Montserrat Volcano Observatory

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

Volcanic activity has continued at a relatively low level overnight. The dominant form of activity has been rockfalls and small pyroclastic flows. A period of enhanced rockfall and pyroclastic flow generation occurred between 6 pm and 10 pm last night although there was no distinct peak in the activity. Following this the activity diminished to isolated rockfalls. A further reduction in activity was observed between 4 am and 6 am this morning. Following this there have been a number of small volcano-tectonic earthquakes and small rockfalls.

Recent activity has been focused on the dome above Tuitt's Ghaut. However, there are still large unstable areas of dome above Gage's Wall and Galway's Wall. The area of activity could change very rapidly making all sectors of the volcano very dangerous.

Although levels of activity have been lower in the last 48 hours, the pr obability of larger collapses remains high. The timing and size of these collapses is impossible to predict, but large pyroclatic flows could travel far down the Belham Valley as far as the sea. Residents of the exclusion zone south of Nantes River are thus urged to move north, as pyroclastic flows in the Belham Valley could produce surges threatening the Friths, Old Towne, Olveston and Salem areas.

Large collapse espisodes have in the past lead to explosive activity at the volcano, and residents are reminded that ash and rocks could fall anywhere on the island during such activity. If an explosion occurs, seek shelter indoors under a strong roof. All Montserratians are advised to keep listening to Radio Montserrat for updates on the situation.

Montserrat Volcano Observatory