Montserrat Volcano Observatory

Morning Report
Report for the period 16:00 21 April
to 07:00 22 April 1997
The current alert level is ORANGE

Volcanic activity was at a higher level overnight than over the past few days. There have been a number of moderate-sized rockfall signals. The largest event overnight was at 11:24 p.m. yesterday, when a pyroclastic flow signal was recorded for about 12 minutes. It is thought that this pyroclastic flow moved down the White River, although there have not yet been any reports of ash being seen during this event. There have also been a number of small long-period earthquakes as have been seen at levels somewhat above background over the past week or more.

Two regional earthquakes were recorded by the seismic networks overnight, one at 5:33 am and the second at 6:13 am. The locations of these earthquakes have not yet been determined. The first of these events triggered a rockfall from which a small ash plume was generated.

Currently there is low cloud clinging to the summit of the volcano, so no views have been obtained thus far today.

Despite the apparent low level of activity, the volcano remains in an unstable state, with dome growth in the southern region above the Galway's Wall continuing. Collapses from the dome could occur at any time. Residents of Montserrat should remain alert, and listen to Radio Montserrat for further updates. Ash masks should be worn in ashy environments; this is particularly important in the current dry conditions. Visits to zone C should be restricted to those that are essential. All of Zone A, which includes Long Ground and St Patrick's, is very dangerous and should not be entered under any circumstances.

Montserrat Volcano Observatory