volcano

January 25th, 2008

As of the 25th of January, the Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI-UNA) has reported that a visit on January 18th, 2008 confirmed a report that a small phreatic eruption occurred within the perimeter of the hot-acidic lake of Poás volcano, around 0900hrs on Sunday, January 13th, 2008. The first notice was given by a park ranger and described as cipresoidal shape with ejection of water and sediments out of the center of the lake. It did reach some 200m high and subsequently collapsed to change rapidly the lake's colour from a dark green to an intense white. This event was also witnessed by a group of tourists who were temporarily evacuated but were always safe at some 1200m, observing the volcano from the main viewpoint. Field inspection revealed also that the explosion produced a wave of 1.5m all around the lake leaving a mark along its rim. Only to the south, next to the north dome's terrace, squirts of sediments were found reaching distances of some 8m from the shore. Such sediments were washed off, probably by the returning wave and reached a thickness no greater than 10cm. Such pockets of sediments contain a large quantity of shining crystals and other pre-existent minor debris from the bottom of the lake. No blocks were expelled out of the lake. The person that made the first report emphasised the calm conditions of the lake and dome before the eruption. Also, a small landslide (8x20m) was documented on the north face of the dome. It did leave a chaotic deposit of heavily altered angular blocks in a gray matrix altered by hydrothermalism. A slurry of yellowish materials reached the edge of the lake. Due to rapid outlet of gases in concentric convection cells from the centre of the lake, the lake changed its colour progressively in a matter of some 3 hours during the visit of OVSICORI´s staff. Even more, rapid degassing from the surface of the lake impedes the sight to the other side, due to thick columns of toxic gases. Lake temperature dropped to 45ºC and water level raised 1.5m compared to the last estimate at the end of November 2007. Nonetheless rapid evaporation promotes rapid reduction of such level. 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 2,708-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 7,500 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.

COSTA RICA - Turrialba volcano

December 7th, 2007

As of the 7th of December, the Observatorio Vulcanológico y Sismológico de Costa Rica. OVSICORI-UNA has reported that from the first light this morning and to the begining of the day, (when it was covered with clouds) a high gas column could be observed that was given off from Turrialba volcano. Such observation could be made from Heredia and other sectors of the Central Valley with Vista line. At 0540hrs the column could above reach a height of 2kms on the top, approximately. Report of neighbours located on the foot (towards the west and to the south) mentions a white and bulky column that was given off from the crater the west. With base in such descriptions it is possible to be deduced by the colour and the height, a strong gas injection in vertical form. Columns similar (although smaller) have been observed in previous months when the atmospheric conditions are stable. In the last weeks the marching and burns of grass has been become serious. Reports of neighbours who inhabit villages indicate a greater volcanic gas presence in their houses which is increased by the acceleration of tradewinds. Those winds move gases to greater distances and they maintain against the external walls of the volcano and low zones grazing. Civil employees of the OVSICORI also have observed a slight expansion of the affectation by gases towards zones of annual cultures. SVE Volcanic fieldtrip 2008

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NICARAGUA - Apoyeque volcano

September 26th, 2007

As of the 24th of September, the Instituto Nicaragüense de Estudios Territoriales (INETER) informed that on Friday, 21 of September of 2007, began a seismic cluster in Apoyeque Volcano, located to about 8 kilometers to the Northwest of Managua in Nicaraugua. This activity has intensified and yesterday, the 23rd of September, the seismic network has located 10 earthquakes with Richter magnitudes up to 2.8. In addition, tens of earthquakes smaller were registered than they are only detected in the located seismic station in the crater of the volcano. This activity can continue by several days and the occurrence of greater earthquakes with magnitudes from 4 to 5 does not discard. Apoyeque volcano has not presented/displayed volcanic activity in historical times and at the present time it is not considered like imminent a volcanic danger. But, occasionally seismic clusters in the volcano and its environs are registered. In January of 2001, a very intense cluster with an earthquake greater than it had the magnitude 5.2 Richter and that it was strongly felt in Managua and Sandino City, without causing damages. INETER continues watching the seismic activity and will inform on any important event. The Apoyeque volcanic complex occupies the broad Chiltepe Peninsula, which extends into south-central Lake Managua. The peninsula is part of the Chiltepe pyroclastic shield volcano, one of three large ignimbrite shields on the Nicaraguan volcanic front. A 2.8-km wide, 400-m-deep, lake-filled caldera whose floor lies near sea level truncates the low Apoyeque volcano, which rises only about 500 m above the lake shore. The caldera was the source of a thick mantle of dacitic pumice that blankets the surrounding area. The 2.5 x 3 km wide lake-filled Xiloá (Jiloá) maar, is located immediately SE of Apoyeque. The Talpetatl lava dome was constructed between Laguna Xiloá and Lake Managua. Pumiceous pyroclastic flows from Laguna Xiloá were erupted about 6100 years ago and overlie deposits of comparable age from the Masaya plinian eruption. The colour code at Apoyeque is currently at YELLOW . .

NICARAGUA - Conception volcano

December 21st, 2007

As of the 21st of December, the Instituto Nicaragüense de Estudios Territoriales (INETER) informs that the volcanic activity of the volcano Concepcion, in the Island of Ometepe, that gave to beginning the 24 of November, continues. Yesterday, 20 December, another episode of the volcanic activity occurred, with the emanation of gases and ashes. At 1230hrs a small explosion, followed of gases and ashes took place, in moderate amounts. Civil Defence reported that the thrown ash, was deposited in small amounts in the Island of Ometepe and was transported by the wind towards the municipalities of San Jorge, Bethlehem, Potosí and Buenos Aires, Department of Rivas. No earthquake has been registered by the located seismic stations in the Island of Ometepe. At the time of sending this official notice this activity has diminished considerably. INETER continues monitor volcano Concepcion and will inform on any new event of importance . The symmetrical basaltic-to-dacitic stratovolcano forms the NW half of the dumbbell-shaped island of Ometepe in Lake Nicaragua and is connected to neighbouring Madera volcano by a narrow isthmus. A steep-walled summit crater is 250 m deep and has a higher western rim. Frequent explosive eruptions during the past half century have increased the height of the summit significantly above that shown on current topographic maps and have kept the upper part of the volcano unvegetated

