Activity at the Soufriere Hills Volcano has been very high for the past 7 hours with semi-continuous pyroclastic flows, mudflows and at least one magmatic explosion.

At about 3:50 pm, a period of pyroclastic flow activity commenced. This was correlated with heavy rainfall on the volcano and also included some mudflow activity. The amplitude of the pyroclastic flow signals increased gradually with several pulses of higher level activity. Pyroclastic flows could be seen travelling down the Tar River valley to the sea, and ash from these events appeared to be drifting westwards although visibility was very poor due to low cloud

A marked increase in the size of the seismic signals occurred after 7 pm with saturation on all seismometers in the short period network. At about 7.15 pm, glowing rock falls could be seen to the north-east of the volcano and these were followed by a sudden vertical explosion with red ballistics being shot to a few hundred metres above the summit of the volcano. Loud roaring and thunder could be heard and lightning was also observed in the ash clouds from this explosion.

About 30 minutes later the signals had largely subsided to background levels with a few low amplitude rockfalls continuing. Light ash fall occurred across the island, and satellite information from NOAA suggests that the ash cloud from the main event reached at least 30,000 feet and travelled to the south-east.

Observations in the Belham valley showed that significant mudflows had occurred down the valley with large boulders being transported across the Belham Bridge.

It is thought that the heavy rain triggered a continous collapse of the new lava dome for about three hours, which in turn led to the magmatic explosion from the volcano.

Although levels are much lower, the MVO will continue to monitor the activity throughout the night and give updates on ZJB if activity increases. Observations will be made as early as possible in the morning, and assessments of the activity reported during the day.

It is possible that further dome collapses and explosions may occur, and residents of and visitors to Montserrat are advised to tune in to ZJB Radio for up-to-date information on the status of the volcano.

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