Montserrat Volcano Observatory

Morning Report
Report for the period 16:00 16 January
to 07:00 17 January 1997
The current alert level is ORANGE

Activity at the volcano has been a low to moderate level overnight. A small sequence of earthquakes was recorded between 6:26 pm and midnight. This sequence consisted of mainly small volcano tectonic events but there were a few small long period events. Rockfall activity continued throughout the reporting period but at a lower level than it has been recently, and the events were relatively small. Last evening some small pyroclastic flow activity was observed in the vicinity of the Venus chute, south of Castle Peak. These traveled a few hundred meters from the base of Castle Peak. Ashfall was reported at St. Georges Hill.

Steam venting continues variably, but at a reduced level compared to recent days.

The summit of the volcano is partially cloudy this morning. Visual observations will be attempted from the helicopter.

The southeastern face of the dome remains unstable. Further collapses and associated pyroclastic flows into the Tar River Valley are expected during the next few days. If a major dome collapse happens, it would probably build up over a period of several hours, and would produce large pyroclastic flows in the Tar River valley and heavy ash fall downwind of the volcano. Should the collapse be very large, then an explosive eruption is possible, in the same way that it followed a major dome collapse on September 17/18. Zone E, which includes Corkhill and the airport, remains safe. The Tar River area is extremely dangerous, and should not be entered in any circumstances.

Montserrat Volcano Observatory