Volcanoes

[Shammu]

KLIUCHEVSKOI

As of the 4th of June, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that explosive-effusive eruption of the volcano continues. Ash explosions >7.0 km (>23,000 ft) ASL could occur at any time. The activity of the volcano could affect international and low-flying aircraft. Seismicity of the volcano was above background levels all week. According to visual data, Strombolian activity of the volcano continues. Moderate gas-steam activity with bursts of small amount of ash was observing all week. Ash columns rose up to 7.25 km (23,780 ft) ASL on June 1st. According to satellite data, a big thermal anomaly was registering over the volcano all week. Ash plumes extending about 40 km (25 mi) to the north-west from the volcano were noted on May 28th and 31st.

Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 6000 years ago, the beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. Kliuchevskoi rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred at Kliuchevskoi during the past roughly 3000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m elevation. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.

The Current Colour Code for Kliuchevskoi is ORANGE
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NEVADO del HUILA

As of the 3rd of June, the the Observatory Vulcanológico and Sismológico de Popayan (INGEOMINAS) reports that in the present week 260 seismic events was registered. Of them, 29 were related to fracturing of rock (Type VT) and 225 with the dynamics of flowed within the volcanic conduits; of these last ones, 182 correspond to transit of gases and flowed (Type LP), 6 events to conjugated phenomena of fractuing of rock and dynamics of flowed (Hybrid Type) and 43 pulses of tremor of low magnitude. During the week it was observed through the satelite images published by international agency NOAA (National Oceanic and Atmospheric Administration), emissions of SO2  to the atmosphere on the 27th, 28th and 31st of May. Of equal way, values of flow between 1900 and 3100 have attracted columns of SO2  by means of the station of ScanDOAS installed in Cali, calculating tonnes/day. The 30th of May were realised in a fly over of superficial recognition to the area of influence of the volcano, with the support of the Colombian Air Force (FACE), being observed that they continue the degassing processes around the crater and to the north of the central tip, in columns that do not surpass the 1000 m of height, with preferential dispersion made the east, according to the prevailing wind regime in the zone. During the week it was observed that the volcano presented/displayed a stable behaviour, with predominance of the associated seismicity processes of movement and transit of flowed within the internal conduits, phenomenon related possibly to the extrusion of magmatic material.

Nevado del Huila, the highest active volcano in Colombia, is an elongated N-S-trending volcanic chain mantled by a glacier icecap. The 5364-m-high andesitic-dacitic volcano was constructed within a 10-km-wide caldera. Volcanism at Nevado del Huila has produced six volcanic cones whose ages in general migrated from south to north. The high point of the complex is Pico Central. Two glacier-free lava domes lie at the southern end of the Huila volcanic complex. The first historical eruption from this little known volcano was an explosive eruption in the mid-16th century. Long-term, persistent steam columns had risen from Pico Central prior to the next eruption in 2007, when explosive activity was accompanied by damaging mudflows.

The Current Colour Code for Nevado del Huila is YELLOW
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PACAYA

As of the 5th of June, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that in just the past seven days, residents of Guatemala and parts of neighbouring Honduras and El Salvador have had to cope with a volcanic eruption and ash fall, a powerful tropical storm, the resulting floods and landslides, and a frightening sinkhole in Guatemala City that swallowed up a small building and an intersection. Pacaya volcano started erupting lava and rocks on May 27th, blanketing Guatemala City with ash, closing the airport, and killing one television reporter who was near the eruption. Two days later, as Guatemalans worked to clear the ash, Tropical Storm Agatha made landfall bringing heavy rains that washed away bridges, filled some villages with mud, and somehow triggered the giant sinkhole - the exact cause is still being studied.

Atmospheric conditions: Partially Dimmed. Winds: North to 32 km/h. Pluvial precipitation: 40.9 mm Activity: In the last hours the seismic activity has been increased. This associate to a refeeding of the lava flows, where today 15 flows in southwestern direction are observed, with lengths of 300, 500, 800, 1600 metres. One of them this patch to the Cerro Chino, which this causing small fires to its step. In the Mackenney crater moderate fumaroles in a South direction, southwestern of 500 metres of height is observed, the explosions of estromboliano type expel weak amount from ash to 20, 25 metres of height accompanied by little pyroclastic material that is deposited within the crater and will be forming crater an Inter cone in the next days. RECOMMENDATION to CONRED and the authorities of NATIONAL PARK PACAYA, to restrict the access to the neighbourhoods of the lava flows, due to the abundant lava effusion in the southwestern flank and to take into account that the constant accumulation of material can generate avalanches of blocks in the zone.

The eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlán caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19th century. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the cone.

The Current Colour Code for Pacaya is ORANGE

[Shammu]

POPOCATEPETL

As of the 7th of June, CENAPRED has reported that in the last 24 hours, the monitoring system of Popocatepetl volcano recorded 22 low intensity exhalations, accompanied by steam and gas emissions. The other monitored parameters remain without important changes. At the moment of this report CENAPRED can see the volcano with a steam and gas emission. The traffic light of volcanic alert is in YELLOW phase 2. 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.

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

The Current Colour Code for Popocatepetl is YELLOW
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REVENTADOR

As of the 6th of June, the Instituto Geofísico-Escuela Politécnica Nacional (IG) has reported that the seismic activity remains in moderate levels, similar to the previous days. The volcano is cloudy but it has not generated rains.

A total of 19 Long Period (LP) events, 4 explosions, 8 episodes of spasmodic tremor and 1 episode of harmonic tremor has been entered.

Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well E of the principal volcanic axis. It is a forested stratovolcano that rises above the remote jungles of the western Amazon basin. A 3-km-wide caldera breached to the E was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1,300 m above the caldera floor. Reventador has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera.

The Current Colour Code for Reventador is ORANGE
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RINJANI

As of the 27th of May, the Volcanological Society of Indonesia (VSI) has reported that according to news articles, three eruptions from Rinjani during the 22nd-23rd of May were accompanied by tremors. Ash and incandescent material was ejected as high as 2 km. Ash plumes drifted 12 km and caused ashfall in multiple areas. Lava flowed into the caldera lake and caused the lake water temperature to rise from 21 to 35 degrees Celsius.

The Current Colour Code for Rinjani is ORANGE 2

[Shammu]

SAKURA-JIMA

As of the 27th of May, the Global Volcanism Network (GVN) has reported that based on information from JMA, the Tokyo VAAC reported that on the 21st of May an explosion from Sakura-Jima produced a plume that rose to an altitude higher than 2.1 km (7,000 ft) a.s.l.

Sakura-Jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-Jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.

The Current Colour Code for Sakura-Jima is ORANGE
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SANGAY

As of the 13th of May, the Global Volcanism Network (GVN) has reported that the Washington VAAC reported that on the 6th of May an ash plume from Sangay was seen by a pilot. Ash was not identified in satellite imagery, but a diffuse steam-and-gas plume was seen before weather clouds moved into the area.

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

The Current Colour Code for Sangay is ORANGE
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SANTA MARIA

As of the 5th of June, the National Institute Of Sismología, Volcanology, Meteorology And Hidrologia, (INSIVUMEH) has reported that Atmospheric conditions: Dimmed. Winds: of the North in calm. Pluvial precipitation: 18.0 mm Activity: Without direct visibility. Explosions, sounds by degassing or avalanches in the lava flows are not reported.

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

The Current Colour Code for Santa Maria is ORANGE

[Shammu]

SARIGAN

As of the 5th of June, the U.S. Geological Survey (USGS) has reported that an explosive eruption from a submarine vent south of Sarigan Island occurred on May 28th-29th. The most energetic phase of the eruption (1147 hrs UTC on May 29th) was brief, lasting about 10 minutes based on seismic records on adjacent Sarigan and Anatahan Islands, sending an ash and gas cloud perhaps as high as 40,000 ft above sea level. The eruption was preceded by two moderate earthquakes and many smaller shocks; a moderate earthquake of magnitude approximately 4.8 accompanied the eruption. The eruption cloud drifted to the south, eventually passing over Guam, but no fallout was reported on Guam or Saipan. Following the short-lived explosion, activity appears to have ceased.

