Activity at the Soufrière Hills Volcano is low.

The seismic network recorded no seismic events related to the volcano this week.

Sulphur-dioxide measurements gave an average flux of 325 tonnes/day with a maximum of 585 and a minimum of 186 tonnes/day.

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 12 April 2013
MVO Weekly Report 5 - 12 April 2013
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Activity at the Soufrière Hills Volcano is low.

The seismic network recorded three rockfalls this week.

Sulphur-dioxide measurements gave an average flux of 372 tonnes/day with a maximum of 477 and a minimum of 255 tonnes/day.

Heavy rainfall early in the morning of 30 March generated lahars in several valleys and ghauts around the volcano, including in the Belham Valley. These started at about 2:30 am and lasted for more than an hour.

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 5 April 2013
MVO Weekly Report 29 March - 5 April 2013
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Activity at the Soufrière Hills Volcano is low.

The seismic network recorded five rockfalls, two volcano-tectonic earthquakes and one long-period event this week.

Sulphur-dioxide measurements were possible on only five days this week, giving an average flux of 529 tonnes/day with a maximum of 644 and a minimum of 348 tonnes/day.

There was a pyroclastic flow in the Tar River Valley at about 5 am (local time) on Thursday 28 March. The flow was not observed directly, but the deposits show that it travelled half-way down the valley, to between 1 and 1.5 km from the dome. There have been no reports of ash fall; any ash cloud was probably blown over Plymouth and out to sea. We have not been able to determine the source of the flow due to cloud cover, but it was probably the large slab recently observed to be peeling away from the dome above the Tar River Valley.

Heavy rainfall during the evening of 28 March generated large lahars in several valleys and ghauts around the volcano, including in the Belham Valley. These started at about 7pm and lasted for several hours.

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 29 March 2013
MVO Weekly Report 22 - 29 March 2013
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Activity at the Soufrière Hills Volcano is low.

The seismic network recorded one rockfall and three volcano-tectonic earthquakes this week.

Sulphur-dioxide measurements were possible on only three days this week, giving an average flux of 359 tonnes/day with a maximum of 540 and a minimum of 258 tonnes/day.

There appear to have been no changes in the large slab recently observed to be peeling away from the dome above the Tar River Valley. The slab is now estimated to have dimensions of 80 by 60 by 4-6 metres. If this slab falls as a single block it will produce a large pyroclastic flow in the Tar River Valley, safely away from populated areas

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 22 March 2013
MVO Weekly Report 22 March 2013
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Although there has been no extrusion of lava since 11 February 2010, scientists at the MVO keep a close eye on the state of dome, looking for changes such as increased rockfall activity, changes in the number and temperature of fumaroles or other general morphological changes caused by erosion. To do this, MVO conducts frequent observation flights, during which photographs and thermal images are acquired, and acquire satellite radar imagery.

Recent photographs and satellite radar images show changes on the dome that are the result of the activity on 4 and 5 February 2013. The activity included volcano-tectonic earthquakes, elevated gas flux and increases in activity at many of the fumaroles located inside the 11 February 2010 collapse scar on the north flank of the volcano. The increased fumarole activity resulted in the formation of a new crater around a prominent fumarole inside the collapse scar (see photo above), as well as the removal of material from around fumaroles near to the summit of the volcano. In the satellite radar image shown to the left, the cyan coloured area marked by arrows shows where the largest changes have occurred. This part of the dome is nearly always covered by cloud, so the radar images provide a very useful view of the dome, even when it can’t be seen from MVO.

In addition to the recent changes inside the 11 February 2010 collapse scar, degradation of the east side of the dome, at the head of the Tar River valley, has continued since extrusion stopped in 2010. On 8 March 2013, scientists observed a large fissure in the cliff in the east side of the dome, part of which has existed since 2007 (see photo to right). The presence of the fissure, parallel to the cliff face and estimated to be 2 m wide, suggests that a large slab is slowing peeling away from the dome. Should this slab fail as a single block, it will likely produce a large pyroclastic flow that would descend the Tar River valley, safely away from any populated areas. The formation of the fissure is a result of slow cooling and subsequent erosion of the dome, a process that will continue for many decades, even after the current eruption is over.

Activity at the Soufrière Hills Volcano is low.

The seismic network recorded one rockfall this week.

Sulphur dioxide measurements were possible on only three days this week, giving an average flux of 251 tonnes/day with a maximum of 264 and a minimum of 227 tonnes/day.

During a helicopter inspection on 8 March 2013, we observed a large fissure in the cliff on the eastern side of the dome, part of which has existed since 2007. This fissure is the result of slow cooling and erosion of the dome. It is parallel to the cliff face and is estimated to be two metres wide, suggesting that a large slab is slowing peeling away from the dome. If this slab falls as a single block it will probably produce a moderate-to-large pyroclastic flow in the Tar River Valley, safely away from populated areas

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 15 March 2013
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Activity at the Soufrière Hills Volcano is low.

The seismic network recorded one rockfall, two volcano-tectonic earthquakes and one hybrid event this week.

Sulphur dioxide measurements for the week gave an average flux of 368 tonnes/day with a maximum of 552 and a minimum of 213 tonnes/day.

Variable winds blew the volcanic plume over inhabited areas for much of the week, particularly the first half, and the smell of volcanic gases was very noticeable at times.

There has been no visible emission of ash from the volcano this week. MVO has received some reports of ash, but these could not be verified.

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 8 March 2013
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Activity at the Soufrière Hills Volcano is low.

The seismic network recorded one volcano-tectonic earthquake this week.

Sulphur dioxide measurements for the week gave an average flux of 503 tonnes/day with a maximum of 1078 and a minimum of 312 tonnes/day.

Variable winds blew the plume over inhabited areas on Thursday 28 February and the small of volcanic gases was noticeable at times.

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham valley are frequently destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 2. There is no access to Plymouth or Zone V. There is daytime access to Zone C: 8 am to 4 pm, Monday to Saturday. Maritime zone W remains daytime transit only (boats may sail through the zone but must not stop).

MVO Weekly Report 1 March 2013
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