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COLOMBIA - Galeras volcano

May 9th, 2008

As of the 7th of May, the Observatory Vulcanológico and Sismológico de Pasto - INGEOMINAS, informed that the predominant seismicity was associate with flowed processes of dynamics of of hydrothermal and magmatic origin which was concordant with the observations of the column of gas discharge that reached heights of up to 1700 m and which it could be appraised from the city of San Juan de Pasto and neighbouring populations, in addition to an increase in the flow of SO 2 emissions. The volcano stands out with an increase in the occurrence of earthquakes that jointly involve processes of dynamics of fluid and fracturing of cortical material that demonstrates contemplated own changes within the present behaviour of the volcanic activity. As of the 22nd of April, INGEOMINAS, informed that the seismic activity of the volcano remains in low levels, in occurrence as in energy as much released. Although the seismicity that predominates follows associate with flowed processes of dynamics of of hydrothermal origin and magmatic, in the last days an increase in the activity associated with processes of fracturing of cortical material was observed. Most of these earthquakes was located in neighbourhoods of the main crater and to smaller depths of 2 km, with smaller local magnitudes of 2.0 on the Richter scale. The remaining events were registered of dispersed way in the volcanic complex, with smaller depths of 10 km with respect to the top of the volcano and local magnitudes smaller to 2.0 on the Richter scale. When the climatic conditions therefore allowed it, exit of gas could be appreciated, mainly constituted by water steam, that by the direction and the wind speed was observed from the western sector of the crater. The days of greater intensity in the seismicity were between the 15th and the 18th of March. The located earthquakes are located in their majority to the south of the active cone (specially to the southwestern flank), to smaller distances of 2 km and with depths that do not surpass 2.5 km, with respect to the top. This seismicity was not perceived by the people. At a level of superficial activity, in this last week some reports of gas discharge are had (mainly water steam) from different sectors from the active cone. The columns were of little height and its variable dispersion according to the wind direction. The evaluation of the Observatory on the registered change of activity, is that it is related to a process of intrusion of magma that has taken place gradually after the eruptive episode of the 17th of January of 2008. The 16th of February the process of activity of Galeras stayed, showing fluctuations and its development involves variable periods in the time. On Saturday, the 2nd of February, towards 1615hrs of the afternoon, it was possible to observe a column of gas discharge, of bluish gray colour, that reached near 300 m of height on the top and it tended towards sector SSE of Galeras. It is emphasised that the process of activity of Galeras stays, being able to show fluctuations and its development involves variable periods in the time. INGEOMINAS continues kind to the evolution of the volcanic phenomenon and will inform on changes that can be detected. Previous information : the Galeras volcano violently and soudainly erupted yesterday 17th of January at 806 pm prompting thousands of residents to evacuate the area. The region around the volcano is inhabited by some 8,000 people. However, f there were no reports of injuries or significant damage following Thursday's eruption. Volcanologists in Pasto volcano observatory expressed concern that shifting winds could spread the ash and cause damage to homes and other buildings. Preceding the eruption, there were five tornillo earthquakes measured between 0805hrs on January 16 and 0914hrs on January 17, 2008. The earthquakes were located near the active cone, close to the surface. About 8000 people have been evacuated. This is the most severe eruption at the volcano since it reactivated in 1989. Ash was reported to reach 36,000 ft. altitude. Also, the registry of five events Tornillo type between the 0805hrs of the 16th of January and 0914hrs of the 17th of January, located in environs of the active cone and to superficial levels. The importance of the occurrence of this type of events in Galeras, that is in preceded the eruptions of 1992 and 1993, which they appeared after the location of a lava dome in 1991; as well as they preceded some of the registered eruptives episodes between 2004 and 2006. On the other hand, as it were mentioned in the official notice of the 14th of January of 2008, the activity of Galeras continues showing of alternate way, lapses of diminution of seismicity followed of episodes of more recurrent activity, maintaining power levels low. Which remembers that to the interior of the main crater it remains a surplus of the lava dome located from end of 2005, partially was destroyed with the eruption of the 12 of 2006 July. INGEOMINAS continues very kind to the evolution of the volcanic activity and will opportunely inform the changes that can be detected..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.

COLOMBIA - Nevado del Huila volcano

May 9th, 2008

As of the 8th of May, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, INGEOMINAS reported that during the week of the 30th of April to the 6th of May, a total of 147 seismic events was registered. Of them, 64 are related to fracturing of rock, 71 with the dynamics of flowed within the volcanic conduits, 5 with mechanisms composed of fluid fracture and movement of and 7 pulses of tremor of low magnitude. In today a fly over was made to the volcanic complex. Although the direct visualisation of flanks NE was impossible and NW of the complex, did not demonstrate superficial changes significant associate with the activity of the volcano. In the visual inspection, fumarolic activity with dispersion was observed towards the NW flank. Of the previous, one concludes that the volcanic complex presents/displays low levels of activity, with slight excitations of the system As of the 30th of April, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, INGEOMINAS reported that during the present week (23rd to the 29th of April) demonstrated a diminution in the associated seismic activity to the internal dynamics of the volcanic system, in energy as much released, as in the number of registered earthquakes. In this period a total of 179 seismic events was registered. Of them, 88 events are related to fracturing of rock, 76 with the dynamics of flowed within the volcanic conduits, 6 with mechanisms composed of fracture and movement of fluids, and 9 pulses of tremor of low magnitude. Of the seismicity associated with fracture processes, stand out three seismic events registered days 25th of April at 1947hrs., 26th of April at 1101hrs and the 30th of April at 0107hrs. These events had magnitudes of 2.3, 2.1 and 3.5 respectively, and they were located to the NE of the Central Tip, with superficial depths (<5km).Today a fly-over was made to the volcanic complex. Although the strong winds disabled the direct visualisation of flanks NE and NW of the complex, did not demonstrate significant changes associate with the activity of the volcano. Of the visual inspection one stands out that a diminution of the flow of gases to surface exists, and evidences of loosenings of glacial mass towards the flank of the Central Tip, which form small flows of material in the high part of the complex, without reaching the channel of the Símbola. river. Of the previous thing, it is emphasised that the snow-covered volcano of the Huila, continued with significant changes in its behaviour during this week, and do not discard new increases in the activity. . As of the 3rd of April, INGEOMINAS reported that seismic tremor from Nevado del Huila increased during 18-25 March. Residents reported noises, the odour of sulfur, and small ash plumes. Seismicity increased again on 29 March; INGEOMINAS raised the Alert Level to Orange (on a 4-color scale, Orange is the second highest). As of the 27th of March, INGEOMINAS reported that during this past week between the 18th and the 25th of March of 2008 a total of 277 seismic events was registered. Of them, 142 events are associate to fracturing of rock, 134 events are related to the dynamics of fluid within the volcanic conduits and a pulse of tremor of low magnitude. During the present week, an increase of the seismic activity of the volcano snow-covered of the Huila is emphasised, during days 18th and 25th of March, represented by the registry of two seismic clusters of associated events fracturing of rock and transit of fluids. Also, the occurrence of two events associated to fracturing of rock is emphasised, On the 22nd and 25th of March, with magnitudes of 2.9 and 2.5, located in the Central Tip to smaller depths of 2 km. On the 25th of March, a movable measurement of SO 2 flow was made, on the Pan-American route Cali - Popayán, giving a flow of 655 tonnes/day, in a column with main dispersion towards sector NW of the volcano. The settlers of the defence of Huila have reported noises, a strong scent of sulfur and small exits of ash. Of the previous, the snow-covered volcano of the Huila is emphasised that, has experimented significant changes in its behaviour during the last week, which could imply that the volcano is between a greater phase of excitation than involves important ash emissions or smaller eruption . As of the 11th of March, INGEOMINAS reported that in the week between the 4th and the 10th of March of 2008 a total of 98 seismic events was registered. Of them, 47 events are associate to fracturing of rock, 49 events are related to the dynamics of fluid within the volcanic conduits and two pulses of tremor of low magnitude. Of the seismicity registered during the week the registry of three volcano-tectonic events is emphasised: first happened on the 4th of March at 0416hrs (local time), with a magnitude of 2.1, located at 3.8 km to the E of the Central Tip; the second, with a magnitude of 2.6, located was registered on the 7th of March at 2128hrs at 4 km to the NE of the Central Tip; and third happened on the 8th of March at 1833hrs with a magnitude of 2.04, located at 3.3 km to the E of the Central Tip. Of the previous, it is emphasised that the volcanic complex presents/displays low levels of activity, with slight excitations of the system. In days 8 and 12 of February, an approximated amount of 1371 tonnes/day was made movable measures of the flow of SO 2 in the Pan-American route Cali Popayán, obtaining itself day 8 of February, in a column with main dispersion to the N-W, and of 612 tonnes/day, day 12 of February in a column with dispersion in the same direction. Nevado del Huila, the highest active volcano in Colombia, is an elongated N-S-trending volcanic chain mantled by a glacier icecap. The andesitic-dacitic volcano (5635 m) was constructed within a 10-km-wide caldera. Only a single 16th-century explosive eruption is recorded in historical time from this little known volcano.

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PERU - Ubinas volcano

May 4th, 2008

A Based on SIGMET reports and observations of satellite imagery, the Buenos Aires VAAC reported that ash plumes from Ubinas rose to altitudes of 5.5-9.1 km (18,000-30,000 ft) a.s.l. and drifted NE, E,
and SE during 30 April-3 May. According to news articles, an ash-and-gas plume rose to an altitude of 6.2 km (20,300 ft) a.s.l. on 2 May. Ashfall was reported in local communities and dozens of residents of Querapi, about 4.5 km SE, were evacuated. Ubinas in 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. 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.

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CHILE - Chaiten volcano

May 9th, 2008

As of the 8th of May the Chaitén volcano continues to erupt ash and the 50 kilometres security exclusion zone around the volcano remained in force, reported ONEMI in a bulletin of 7 May 2008. Chilean Interior Minister Edmundo Pérez Yoma has appealed for people to co-operate in helping those who have been evacuated because of the Chaitén eruption, and has warned all those still in Chaitén and its environs to leave 'because they are at serious risk'.  The Chilean volcano Chaitén intensified its activity around midnight on Wednesday 7th/8th of May expelling ash and incandescent material, forcing the evacuation of all the military personnel and about 10 civilians who remained in the town closest to the peak. In the southern town of Chaitén, only 10km from the volcano, the total evacuation was ordered after pyroclastic material was seen to emerge from the cone of the volcano for a few minutes followed by dense columns of ash that fell on the surrounding area. ‘Army personnel have seen pyroclastic material, incandescent material, and there has been an increase in the sulphurous smell present in the town of Chaitén. As of 6th of May, latest SERNAGEOMIN bulletin online reported that eruptions continue for at Chaitén volcano. There have also been reports of a sharp increase in earthquakes in the area since the eruption. Evacuations have occurred at a second town, Futaleufu. Some residents have evacuated across the border to Argentina. Around 25,000 head of cattle in the area are in serious danger of dying. According to SERNAGEOMIN, during the morning of 6 May, at 08:20, the eruptive cycle went through a recrudescence with vigorous and rhythmic explosions of great energy producing a much wider laterally expanding eruptive column of about 30 kilometres altitude in its initial phase, declining subsequently. A subsequent helicopter overflight found that two craters on the northern side of the dome had joined into one, 800m-wide vent during this eruptive phase. (Assuming, as appears to be the case from photographs, that the initial site of the eruption was on the southern flank of the dome, it now seems that the volcano is erupting from both northern and southern flanks.) No pyroclastic flows were reported to the north, south or west (the eastern zone could not be inspected, presumably, being obscured by the eruption plume), and it was noted that the rivers around the volcano were carrying a greater load of erupted material. Overall SERNAGEOMIN considers that the eruption may develop in two ways from this point onwards - although, as always with predictions of volcanic activity, it is impossible to be sure. There is the possibility of a collapse of the eruptive column and/or the rhyolite dome, which would generate pyroclastic flows. On the other hand the fall of ashes may continue with accumulations whose thickness will depend on the intensity of the explosions and the prevailing winds. President Michelle Bachelet briefly visited Chaiten and spoke with some of the few remaining residents. At shelters in Puerto Montt, evacuees sought the president's support to rebuild outside the path of the volcano. Most of Chaiten's 4500 residents fled as the eruption polluted air and water supplies. As of 3rd of May bulletin, from the Chilean Government Emergencies Office ONEMI reported that eruptive activity was continued at the Chaitén volcano, with the sky darkened by ash and a constant fall of fine ash in nearby areas. A sulphurous smell has been reported in some districts. A number of earthquakes have also been experienced in the region over the past 24 hours. The volcano was still ‘erupting ashes' and covering the surrounding districts ‘with a dense cloud of ash more than 20km in height … In Chaitén town, the streets are covered with 20-40cm of ash'. The fall of ash from Chaitén is also causing problems in neighbouring areas of Argentina, where airports and schools have been closed, transport disrupted and water supplies affected. In the same bulletin ONEMI also reports that the evacuation of Chaitén is continuing, with the aim being to evacuate the whole population: From yesterday to dawn today a total of 3900 people have been evacuated by sea from Chaitén to Puerto Montt and Castro, which corresponds to 89% of the population … Today approximately 500 people will be evacuated on six vessels bound for Castro and Puerto Montt. This will evacuate the entire population of Chaitén. Previous news : following a short seismic crisis, the Chaiten volcano started an eruption. The Chaiten volcano ejected gas and ash on Thursday night 1st to 2nd of May 2008, causing more than 60 small tremors in the Los Lagos region, 750 miles south of the capital, Santiago.Chile's government declared a state of emergency, evacuating as many as 1,500 people from nearby villages and the town of Chaiten, just over 6 miles from the volcano considered dormant for thousands of years erupted. The blast sent minor earthquakes rippling through the region. The amount of ash falling in Chaiten had dropped considerably by Friday afternoon, and the wind was moving it southeast. Ash from the eruption was polluting water supplies and prompting officials to hand out more than 10,000 protective masks. Winds also carried ash over the Andes mountains to neighboring Argentina, where the Education Ministry suspended classes in several towns, including Esquel and Trevelin - two popular Patagonian tourist. Authorities also declared a state of alert on two major highways as falling ash reduced visibility. On Friday evening a Volcanic Ash Advisory stated that ash rose to altitudes in the range of 13.7-16.7 km. Chaiten lies slightly to the W of Minchinmavida. Chaiten volcano lacks any known modern eruptions but a radiocarbon date on its tephra (CHA1) yields a date of 7,430 BC (plus or minus 75 years). Chaitén is a small, glacier-free late-Pleistocene caldera with a Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf of Corcovado. The north side of the rhyolitic, 962-m-high obsidian lava dome occupying the 3.5-km-wide caldera is unvegetated. 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 1,122 m. Two small lakes occupy the caldera floor on the west and north sides of the lava dome.Informations : ONEMI, GVN/GVP - SERNAGEOMIN (in spanish)