Evidence of submarine volcanic activity was first observed late on May 28th during aerial observations by a Commonwealth of the Northern Mariana Islands (CNMI) Emergency Management Office (EMO) technician who noted an elongate patch of discoloured ocean water and possible light-coloured floating debris about 5 miles south of Sarigan Island. AVO seismologists noted tremor on nearby seismic stations about the same time. On May 29th, satellite image analysis by the National Weather Service in Guam indicated that the area of disturbance had grown significantly in size prior to the 1147 hrs UTC explosion. Within hours of the eruption, seismic activity began to wane, and after May 31st, only a few scattered seismic events continue to be recorded. The exact location of the active vent is still uncertain. The most likely source is the general summit area of a conical volcanic seamount located about 7 miles south of Sarigan Island.

A U.S. Fish and Wildlife Service research crew camped on Sarigan Island during the eruption reported many felt earthquakes prior to the eruption and an explosion like 'thunder' accompanying the event. They also heard increasing wave activity during the night that may have been associated with the eruption; subsequently, a minor ash fall occurred. The NOAA West Coast and Alaska Tsunami Warning Center reported a possible 2-inch high tsunami related to this event may have been recorded on a tide gauge in Saipan. Submarine eruptions are not uncommon in the Mariana Islands. While this event appears to have abated for now, mariners in the area should remain alert for floating debris and avoid areas of strongly discoloured or disturbed water. Near-sea level eruptions can be dangerous producing ash laden explosions, ash and ballistic fallout, and water waves. AVO maintains no monitoring equipment on these submarine volcanoes and therefore warning of eruptive activity is not possible. Following the eruption of a submarine vent south of Sarigan Island, the CNMI Emergency Management Office restricted access to all of the Northern Mariana Islands.

The Sarigan volcano forms a 3-km-long, roughly triangular island. A low truncated cone with a 750-m-wide summit crater contains a small ash cone. The youngest eruptions produced two lava domes from vents above and near the south crater rim. Lava flows from each dome reached the coast and extended out to sea, forming irregular shorelines. The northern flow overtopped the crater rim on the north and NW sides. The sparse vegetation on the flows indicates they are of Holocene age (Meijer and Reagan, 1981).

The Current Colour Code for Sarigan is YELLOW
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SHEVELUCH

As of the 4th of June, the Kamchatkan Volcanic Eruption Response Team (KVERT) reported that explosive-extrusive eruption of the volcano continues. Ash explosions >10 km (>32,800 ft) ASL could occur at any time. The activity of the volcano could affect international and low-flying aircraft. Seismicity was above background levels all week. According to seismic data, possibly ash plumes rose up to 6.1 km (20,010 ft) ASL all week. According to visual data, ash plumes rose up to 4.5 km (14,800 ft) ASL all week, strong fumarolic activity was observed all week. Hot avalanches were noting in the dark time. According to satellite data, a big thermal anomaly was registering over the lava dome all week. An ash cloud 20x6 km in size was detected in ~15 km (9 mi) to the north from the dome on May 31st. Gas-steam plumes extended about 30 km (19 mi) to the west from the volcano on May 29th.

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

The Current Colour Code for Sheveluch is ORANGE
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SOUFRIERE HILLS

As of the 5th of June, the Monstserrat Volcano Observatory (MVO) reported that activity at the Soufrière Hills volcano has been low this week. There were 16 rockfall signals, 1 long-period earthquake and 6 volcano-tectonic earthquakes. The average sulphur dioxide flux was 235 tonnes per day, with a minimum of 200 and a maximum of 266. This is probably an under-estimate of the true flux, as the plume was blown towards the north for much of the week, close to the edge of the coverage of the gas sensors, and it was only possible to obtain measurements for three days. Residents may have observed some very light ashfall caused by rockfalls as well as volcanic smells when the wind has been towards the north. There has been a noticeable atmospheric haze around Montserrat. This is not related to the volcano and is caused by Saharan dust blown across the Atlantic. Helicopter observations showed no major changes to the lava dome. The Hazard Level is 3. There is no access to the terrestrial Zone C and daytime transit access to shipping through the maritime extension of the zone.

The complex, dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. English's Crater, a 1-km-wide crater breached widely to the east, was formed during an eruption about 4000 years ago in which the summit collapsed, producing a large submarine debris avalanche. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits at Soufrière Hills. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but with the exception of a 17th-century eruption that produced the Castle Peak lava dome, no historical eruptions were recorded on Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.

