Weak strombolian activity continues at San Cristobal volcano; light ash fall was reported in the localities of Las Brisas, El Pellisco and Juan José Briceño.

Lava extrusion at Soufriere Hills volcano on Montserrat continues. Over the past week, dome growth has occurred over a sector extending from the south-west around to the north-east. The eastward-facing lobe has continued to grow on the northeast side of the dome and a central spine was observed on 28 April. Small rockfalls and pyroclastic flows continued to fall from the active eastern flanks of the dome, adding to the talus in the upper reaches of the Tar River valley. Rockfall activity has been accompanied by minor ash venting. Thermal images taken on 27 April indicated some very hot (in excess of 400 degrees centigrade) areas on the eastern flanks of the dome.

As the Jakarta Post reports, the Jambi provincial administration has warned residents on the slopes of Mt. Kerinci in West Sumatra to be on the alert due to the volcano's rising activity level. Kerinci has been increasingly active since October 2004, when it last had a small ash eruption.

Mount Merapi started to show first signs of fresh magmatic actiovity, erupting a small amount of ash on Friday 28 April 2006. The alert level remains at its second highest level and volcanologist think that a major eruption is possible in the near future.

Bulusan volcano erupted on Sat. 29 April 2006 at 10:44 am (0244 GMT) spewing a column of ash about 1.6 km high. Ash fall occurred in surrounding villages. There were no reports of casualties or damage.

Close-up into one of the holes with the branch sticking inside

Prof. Walter Friedrich when at the site

We are proud to announce a scientific discovery that has been made in close connection to one of our past tours on Santorini: A new absolute date for the great Minoan eruption on Santorini volcano has been published yesterday in the issue of Science Magazine (28 April, 2006). It confirms an early date for the eruption putting it at 1627-1600 BC with very good confidence.

As KVERT reports, strombolian-to-vulcanian activity continued at Karymsky during the past weeks. Satellite imagery showed ash plumes extending ~40-145 km E and SE of the volcano, and a large thermal anomaly at the volcano's crater. Karymsky remained at Concern Color Code Orange.

Over the past weeks, weak strombolian activity continued at Fuego volcano, ejecting incandescent material ~50-75 m high, and gas plumes to ~150-200 m above the volcano. Incandescent landslides traveled down the volcano's S and W flanks. Lava flowed ~400 m S towards Taniluyá ravine.

As of 13 April, seismicity at Raoul Island had returned to normal and Green Lake's water level was dropping. Raoul Island remained at Alert Level 2 (minor eruptive activity).

The eruption at Augustine may be approaching its end.
Activity at Augustine declined to low levels during 7-14 April, with seismicity decreasing to slightly above background levels, and rockfalls and avalanches decreasing in frequency in comparison to previous weeks. Low-level eruptive activity continued, consisting of slow effusion of lava at the summit accompanied by small rockfalls and avalanches on the volcano's flanks. Satellite imagery showed a decline in thermal output consistent with the decreased activity. Sulfur-dioxide gas measurements showed continued high levels of magmatic gas emissions that may have been associated with degassing of lava at the summit of the volcano. Augustine remained at Concern Color Code Orange.

Jorge Clavero Ribes from the Chilean Geological Survey (Sernageomin) and Juan Cayupi-Chilean Emergency Office (ONEMI) sent the following report about the recent eruptions at Lascar volcano:

Dome observations suggest continued lava extrusion throughout the reporting period. Growth has occurred over a sector extending from the east around to the north. The eastward-facing lobe has continued to grow on the northeast side of the dome and a whale-back feature was observed on 18 April. Numerous small rockfalls continued to fall from the active eastern flanks of the dome, adding to the talus in the upper reaches of the Tar River valley. Rockfall activity has been accompanied by minor ash venting. Due to the unusual wind conditions, the plume has predominantly been transported to the north and northwest shifting to east on 20 April. Due to this and frequent rockfall activity light ashfalls have occurred over much of the island.

Based on the latet monitoring reports, an eruption of Merapi seems imminent. Over the past three days (22-24 April), there have been 22 shallow volcanic tremors, 46 incandescent rockfall events, and 414 multiphase tremors. White steam and thick SO2 smoke of 200 m height is being emitted from the crater. The alert level of Mt. Merapi remains in level III (orange).