CHILE - Llaima volcano

April 7th, 2008

SERNAGEOMIN reported that during 28 March-4 April, fumarolic plumes from Llaima drifted several tens of kilometers mainly to the SE. Explosions produced ash and gas emissions. An overflight on 2 April of the main crater revealed that gas, pyroclastic material, and ash emissions, occasionally accompanied by small explosions, originated from three cones. On 4 April, several explosions were heard and also some incandescence was reflected in a gas-and-ash plume. As of the 27th March, the El Observatorio Volcanológico de los Andes del Sur (OVDAS-SERNAGEOMIN) reported that fumarolic activity from the central pyroclastic cone in Llaima's main crater reactivated on 13 March and intensified during 15-17 March. Sulfur dioxide plumes rose to an altitude of 3.6 km (11,800 ft) a.s.l. and drifted E. People from nearby areas reported incandescence in the crater during 19-21 March. Incandescent material propelled from the crater was observed at night during 20-21 March. As of the 6th March, OVDAS-SERNAGEOMIN reported that weak sulfur dioxide plumes from two cones in Llaima's main crater during 26-28 February. An overflight on 28 February revealed that the internal structure of the crater had not changed since observations on 21 February. Weak fumarolic emissions from the main crater were noted during 2-3 March. The Alert Level remained at Yellow. As of the 28th February, a weak steam plumes were observed from Llaima's main crater on 20 February. The 'a'a lava flow that traveled 2.5 km during 2-13 February varied in width between 30-40 m and was 10 m thick. On 21 February small ash plumes rose from the E and SE flanks. Pyroclastic flows descended the E flank and possibly down the W flank. Sulfur dioxide plumes that rose from two craters within the main crater were visible during an overflight. On 22 February, a seismic signal pattern similar to that observed during a previous pyroclastic flow was noted. Ash-and-gas plumes rose from the E flank. On 23 February, an ash-and-gas plume rose from the SE flank. On 6 February, intense Strombolian activity that propelled material 500 m above the summit crater was observed. Ash-and-gas plumes from the activity rose to altitudes of 5.1-5.6 km (16,700-18,400 ft) a.s.l. and drifted SE more than 30 km. Multiple lava flows traveled 0.7-1.5 km W and N and generated steam plumes due to their interaction with a glacier. Activity declined later that day. During 7-8 February, explosions from two different areas in the main crater produced brown and gray ash-and-gas plumes that rose to altitudes of 4.1-6.2 km (13,500-20,300 ft) a.s.l. and drifted 20 km NW. Incandescent blocks from lava-flow fronts rolled down the flank. As of the 8th February, eruptive activity at Llaima continued from the main crater and from multiple areas on the E flank during 30 January-4 February. Lava flows extended about 1.5-2 km in length and caused strong steam plumes due to their interaction with a glacier. On 3 February, material from intense Strombolian activity was propelled 500 m above the crater floor and fell inside and outside of the crater. Multiple lava flows from the W edge of the main crater descended about 150 m. Incandescent blocks from lava-flow fronts rolled down the flank. Plumes rose to an approximate altitude of 4.6 km (15,100 ft) a.s.l. and drifted WNW. Lava flows originating from a lava lake were observed during an overflight. These flows extended about 1.5-2 km in length and caused strong steam plumes due to their interaction with a glacier. According to a news article, about 20 people were evacuated from an area of La Selva, in the community of Vilcún (43 km W). Activity was similar on 4 February. A phreatic explosion on the E flank was accompanied by steam plumes and a small pyroclastic flow. Orange ash emissions were noted from the S lateral fissure. Ash plumes from the main crater rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted E. Based on pilot observations, the Buenos Aires VAAC reported that ash plumes rose to altitudes of 4.6-6.7 km (15,000-22,000 ft) a.s.l. and drifted SE, NE, and W during 5-6 February. As of the 24th January, SERNAGEOMIN reported that eruptive activity at Llaima continued from the main crater and from two craters and a fissure on the E flank during 16-21 January. Based on observations during an overflight on 16 January, three nested pyroclastic cones within the main crater were active. The larger cone produced weak ash emissions that rose about 500 m. Ash emissions were also noted from a crater on the E flank. Glaciers on the NE slope and W flank were fractured and dislocated. Ash emissions from a NE-SW-trending fissure about 80 m in length and 10 m wide were observed. Also noted were incandescent rocks that rolled from the NE end of the fissure and ash plumes generated from rolling rocks in multiple areas during 16-17 January. On 17 January, ash emissions rose from the main crater to an altitude of 3.5 km (11,500 ft) a.s.l and drifted E. Weak Strombolian activity was seen from the main crater during aerial observation. of the 17th January, SERNAGEOMIN reported that seismicity from Llaima decreased in energy, but the number of events increased during 10-14 January. Based on seismic interpretation, weak explosions produced plumes of gas and ash. On 11 January, lava flows on the W flank that were observed during an overflight were cooled and snow-covered near the crater but snow-free, and therefore still hot, about 500 m further down on the flank. Blocks of incandescent material rolled about 1.5 km and caused steam emissions at several points where they contacted the glacier. Ash plumes drifted NE. Abundant cracks in glaciers to the SW of the crater were noted. Based on observations of satellite imagery and pilot reports, the Buenos Aires VAAC reported that ash plumes rose to an altitude of 5.5-6.7 km (18,000-22,000 ft) a.s.l. and drifted NE and SW on 11 and 13 January, respectively. s of the 4th January, INGEOMINAS reported that rescue workers evacuated 54 tourists and staff from a Chilean wilderness park on Wednesday after one of the country's largest volcanoes erupted, spewing ash and molten lava. There were no reports of injuries or damage, but dozens of tourists were evacuated from the base of the Llaima volcano after it erupted on Tuesday evening . The 54 people rescued had been stranded overnight after a local river swelled with meltwater and cut off road access. The volcano was calmer by Wednesday afternoon but according to scientists further eruptions were possible. As of the 2nd January, INGEOMINAS reported that Llaima volcano in southern Chile erupted on Tuesday, spewing lava and ash, and forcing the evacuation of about 150 people, officials said. Authorities declared an "early alert" around the Llaima volcano, readying police and firefighters in case further evacuations were needed, Chile's Emergency Bureau said in a communique. A column of smoke rose more than 9,300 feet into the sky and Swiss television images showed thick smoke and lava emerging from Llaima, one of the most active of the dozens of volcanos in Chile. Emergency bureau director Carmen Fernandez said 150 tourists and National Forest Service employees were evacuated from the Conguillio National Park where the volcano is located, 400 miles south of Santiago. If necessary, residents could also be evacuated from Melipeuco, a town of at least 5,000 located 8 miles from the volcano, officials said. Bureau officials and volcanologists were flying over the volcano to monitor the situation. The 9,400-foot volcano last erupted in May, but has not suffered a major blast since 1994. Llaima, one of Chile's largest and most active volcanoes, contains two historically active craters, one at the summit and the other, Pichillaima, to the SE. The massive 3125-m-high, dominantly basaltic-to-andesitic stratovolcano has a volume of 400 cu km. A Holocene edifice built primarily of accumulated lava flows was constructed over an 8-km-wide caldera that formed about 13,200 years ago, following the eruption of the 24 cu km Curacautín Ignimbrite. More than 40 scoria cones dot the volcano's flanks. Following the end of an explosive stage about 7200 years ago, construction of the present edifice began, characterized by strombolian, hawaiian, and infrequent subplinian eruptions. Frequent moderate explosive eruptions with occasional lava flows have been recorded since the 17th century.The Current Colour Code for Llaima is currently at RED . Llaima webcam