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

[Shammu]

STROMBOLI

As of the 1st of April, the Global Volcanism Network (GVN) has reported that INGV-CT reported strong explosions from Stromboli, which started on the 10th of March, continues mainly from craters located in the N part of the crater terrace, a flat area in the upper part of Sciara del Fuoco (a depression cutting the NW flank of the volcano). After one of the more powerful explosions, lava flowed over the NW edge of the crater terrace for tens of metres before fragmenting and producing small landslides of hot material that likely reached the sea.

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

The Current Colour Code for Stromboli is ORANGE
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SUWANOSE-JIMA

As of the 20th of May, the Global Volcanism Network (GVN) has reported that based on information from JMA, the Tokyo VAAC reported that explosions from Suwanose-jima during the 15th-16th of May produced plumes that rose to altitudes of 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted N and NW.

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

The Current Colour Code for Suwanose-Jima is ORANGE
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TUNGURAHUA

As of the 6th of June, the Instituto Geofísico (IG) has reported that at the moment the volcano maintains an activity high. Average of 3 explosions per hour is had. The explosions generated strong cannon shots and roars (type exhalation), that expelled blocks to a height from 1 km on the level of the crater (snc) and later descend around 1.5 km under the level of the summit (bnc), besides steam columns with low content to means from ash and direction of the West and the Southwest. Ash fall is reported during this behind schedule in the sector of Chonglotus. Light rains in the western flank are registered those that did not generate lahars.

The IG reports that the period has registered 17 movements of long period (LP's), 79 Explosions, and 9 episodes of tremor of emission. Observations, Emissions and Ash: The volcano has remained dimmed most of time, nevertheless, between 0100 hrs (local time) until 0300 hrs (local time) today was sprightly and Strombolian activity was observed, characterized by explosions, that send to blocks up to 1 km, many of which they fall in flanks and they descend approximately 1.5 km under the summit. Additionally with the explosions perceived strong cannon shots in near zones are heard where they caused the vibration of glasses and doors; besides more distant sectors like the cities of Ambato, Riobamba, Patate, Penipe and Pelileo. Following the explosions one noticed episodes of tremor to which noises and roars were associated type exhalation of median to strong. Sometimes, between clouds it was possible to be observed volcanic gas and aqueous vapour emissions with low loads moderate of ash that went to the West and the Southwest of the volcano. It was received reports of fine ash falls of white colour along with drizzles in Chonglotus, during this behind schedule. Rains and Lahars: Light rains in all the western flank of the volcano without generating lahars or flows of mud were registered.

Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major volcanic edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II itself collapsed about 3000 years ago and produced a large debris-avalanche deposit and a horseshoe-shaped caldera open to the west, inside which the modern glacier-capped stratovolcano (Tungurahua III) was constructed. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. Prior to a long-term eruption beginning in 1999 that caused the temporary evacuation of the city of Baños at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925.

The official colour of the volcanic alarm light remains on ORANGE

[Shammu]

TURRIALBA

As of the 20th of May, OVSICORI-UNA reported that during April a majority of the gases emitted from Turrialba originated from the vent that opened in January, producing plumes that rose 2 km. Gas was emitted from other areas including from fissures SW of the W crater and from multiple vents and fissures in the main crater. Gas plumes mainly drifted NW, W, and SW, coincident with areas that had the most vegetation impact from the plumes.

Turrialba, which erupted on a small scale at the beginning of January, has returned to a state of "passive degassing" similar to that which pertained before the eruption, according to reports from Costa Rica. However, OVSICORI-UNA experts have warned that although activity has declined low intensity earthquakes continue, the volcano remains active and people should not be complacent. The Comisión Nacional de Emergencias (CNE) has revised the alert levels currently applied to the area surrounding the volcano, with Yellow Alert now applying to a 2 km radius zone around the volcano and Green Alert to areas beyond that limit (CNE news release: Alerta Verde y Alerta Amarilla ante Actividad Volcánica).

