Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 08 August
to 7 am 09 August 1997

Activity at the volcano overnight has remained at a very high level with continued explosive activity. An explosive eruption occurred at 09:11 pm. This was preceded by a swarm of hybrid earthquakes which started at 1600 and ended at the time of the explosion and consisted of 44 discrete events. A hybrid swarm started at approximately 04:00 this morning and was still continuing at 07:00 am.

The explosion occurred at 0911 pm. A loud rumble was heard at the MVO and an incandescent column of material observed rising from the dome, together with several intense bursts of glowing material. Heavy ash and fragmented pumice fall was experienced in Old Towne for about 40 minutes after the eruption. It is not yet known if there were associated pyroclastic flows.

The activity is still generally following a cyclical pattern with regular inflation and deflation of the volcano with explosive activity as the cycle reaches its peak. The periodicity of the events is approximately 11 hours +/1 hour. However, pyroclastic flows have also occurred outside the most probable time period, and so at no time is it safe to enter the exclusion zone, including the Belham river valley. The risk of further explosive eruptions remains high and the present pattern of activity is expected to continue.

There is ash in the air in the west of Montserrat and therefore dust masks should always be worn in these areas. Drivers should also be considerate whilst driving in ashy conditions. The Belham River valley is very dangerous and should not be entered. Access to the exclusion zone is completely restricted, and people should stay completely away from all the flanks of the volcano. Everyone should continue to stay alert, and listen to Radio Montserrat for any announcements.

Montserrat Volcano Observatory