Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 26 April
to 16:00 27 April 1997
The current alert level is AMBER

The volcano has been quiet during the last 24 hours, with occasional small pyroclastic flows into the White River valley. Low cloud has restricted views of the dome, but the seismic pattern suggests that there is continued dome growth.

The broadband seismic network recorded a total of 59 rockfall signals during the past 24 hours, which is fewer than yesterday. There were 23 long-period earthquakes, with 20 of these triggering rockfalls from the dome. There were no volcano-tectonic earthquakes, and only 4 hybrid earthquakes were recorded today.

Visibility was poor today, but some views of the dome were possible from the helicopter this morning. Rockfalls and small pyroclastic flows have continued over the Galway's wall, particularly to the north side of the White River valley, with deposition of material as far as the road to the soufriere. The gully to the north of Galway's wall, that was scoured by the increased activity on 24 April, has now been largely filled in with debris.

Results from the GPS survey of a network of points across the north of Montserrat measured yesterday suggest that there has been no significant movement of these points.

Ash samples were collected from 12 locations to the west and north of the volcano today with a maximum thickness of 3 mm or one eighth of an inch of ash deposited in Plymouth since last weekend.

The volcano remains dangerous, and only essential visits should be made to the evacuated zone. There is still a lot of ash blowing around, especially in the very dry conditions at the moment, so people should wear masks when in the affected areas. The Tar River and White River valleys are extremely dangerous, and should not be entered under any circumstances.

Dr Sevkat Arafin from the Seismic Research Unit in Trinidad arrived today for a short tour of duty.

Montserrat Volcano Observatory