Levels of gas emission from Turrialba have fallen since the eruption but this volcano is a persistent and unpleasant degasser , and this aspect of its activity continues. In particular, the appearance of large amounts of helium in Turrialba's emissions has been attracting the attention of the experts. There's nothing official about this yet from Ovsicori, but the Costa Rican newspaper La Nación reports that the volcanologists could not believe what was happening when Jorge Andres Díaz, a physicist and gas measurement specialist working for the Comisión Nacional de Emergencias reported that measurements taken on the 19th of January indicated there was 30 ppm (parts per million) of helium in Turrialba's emissions:
For the volcanologists of the National Seismological Network and Ovsicori, that figure was much too "high", because normally helium at the volcano fluctuates between 2 and 8 ppm. "That would be way too much", says Raúl Mora, volcanologist at the [National Seismological] Network. The volcanologists and Díaz apparently got into a discussion lasting several hours about this at the CNE headquarters yesterday. However, the presence of high proportions of helium in gas emissions from Turrialba was noted back in April 2008 , when it was interpreted as being the result of magma build-up within the volcano. Measurements taken in March 2008, also by Díaz, indicated helium levels of 80 ppm. At that time, Ovsicori reported the normal level of helium for Turrialba as 25 ppm, which would make a possible level of 30 ppm now a bit less of a leap. In any case, the presence of elevated helium levels in Turrialba's emissions is an indicator that fresh magma is being intruded into the volcanic system.

Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive 3340-m-high Turrialba is exceeded in height only by Irazú, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE. Most activity at Turrialba originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred at Turrialba during the past 3500 years. Turrialba has been quiescent since a series of explosive eruptions during the 19th century that were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.

The official colour code for Turrialba is YELLOW
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ULAWUN

As of the 3rd of June, RVO reported that during the 22nd-28th of May, Ulawun emitted thick white vapour plumes that rose 800 m high. Some areas of the plumes were gray on the 22nd and 25th of May. People on the S and SE sides of the island heard "low jetting" noises during the 24t-25th of May. Weak and fluctuating incandescence was seen at night during the 28th-29th of May by people on the S part of the island. The emissions changed colour to gray on the 29th of May and continued similarly the next two days. On the 30th of May very fine ashfall was reported in areas to the SSW, S, and SSE. On the 1st and 2nd of June only white vapour emissions were noted. RVO recommended to the WNB Provincial Disaster Committee to declare a Stage 1 Alert to reflect an increasing trend of seismic energy, and a recent presence of occasional gray plumes, incandescence, and audible noises from Ulawun.

The symmetrical basaltic-to-andesitic Ulawun stratovolcano is the highest volcano of the Bismarck arc, and one of Papua New Guinea's most frequently active. Ulawun volcano, also known as the Father, rises above the north coast of the island of New Britain across a low saddle NE of Bamus volcano, the South Son. The upper 1000 m of the 2334-m-high Ulawun volcano is unvegetated. A prominent E-W-trending escarpment on the south may be the result of large-scale slumping. Satellitic cones occupy the NW and eastern flanks. A steep-walled valley cuts the NW side of Ulawun volcano, and a flank lava-flow complex lies to the south of this valley. Historical eruptions date back to the beginning of the 18th century. Twentieth-century eruptions were mildly explosive until 1967, but after 1970 several larger eruptions produced lava flows and basaltic pyroclastic flows, greatly modifying the summit crater.

The official colour of the volcanic alarm light is on ORANGE
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YASUR

As of the 6th of June, the Vanuatu Geohazards Observatory (VGO) reported that high level activity continues at Yasur volcano, Vanuatu. Explosive eruption have sent lava bombs several hundred metres from the crater. Ashfall is affecting areas surrounding the volcano and trade winds are blowing ash northwest towards middle bush. The eruptions have not disrupted flights in Vanuatu, although some domestic flights in New Caledonia have been affected.

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

The official colour of the volcanic alarm light is on ORANGE 3

[nChrist]

Thanks Brother Bob!

It's always fascinating to see what volcanic activity is around the world, knowing that any one of them could be a huge disaster. The effects of just one major eruption could have effects almost beyond imagination. Again, we know how disasters fit into the end times, and we know that man can cause his own disasters (i.e. oil spills). I think it is fair to say that these are signs of the times.