CHILE - Lascar volcano

November 22nd, 2007

As of the 21st of November, based on Significant Meteorological Information (SIGMET) advisories, the Buenos Aires VAAC reported that an eruption plume from Villarrica rose to an altitude of 3.8 km (12,500 ft) a.s.l. and drifted E on 14 November. Ash was not detected on satellite imagery. As of the 16th of March, the Gobal Volcanism Network (GVN) has notified and confirmed the eruption of the Lascar volcano. Previous news from the Buenos Aires VAAC reported that on 11 March an ash cloud from Lascar rose to 5.5-6.7 km (18,000-22,000 ft) a.s.l. and drifted E. Previous notable activity occured on 22nd of April 2006 when the Buenos Aires VAAC reported that Lascar volcano, located in the Central Andes of Northern Chile (23º22'/67º44'W) started an new eruptive cycle on April 18th 2006 at 1135 hrs (all are local times). Four explosions were recorded on the 18th, one rose up to 3,000 m above the active crater. Two explosive cycles were observed on the 19th starting at 1120 hrs and 1321 hrs, the second being the largest rising up to 800 m above the crater. The plume, which essentially consisted in gases with little ash, was dispersed towards the north. Fine ash fell on the northern upper flank of the volcano within a radius of 3 km. Two new explosive cycles were observed on April 20th starting at 1105 and 1339 hrs. The latter has been the longer observed so far, lasting 1 hour and 53 minutes. The plume consisted mainly of gases and little ash, rising up to 2500 m above the crater and dispersed towards the N at the beginning and at the end of the cycle towards the NE. Fine ash was deposited on the upper northern and eastern flanks. Finally two new, but smaller, explosive cycles were observed today starting at 0848 hrs and 1142 hrs, lasting less than 15 minutes each, with an eruptive column rising up to 3000 m above the crater, similar to those of the previous day, but dispersed towards the west and SW, respectively. These phreatic explosions show an unusual behavior of the volcano, and there is no evidence so far of new magma reaching the surface. Preliminary seismic data obtained by the Chilean Emergency Office (ONEMI) show only seismic events related to shallow degassing, without any seismic event associated to deeper fractures or magma movements. The largest eruption of Lascar took place about 26,500 years ago, and following the eruption of the Tumbres scoria flow about 9000 years ago, activity shifted back to the eastern edifice, where three overlapping craters were formed. Frequent small-to-moderate explosive eruptions have been recorded from Lascar in historical time since the mid-19th century, along with periodic larger eruptions that produced ashfall hundreds of kilometers away from the volcano. The largest historical eruption of Lascar took place in 1993 and produced pyroclastic flows that extended up to 8.5 km NW of the summit. A large eruption of Lascar volcano occurred in 1993 when pyroclastic flows reached 8.5 km from the summit

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JAPAN - Suwanose-jima volcano

April 25th, 2008

As of the 24th of April, the Global Volcanism Network (GVN) reported that based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-Jima occurred on the 16th of April. The altitude and direction of a possible resultant plume were not reported Based on information from JMA, the Tokyo VAAC reported that an explosion from Suwanose-jima occurred on 22 March. The altitude and direction of a possible resultant plume were not reported.As of the 14th of February, The Japan Meteorological Agency (JMA) via the Tokyo Volcanic Ash Advisory Centre (TVAAC) reported that Suwanose-Jima again exploded at 0208hrs ash cloud unknown observed ash date/time: Niil . Observed ash cloud: In investigating satellite data, winds are above the volcano at 0200Z at 10,000 ft. and at 30,000 ft., 39.1 mph. As of the 8th of February, JMA via the Tokyo Volcanic Ash Advisory Centre (TVAAC) reported that Suwanose-JIma has erupted again on the 7th of February. The eruption exploded at 0655Z to more than 4,000 ft. extended E observed ash cloud: in investigating satellite data the winds are above the volcano. At 0650Z they are at 10,000-30,000 ft. at 37.95 mph and at 20,000-27,000 ft. it is 65 mph. Based on information from JMA, the Tokyo VAAC reported that eruption plumes from Suwanose-jima also rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. on 10 December and drifted W. Ash was not visible on satellite imagery. 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 E 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 (also called Otake), 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.(JMA)

JAPAN - Sakurajima volcano

April 25th, 2008

As of the 24th of April, the Global Volcanism Network (GVN) reported that based on pilot reports and observations of satellite imagery, the Tokyo VAAC reported that an ash plume from Sakura-Jima rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted 100 km E on 19 April. The next day, the JMA reported that a plume rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted SW. Sakura-Jima first erupted in 2008 on the 6th of January. Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima during 11-15 April produced plumes that rose to altitudes of 2.1-3.4 km (7,000-11,000 ft) a.s.l. and drifted SW, NE, and SE. As of the 7th of February, JMA via the Tokyo Volcanic Ash Advisory Centre (TVAAC) reported that the volcano continued its eruption. Ash cloud: in investigating satellite data. Winds are above the volcano at0220Z at 10,000 ft. and at 26,000 ft at 56.35 mph and at 20,000 ft. at 63.25 mph. Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima on 3 February produced plumes that rose to altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted SE. Ash was not detected on satellite imagery. On 5 February, a pilot reported an ash plume at an altitude of 2.1 km (7,000 ft) a.s.l. As of the 8th of January, The Japan Meteorological Agency (JMA) reported that Sakura-Jima exploded at 1837UTC on the 6th of January but the ash cloud direction and height is unknown at this time. Officials are currently investigating satellite data. Later however, winds were found to be above the volcano at 1830 UTC it was at 10,000ft and at 20,000ft at 57.5 mph and at 40,000ft at 50.65 mph. Geologic Summary. Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Sakurajima webcam

JAPAN - Myakejima volcano

January 9th, 2008

As of the 8th of January, The Japan Meteorological Agency (JMA) via the Tokyo Volcanic Ash Advisory Center reported that Miyake-Jima exploded at 2154UTC on the 6th of January and the ash cloud was at a height of 4,000ft to the southeast. Officials are currently investigating satellite data. However, winds are above the volcano at 2154UTC it was at 4,000ft and at about 18.4 mph. Further details on this eruption will be published as they are received. The circular, 8-km-wide island of Miyake-Jima forms a low-angle stratovolcano that rises about 1100 m from the sea floor in the northern Izu Islands about 200 km SSW of Tokyo. The basaltic volcano is truncated by small summit calderas, one of which, 3.5 km wide, was formed during a major eruption about 2500 years ago. Parasitic craters and vents, including maars near the coast and radially oriented fissure vents, dot the flanks of the volcano. Frequent historical eruptions have occurred since 1085 AD at vents ranging from the summit to below sea level, causing much damage on this small populated island. After a three-century-long hiatus ending in 1469, activity has been dominated by flank fissure eruptions sometimes accompanied by minor summit eruptions. A 1.6-km-wide summit caldera was slowly formed by subsidence during an eruption in 2000; by October of that year the crater floor had dropped to only 230 m above sea level. A fieldtrip on this volcano was carried out during the COV5 meeting