The activity at Ubinas volcano continues. Sixteen families from the southern Andean town of Querapi were evacuated to a village three hours away according to news reports. About 60 other residents had already been evacuated from the same village over the past three days. Between 40 to 60 livestock, including vicuna and llamas, died near the slopes of the crater, and many more were reported ill, probably from drinking acid-contaminated water or eating ash-coated grass.

Merapi volcano is still very restless. A evacuation plan is being prepared and the Indonesian Red Cross reported (21 Apr.) that 20,000 masks have been distributed to the communities near the volcano.

Lascar's eruption on 18 April 2006 (Photo REUTERS).

Lascar volcano IN TheCentral Andes (Northern Chile) started erupting on Tuesday morning (18 April, 2006). A column of steam and ash rose to about 3,000 m (1,864 miles) above the summit crater.

Tugurahua's strombolian acitivity has been increasing lately; in particular, the Institute of Geophysics and Volcanology in Quito reported an episode of lava fountaining from the crater last Sunday.

Ubinas volcano continues to be weakly active; an eruption on Monday 17 April sent a small ash plume to about 750 m above the crater. According to news reports, authorities asked a small 42 farming families comminity in Querapi, three miles from the volcano to leave as a precaution, without success.

Because of the recent interesting volcanic activity at Merapi and Semeru volcano on Java, we point to two tours with open spaces for last-minute individual bookings:

Merapi volcano is getting more and more restless, as authorities are trying to prepare for an evacuation of possibly several tens of thousands of people living in villages near the volcano. Merapi is currently at the highest alert level before an eruption (3 out of 4, with 4 meaning a significant eruption in progress, 3: imminent eruption likely).
Our correspondant in Yogya reports that spectacular, incandescent rockfalls from the lava dome have increased in frequency and size although there haven't yet been any explosions on the summit yet: The lava dome still seems quiet, and an increase in steam and gas emission has been noted.

Observations suggest continued lava extrusion throughout the past week. Growth has occurred over a sector extending from the east around to the north, and an eastward-facing lobe has developed on the north east side of the dome.

More detailed information about the recent activity at Lengai has emerged: there was probably no explosive eruption as reported earlier, but one or two very large effusive paroxysms: the first eruption occurred on 29 March, the second probably on 3 April. The eruptions produced large-volume natrocarbonatite lava flows that overflowed the crater to the West near the climbing route, travelled for more than 1 km length through a small canyon before stopping less than two km from a Maassai village at the base of the mountain.
Buring vegetation ignited by the lava might have produced smoke that had been mistaken for ash. No evacuations have taken place and no one has left the area, different from early news reports.

Growth of the new lava dome inside the crater of Mount St. Helens continued during 5-10 April, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash.

Seismicity continued to decline at Raoul Island through 7 April. In addition, Green Lake's water level began to recede, ending the water-level increase that had occurred in response to the 17 March eruption.

On 1 April, scientists visited Poás volcano and confirmed that Laguna Caliente at the volcano's summit had widened, and that sediments and blocks fromthe lake's bottom and surrounding walls were ejected during the explosions on 24-26 March 2006. The lava dome's (or pyroclastic cone's) N wall was greatly fractured and a 40 x 7 x8 m segment of the wall was gone. In addition, a 40 x 4 x 6 m chunk of the SE wall of the lake was missing and must have been destroyed during the explosions. They also found that the lake was light gray due to large quantities of suspended sediments, had a temperature of 54 degrees Celsius, had a pH of 0.63, and the lake level had decreased in comparison to the level before the explosions.

Merapi volcano might erupt in the near future, the Volcanological Survey of Indonesia believes. The number of earthquakes below the volcano and steam emission from the summit crater have drastically increased during the past days. VSI raised the alert level to 3 ("an eruption could occur any time") and villages around the volcano are advised to be ready for possible evacuation should the volcano erupt.

The activity at Lengai volcano, that started around 30 March is still enigmatic. According to information compiled by our colleague Fred Belton, a lava flow and lava fountains were emitted on the 30th, but there were no ash emissions. A steam plume was visible that may have been mistakenly described as ash in news reports. According to an observer in Tanzania, on 4 April a very large lava flow was visible on the volcano's W flank. The lava flow was over 1 km long and had traveled down the flank of the volcano and into a gorge. There were no signs that the flow was still hot. Photographs revealed that another lava flow may have traveled W of the volcano on 3 or 4 April. On 7or 8 April, active lava was contained within a new lava lake (?) at the summit. There are contradictory reports about evacuations evacuations from villages near the volcano.

