Montserrat Volcano Observatory


Morning Report
Report for the period 4 pm 19 August
to 7 am 20 August 1997


Activity at the volcano remains at a high level with hybrid swarms and occasional small pyroclastic flows. A hybrid swarm occurred between 7.10 pm and 11.20 pm yesterday evening. This swarm did not build up into tremor, as has often happened recently, but towards the end of the swarm a small pyroclastic flow signal was recorded. Since then seismicity remained at a low level, with occasional rockfall signals, until 6:28 this morning when a small pyroclastic flow went into Gages valley. There was no change in seismicity before this flow.

Further explosions may take place with little or no warning. These may be more intense and longer lasting than those already experienced. If explosions do occur, people should seek shelter under as strong a roof as possible and have a helmet or head protection available. 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.

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 areas south of the Nantes River have been evacuated over night. Everyone should remain vigilant and continue to listen to Radio Montserrat for any announcements.


Montserrat Volcano Observatory