Montserrat Volcano Observatory

Daily Report
Report for the period 16.00 27 May
to 16:00 28 May 1997
The current alert level is ORANGE

The overall level of activity has been low for the last 24 hours, with a noticeable reduction in the number of recorded earthquakes.

There have been no volcano-tectonic or long period earthquakes and only 19 hybrid earthquakes during the reporting period. The hybrid earthquake swarm which dominated yesterday's seismic activity ended at about 8.40pm last night.

There have been regular rockfalls and small pyroclastic flows throughout the reporting period. Occasional incandescent blocks were observed falling into Tuitt's Ghaut last night and today several rockfalls occurred on the north eastern flanks of the dome above Tuitt's Ghaut. Small pyroclastic flows and rockfalls were also observed today on the southeastern flanks of the dome. The pyroclastic flows only reached the first break in slope in the Tar River Valley.

COSPEC measurements made this morning show a decrease in the sulphur dioxide emissions to 616 tonnes per day. This decrease reflects the reduction in volcanic activity over the last 24 hours.

The active area of dome growth appears to have increased to include southeastern, eastern and northern sectors of the dome. The northern flanks of the volcano are still active and the probability of pyroclastic flows entering Tuitt's, Mosquito or White's Ghauts remains high. Major pyroclastic flows may be occur with little warning in the Tar River and White River valleys. Nobody should enter zones A and B, and only essential visits should be made to the evacuated zone. Ash masks should be worn when in the ashy areas.

Montserrat Volcano Observatory