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USA - Kilauea volcano ( Hawaian islands)

May 9th , 2008

A s of the 9th of May, it has been reported from the Hawaiian Volcano Observatory (HVO), that Kilauea Volcano is active at two locations. At the summit, production of small amounts of ash, elevated sulfur dioxide, and elevated seismic tremor continued from the Halema`uma`u vent. At the east rift eruption site, lava flowed through tubes to the ocean. L ast 24 hours at Kilauea summit: Molten lava may reside at shallow depth within the new vent. A white plume continued to issue from the vent in Halemaumau Crater and was being blown southwesterly. Small amounts of ash continue to be found each morning in collectors beneath the plume; this morning, the ash was wet from overnight rainfall. Overnight, the view of the vent was quite good before the fog rolled in. The SO 2 emission rate remained high; the most recent average measurement (May 7th) was 1,100 tonnes/day compared to a background rate between 150-200 tonnes/day. The summit tiltmeter network recorded weak deflation. Seismic tremor levels remained at elevated values. GPS receivers on opposite sides of the summit caldera recorded no extension or contraction above measurement error. Two earthquakes were located beneath the summit caldera, three on south flank faults, and one on the southwest seismic rift zone. As of the 25th of April, it has been reported from the Hawaiian Volcano Observatory (HVO), that Kilauea Volcano is still active at two locations. The current increase in sulfur dioxide emission rates at the summit means that SO2 concentrations in the air are likely to be at hazardous levels for areas downwind of emission sources in Halema`uma`u crater. On Wednesday, smoke and ash poured from the main crater of Kilauea volcano and elevated levels of sulfur dioxide from the volcano summit vent forced the evacuation of Hawaii Volcanoes National Park for the second time this month including Crater Rim Drive through the south caldera area until further notice. During tradewind conditions (brisk winds from the northeast), concentrations will be highest and most hazardous in the south caldera: southwest rift zone, south caldera pullouts, and the Halema`uma`u overlook parking lot. The gas plume also includes fine rock dust downwind of the source. During the past few days, several people have reported a fine grit on their car windshields while driving under or in the ash plume along highway 11. A small third explosion occured on 16th of April at 0400 AM from the summit Halemaumau crater vent. The most recent measurement was 970 tonnes/day on April 15, compared to a background rate between 150-200 tonnes/day. Seismic tremor levels remain elevated to several times background values with near regular variations in amplitude (called banded tremor). The summit tiltmeter network recorded no coherent signal. GPS receivers on opposite sides of the summit caldera recorded slow contraction. One earthquakes was located beneath the southwest rift zone. The second explosion from the new vent in Halema`uma`u Crater occurred at 11:08 p.m., H.s.t., on April 9, 2008. The explosion was smaller in magnitude than the one on March 19, 2008, but enlarged the vent by 5-10 meters (15-30 feet). USGS scientists, who have been monitoring Halema`uma`u around the clock, observed incandescent rocks being ejected from the vent during the explosion. Some blocks were blasted to the rim of the crater, about 70 m (230 feet) above the vent. They also noted that a faint glow returned to the vent a few minutes after the explosion. Other than explosion signals, no other geophysical changes accompanied the event. Shortly after dawn, Hawaiian Volcano Observatory geologists investigated the explosion debris on the crater rim above the vent. They found lava spatter and rocks, with one block measuring 35 by 21 by 20 cm (14 X 8 X 8 inches). The debris was apparently hot when ejected because fragments had melted plastic pans previously placed on the rim to collect ash. Based on field observations, last night's explosion ejected considerably less rocky material than the March 19 event. Hawai`i County Civil Defense received reports of ash fall in Pahala, suggesting that tiny fragments of rock pulverized by the explosion were carried down wind at least 19 miles. The Halema`uma`u vent continued to issue a white plume this morning. Returning trade winds are now blowing the plume to the southwest, which will allow scientists to measure sulfur dioxide gas emissions and ash production today. As of 8th of April, HVO informed that due to an elevated sulfur dioxide levels from Kilauea volcano and a change in wind direction Tuesday forced 2,000 people to leave Hawaii Volcanoes National Park on the Big Island. The park was closed, and those at campgrounds, the Kilauea Military Camp as well as the guests and staff at the 42-room Volcano House hotel were told to leave. . As of 24th of March, HVO reported that there was now continuous emission of ash from the new gas vent in Halema`uma`u Crater, turning the formerly white cloud of fume a dusty-brown color. The top of the ash plume, which is currently being blown to the southwest of the Crater, reaches 0.5 to 1.0 mile above ground level. Hawai`i aviation agencies have been notified of the potential hazard to aircraft. During the night, small incandescent particles were observed erupting from the vent below the Halema`uma`u Overlook. A few particles were ejected with sufficient velocity to be deposited on the rim of Halema`uma`u Crater. This morning, Hawaiian Volcano Observatory geologists reported finding Pele's hair, Pele's tears, and spatter in the overlook area, indicating that particles ejected overnight included molten lava-the first erupted from the new vent, which is now 30-35 m (100 ft) wide. The largest fragments of spatter, or blobs of molten rock, found on the crater rim are 10 cm (4 inches) in size. At 2:58 a.m. H.s.t on Wednesday, March 19, 2008, a small explosion occurred at Halema'uma'u Crater at the summit of Kîlauea Volcano in Hawai'i Volcanoes National Park. This event was erroneously reported as an earthquake earlier this morning. The explosion scattered debris over an area of about 30 Hectares), covering a portion of Crater Rim Drive and damaging the Halema'uma'u overlook. No lava was erupted as part of the explosion, suggesting that the activity was driven by hydrothermal or gas sources. In addition to damaging the overlook, explosive debris covers the trail to the overlook, the Halema'uma'u parking area, and the portion of Crater Rim Drive adjacent to the parking area. On Crater Rim Drive the debris was up to 2 centimeters in size, with the size and thickness of debris increasing toward the overlook. The largest observed block ejected during the explosion was about 1 cubic meter (35 cubic feet) and must have been propelled from the vent located more than 70 m (230 feet) below the crater rim. Small impact craters from 30 cm (1 foot) blocks are abundant in the Halema'uma'u overlook area. Rock debris also extends halfway across the floor of Halema'uma'u Crater. The debris is composed of rock fragments that were derived from the walls of Halema'uma'u Crater. No fresh lava was observed on the floor of Halema'uma'u or in the ejected debris. At 2:55 am, the Hawaiian Volcano Observatory recorded a series of seismic events that may have been shallow, high-frequency earthquakes or minor explosions. The main explosion at 2:58 was associated with long period seismicity. Low frequency sound waves were also detected by the University of Hawai`i infrasound laboratory, operated by Dr. Milton Garces. These signals have persisted through this morning indicating continuing energetic release of gas from the vent in Halema'uma'u Crater. The explosion produced a small crater along the east wall of Halema'uma'u that is about 20-30 meters (65-100 feet) in diameter. The crater occupies the area in which incandescence had been observed during the previous week. Sulfur dioxide emissions from the new explosion crater are still elevated, and sounds of rock breaking are frequent. This is the first explosion in Halema`uma`u crater since 1924 and the first eruption of any kind in Kîlauea caldera since September 1982. Future explosive activity is possible and the Hawaiian Volcano Observatory continues to monitor the activity. Photos, text updates, a new Halema`uma`u crater webcam, and details about the Kilauea 1924 explosive eruption can be found at the HVO website. As of 13th of March HVO reported that prominent new gas vent broke through the lower east wall of Halema‘uma‘u this week, doubling the already elevated level of sulfur dioxide gas being emitted from the crater. According to some observers, the new Halemaumau crater gas vent displayed dull red incandescence during following overnight The rate at which sulfur dioxide (SO2) is released by Kilauea volcano has typically been 150-200 tonnes/day, but in late December 2007, the emission rate increased to nearly 300 tonnes/day. This rate continued to rise into the new year, and by mid-February 2008, it fluctuated between 600 and 1000 tonnes/day. On March 12, the rate abruptly jumped to 1,500 tonnes/day. The following day, SO2 emission rates reached the highest recorded at Kilauea's summit since measurements began in 1979—from 1,800 to 2,000 tonnes/day. With increased emission rates, the concentration of noxious sulfur dioxide gas in the air, the cause of respiratory hazards, also rises. When the emission rate doubled in December 2007, sulfur dioxide concentrations exceeded 1 ppm on more than half of Crater Rim Drive between the Southwest Rift Zone pullout and the Halema‘uma‘u Overlook parking lot. From HVO - Near real-time web cam Pu'u'O'o.