Ubinas volcano continues to erupt ash, producing plumes of 6-7 km height above the volcano drifting SW.

Santa Maria volcano's Santiaguito crater remains at elevated level of activity. Frequent ash explosions produce plumes reaching up to 3 km above the crater, and sometimes small pyroclasitic flows, decending the NE and NW flanks. Ash fall is frequent over the localities El Faro, Patzulín,  La Florida and others.

Pacaya volcano's activity remains low, with a small active lava flow about 250 m long.

Weak activity continues at Fuego, with strong degassing from the lava dome and a small lava flow traveling towards the Taniluyá ravine. Forest fires at the flank of the volcano render visibility around the volcano poor.

A pilot reported a minor eruption at Veniaminof volcano producing an ash plume of about 10,000 ft on Thursday April 6, 2006.

The lava dome of Soufrière Hills volcano on Montserrat continues to grow, with focus to the east, where a lava lobe is growing in that direction and the majority of rockfall and pyroclastic flow activity occur. One moderate-size pyroclastic flow occurred at around 10:30 (local time) on Sunday 2 April, resulting in minor ash fall to the west of the island. -->More on La Soufrière Hills volcano

During 29 March to 2 April, small-to-moderate explosions at Tungurahua consisted of gas, steam, and small amounts of ash. During the report period, ash fell in the Bilbao, Choglontos, Puela, and Manzano sectors, and incandescent blocks rolled down the volcano's NW flank.

Seismicity decreased at Poás volcano by 27 March, 2006. Harmonic tremor that was recorded during the recent heightened activity ceased. As of the 27th, no significant deformation was recorded at the volcano and abundant evaporation continued at Caliente Lake.

Weak vulcanian activity continues at Langila volcano's Crater 2. Eruptive activity was characterized by emissions of diffuse pale gray ash between 30 January and 7 February. Activity changed to subcontinuous forceful emissions of dark gray ash on 1, 2, 6, 7, and 9 March. The resultant plumes did not rise higher than 2 km above the summit crater (or 10,900 ft a.s.l.) before drifting WSW of the volcano. Weak-to-bright glow and weak projections of incandescent lava fragments were visible on 22, 23, and 28 February, and on 1, 2, and 6 March. There was no activity at Crater 3.

Seismic and thermal activity at Galeras has decreased, but the volcano remains on elevated alert.

Colima continues to erupt ash from time to time. The highest ash plume during the past week reached ~7.9 km (26,000 ft) a.s.l. after an eruption on 2 April at 10h52 local time.

During the past weeks, Bagana volcano remained weakly active, with small strombolian activity and a lava flow traveling down on its SSW flank. On 27 March an ash cloud was emitted.

Barren Island remains active. Pilots frequently observe ash plumes at around flight level 100. The volcano continues to emit small to moderate amounts of ash forming plumes travelling beneath 10-15000 ft (ca. 3-4,5 km a.s.l.) and extending for about 20 nm (30-35 km). -->More on Barren Island

Low-level eruptive activity continues at Augustine volcano, with no significant changes. There are occasional hot block-and-ash flows, rock avalanches, rockfalls, and lava flows. Small and dilute ash clouds resulting from this activity is most likely confined to the immediate vicinity of the volcano. Satellite imagery continued to show a thermal anomaly related to the new lava dome and lava flow. Augustine remains at Concern Color Orange. -->More on Augustine volcano

OVSICORI reported that on 2 April around 10:00 local time a small pyroclastic flow traveled down Arenal's W flank.

Increased fumarolic activity occurred at Ubinas during the end of March. A Universidad de San Agustin scientist who visited the volcano on 31 March found strong steam-and-ash emissions occurring. Also, leaves of nearby crops were burned and a sound similar to a jet engine emanated from the vent area.

There has been a possibly major summit eruption at Lengai volcano on 31st of March 2006, involving significant ash fall and lava flows from the summit, according to the following news report, posted on IPPMedia: