Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 12 August
to 7 am 13 August 1997

Activity at the volcano has remained at a high level with another hybrid earthquake swarm.

One hybrid swarm has occurred overnight. It started at 6:18 pm last night and is still continuing at the time of reporting. The number of earthquakes per minute has increased since about 5 am and is now at about the same maximum level as the swarms yesterday.

Last night some glowing was noticed in the area where the new dome growth is occurring behind Gages Mountain. Currently the summit is covered in low cloud.

Hybrid earthquake swarms are continuing which are thought to be associated with rapid extrusion of new dome material. The small explosions yesterday and on Monday demonstrate that further explosions may take place with little or no warning. Future explosions may be more intense and longer lasting than those already experienced. If explosions do occur, the central zone should be evacuated immediately and people in the northern zone should seek shelter under as strong a roof as possible. After an explosion small rocks and ash can be expected to fall everywhere on the island. Ash and falling rocks make driving hazardous. Ash is present in the atmosphere and masks should be worn outdoors.

Further pyroclastic flows are expected on all flanks of the volcano, and so at no time is it safe to enter the exclusion zone, including the Belham river valley. Access to the exclusion zone is completely restricted. The central zone is evacuated over night and people should not return to their homes until advised to do so. Everyone should remain vigilant and continue to listen to Radio Montserrat for any announcements.

Montserrat Volcano Observatory