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U.S.A. - Mauna Loa ( Hawaii)

March 29th, 2008

As of the 27th of April, the Hawaiian Volcano Observatory (HVO) has reported extension has has resumed after a hiatus of a few weeks. The network of continuous GPS receivers recorded extension in the past week. Tiltmeters have recorded no significant changes. Gas sensors continued to record background gas concentrations within a crack in the crater floor; the fumarole temperature decreased a little more than 3 degrees C since the beginning of February. Over the past 6 months, our GPS network has recorded nearly 1 cm of extension across the caldera and 2 cm of extension across the flanks. Beginning around December 1, 2006, extension slowed further but resumed pre-December rates by mid month. Slow inflation continues. Tiltmeters have recorded no significant changes. Mauna Loa remains seismically quiet with few earthquakes occurring beneath the summit and the Ka`oiki seismic zone on the east flank. Since the beginning of January, 2005, HVO analysts have rarely located more than 10 earthquakes per week beneath Mauna Loa summit. Of the located earthquakes, less than a handful are Long-period in nature. Network status: -two tiltmeters are down, five are working properly; -GPS network is working properly; -seismic network is working properly; -gas sensors are not working properly. The colour code at Mauna Loa is currently at YELLOW.

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USA - Veniaminoff volcano (Alaska)

April 25th , 2008

As of the 25th of April, the Alaska Volcano Observatory (AVO) has reported that seismic activity shows that seismic data show that low level volcanic unrest continues at Mt. Veniaminof volcano. Clear web cam views of Mt. Veniaminof volcano show light steaming continues. No activity was observed in mostly clear satellite views. AVO will continue to monitor activity at Mt. Veniaminof using seismic data, satellite images, internet camera data and observer reports. 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 3700 years ago. The caldera rim is up to 520 m high on the north, is deeply notched on the west by Cone Glacier, and is covered by an ice sheet on the south. 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 2156 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.

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U.S.A. - Augustine volcano

October 13th, 2007

As of the 12th of October, the Alaska Volcano Observatory (AVO) has reported that again shallow, low-level activity continues. Clear satellite views showed nothing unusual; webcam views were cloudy. AVO continues to monitor Augustine Volcano closely. Detected earthquakes could cause some disruption of the 2006 summit lava dome. Small rock avalanches could occur on the flanks of the volcano. Mt. 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

USA - Mount Cleveland volcano (Aleutian islands)

May 9th, 2008

A s of the 9th of May, the Alaska Volcano Obsetrvatory (AVO) reported that last night, a small, low-altitude (less than 15,000ft) ash cloud was observed in satellite images from 1600hrs AKDT, May 7th (0000UTC, May 8th) until about 2300hrs AKDT, May 7th (0700UTC, May 8th). A ship north of Nikolski reported light ashfall occurring about 2000hrs AKDT. No other ash clouds have been observed. No new thermal activity was observed at Cleveland, though the current conditions are very cloudy. AVO monitors Mt. Cleveland volcano with satellite imagery as weather allows. The lack of a real-time seismic network at Mt. Cleveland means that AVO is unable to track local earthquake activity related to volcanic unrest. Short-lived explosions of ash that could exceed 20,000 ft above sea level can occur without warning and may go undetected on satellite imagery. Two pilots reported an eruption of Mt. Cleveland volcano in Alaska at 1630 hr, local time, on Friday, the 8th of February. Ash reached 20,000 ft and drifted NW. A diffuse low-level plume was observed earlier in satellite images. There is no seismic monitoring at the volcano. Mt. Cleveland volcano had one eruption in 2007, and four in 2006. A possible thermal anomaly was observed in satellite imagery last night. No other activity was reported. AVO monitors Mt. Cleveland volcano with satellite imagery as weather allows. The lack of a real-time seismic network at Mt. Cleveland means that AVO is unable to track local earthquake activity related to volcanic unrest. Short-lived explosions of ash that could exceed 20,000 ft above sea level can occur without warning and may go undetected on satellite imagery. Beautifully symmetrical Mt. Cleveland stratovolcano is situated at the western end of the uninhabited, dumbbell-shaped Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Cleveland is joined to the rest of Chuginadak Island by a low isthmus. The 1730-m-high Mt. Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands.

U.S.A. Pavlof volcano (Alaska)

September 22nd, 2007

As of the 21st of September, the Alaska Volcano Observatory (AVO) has reported that seismic activity at Pavlof Volcano declined significantly last week and remains at a low level. AVO has lowered the Aviation color code to YELLOW and the Volcano Alert Level to Advisory. An AVO field crew at the volcano yesterday afternoon observed that all eruptive activity has ceased. The decrease in seismicity and cessation of eruptive activity may be only a lull in the current eruption. Typical eruptions at Pavlof are characterised by periods of diminished activity interspersed with periods of renewed eruptive activity that can begin at any time with little seismic warning. AVO will continue to monitor the volcano closely. Rockfall from the unstable front of the lava flow remains a hazard on the southeast flank of the volcano and small dust/ash plumes could be generated but are not likely to rise above the summit of the volcano. Small lahars could be generated down drainages below the lava flow should hot rockfall debris contact snow and ice. Previous historical eruptions from Pavlof caused only a few millimeters (about 1/10th of an inch) of ash to fall on King Cove, Nelson Lagoon, Cold Bay, and Sand Point. Mudflows in drainages from the flanks of the volcano, and lava flows and avalanching of hot debris on the upper reaches of the volcano are also of concern in the uninhabited areas around the volcano. Satellite and seismic data and eyewitness observations suggest most of the surface lava activity is occurring on the southeast sector of the steep-sided volcano; this suggests that the Pacific Ocean side of the volcano is at most risk from avalanching hot debris.

