Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 23 November
to 16:00 24 November 1996
The current alert level is AMBER

Rockfall activity at the Soufriere Hills volcano reached its highest level yet from the October 1 dome this morning, indicating that dome growth continues apace. The volcano remains in a dangerous state, and the level of activity could escalate at any time. The number of rockfalls is likely to increase over the next few days to weeks, and there may be pyroclastic flows into the Tar River Valley. The Tar River and Long Ground areas remain especially dangerous and anyone entering these areas is risking death.

A total of 22 rockfall signals triggered the networks today. Some of these rockfalls were quite large and the period between 04:00 and 08:00 this morning was the most intense period of rockfall activity since 17 September, both in terms of number and size of events. In addition to rockfall signals, two long-period and a single volcano-tectonic earthquake were recorded; the VT was located at a depth of about 2.5 km (1.5 miles) beneath the crater.

The dome was very clear at first light this morning and a survey was possible from the helicopter. Once the results are processed, this survey and other information should provide an estimate of the volume of the dome, which in turn will provide scientists with information on the rate of dome growth over the past few weeks. Inspection of the dome revealed that the rockfalls early this morning have continued to fill the canyon at the eastern base of the dome, and rockfalls are travelling progressively further each time. These rockfalls are coming from the unstable northeastern flank of the dome. Reports of increased steaming from the Upper Gages soufriere were investigated this morning, but steaming appeared to be at its usual low level.

COSPEC measurements were attempted this morning but an equipment failure led to abandonment of the project. No EDM or GPS surveys were undertaken today.

Collection of rainwater and gas samples was made as usual today - these will be analysed over the next few days and the results will be made available to the relevant authorities.

Dr John Bennett of BGS left Montserrat today after a short visit.

Montserrat Volcano Observatory