U.S.A. - Mount St.Helens

March 10th, 2008

As of the 9th of March, the Cascades Volcano Observatory (CVO) reported that the pause in lava dome growth continues, and all our monitoring instruments show trifling or nil volcanic-related activity. This pause, which began in late January 2008, was recognized by absence of measurable growth among successive fixed-camera images, nearly quiescent seismicity, and the absence of tilt signals that might characterize extrusion of lava from the conduit. CVO continues to monitor closely for evidence of renewed extrusion or other activity. The new lava dome remains hot in places; thus, it is capable of producing hot avalanches or small steam explosions that could cause hazardous conditions in and around the crater. Sudden melting of snow and ice could send small lahars onto the Pumice Plain and perhaps down the Toutle River as far as the Sediment Retention Structure (SRS). Ash clouds from explosions could affect aircraft. Recent Observations: There was no field work done at Mt. St. Helens this week. The most significant development was a small, magnitude-2.0 earthquake on Tuesday at 1131hrs, and very small earthquake swarm on Thursday, starting with a roughly magnitude 1.2 event at 1416hrs and followed by several smaller events over a seven-minute period. There were no tilt changes assocaited with this swarm. Previous activity : as of the 9th of March 2007, the Cascades Volcano Observatory (CVO) was reported that on 8th of March a small explosive event at Mt. St. Helens volcano began at approximately 5:25 p.m. PST one hour after a magnitude 2.0 volcanic earthquake was registered under the volcano. Pilot reports indicate that the resulting steam-and-ash plume reached an altitude of about 36,000 feet above sea level within a few minutes and drifted downwind to the east-northeast. The principal event lasted about 30 minutes with intensity gradually declining throughout. The USGS Cascades Volcano Observatory lost radio signals from three monitoring stations in the crater soon after the event started. The cause of the outage won’t be known until scientists can visit the crater tomorrow to assess the situation, weather permitting. The event followed a few hours of slightly increased earthquake activity that was noted but not interpreted as precursory activity. The main part of the eruption lasted 30 minutes. Three monitoring stations in the crater have stopped operating, and will be checked by scientists when conditions permit. There were no other indications of an imminent change in activity. During 21-26 October, the new lava dome inside the emerging dome of St Helens continued to grow, and seismicity remained at low levels compared to early in the unrest. Geological and thermal-imaging observations on 20 October confirmed that both the area of uplift, and the new lava extrusion increased in size noticeably since last seen on 14 October. In addition, the area of uplift and intense deformation continued to move southward and was nearing the crater wall. About 0.3 m of new snow with a light dusting of ash covered much of the uplift, except for the new lava extrusion, which was steaming heavily. The new lava extrusion, which occupies the western part of the uplift, was about 275 m long by 75 m wide, 70 m high, and had a volume of almost 1.5 million cubic meters. Its maximum temperature was about 600 degrees C. Low levels of carbon dioxide, sulfur dioxide, and hydrogen sulfide were recorded on the 20th, an observation which did not rule out the continued rise of magma from depth. On 21 October a new protrusion had a maximum temperature of about 650 degrees C. As of the 11th of October, CVO reported that earthquakes continue to occur at a rate of about 1 per minute, but most have magnitudes of 1.0 or less. With the improving weather, a gas measuring flight is planned within the next two days. Additional analysis of lidar and photographs of the intensely uplifting area on the south side of the lava dome suggests that the total volume change represented by the deformation between late September and October 6 is about 16 million cubic meters (21 million cubic yards). The average rate of change is about 2 million cubic meters per day (2.6 million cubic yards per day). If this figure represents the rate of intrusion of magma into shallow levels of the dome and(or) underlying crater floor, it is an intrusion rate about twice that measured during dome-building eruptions at Mount St. Helens in the 1980s. Cartographers with the USGS office in Denver are working to develop precise volume change estimates for the uplifted area from stereo airphotos acquired between 1 and 5 October. As a result of the intense unrest of the past 17 days, we infer that magma is at a very shallow level. During times of unrest, Mt. St. Helens and similar volcanoes elsewhere typically go through episodic changes in level of unrest over periods of days to weeks, or even months. Such changes are in part driven by variations in the rate of magma movement. CVO expects fluctuations in the level of unrest to continue during coming days. Escalation in the degree of unrest and perhaps an eruption could occur suddenly or with very little warning. There may be little time to raise the alert level before a hazardous event occurs. Therefore, CVO continues to monitor the situation closely and will issue additional updates and changes in alert level as warranted. As of the 8th of October, the Cascades Volcano Observatory (CVO) reported that part of the lava dome in Mt. St. Helens' crater has risen 50 to 100 feet since Tuesday while earthquake activity remained lower than previous days. This indicates magma is moving upward without much resistance. The south side of the dome has been rising for the past week and has uplifted 250 ft. A new steam vent opened overnight of 6th-7th October, and joined the two that have been present for several days. Steaming from the vents generated a cloud rising above the south side of the lava dome. October 6th update : Following yesterday morning’s steam-and-ash eruption, seismicity dropped to a low level and has remained low. Low-level tremor observed following the eruption is also gradually declining. Lack of earthquake and rockfall signals suggest that deformation of the uplift area on the south side of the 1980-86 lava dome has slowed. Brief visual observations this morning from Coldwater Visitor Center showed weak steam emissions from the crater. We infer that the vigorous unrest of the past few days has lessened and that the probability of an imminent eruption that would endanger life and property is significantly less than at any time since Saturday, October 2, when the alert level was raised to Volcano Alert (Level 3). Therefore, we are lowering the alert level to Volcano Advisory (Alert Level 2).New steam release began at 9:40 am PDT yesterday, October 4, 2003, generating a steam and ash/dust plume that rose above the summit (to about 10,000 to 11,000 feet altitude) and was carried slowly to the NE by very gentle winds. Steam releases continued at a lower rate after the initial release, but after 15-20 muntes the activity ceased. More dust/ash was released than on October 1, and an ashfall advisory is in effect until 1 pm PDT for the southern Washington Cascades. Seismicity continued without interruption through the steam release. As of 3rd of October CVO reported at 2 pm , CVO increased the alert level to Volcano Alert due to a change in the character of seismic signals (50 minute long tremor) that occurred immediately after a steam emission at 1216, recognition of ongoing uplift of the crater floor, and reports of sulfur gas odor. In addition, CVO believes that there is a significantly increased probability that gas-rich magma is moving toward the surface. After another period of tremor starting 4th of October at 0257 AM seismicity returned to discrete earthquakes. Seismic activity decreased gradually until about 2:00 P.M. then increased again, reaching levels comparable to those prior to steam and ash eruptions. M3 earthquakes are occurring at a rate of about one every 5 minutes. All earthquake locations remain shallow. Yesterday’s gas sensing flights detected significant concentrations of carbon dioxide north and west of the dome. No significant levels of sulfur gasses were detected. Hydrogen sulfide (H2S)odors detected by helicopter crews are attributed to steam emissions. These low levels of hydrogen sulfide are likely the result of boiling of the hydrothermal system. Results from GPS measurements indicate no significant deformation of the outer flanks of the volcano. However, visual observations and photographic analysis show large-scale uplift (10’s of meters) of part of the glacier and a nearby segment of the south