Montserrat Volcano Observatory

Daily Report
Report for the period 16.00 29 May
to 16:00 30 May 1997
The current alert level is ORANGE

The volcano has remained fairly quiet for the last 24 hours, with some small pyroclastic flows. The northern flank of the dome is still active, and small pyroclastic flows have travelled into the top of Tuitt's Ghaut.

The seismic activity has been similar to the last few days, with 73 rockfall signals, about the same as yesterday. There were 5 hybrid and one long-period earthquakes. Almost all of the recorded rockfall signals were caused by rockfalls on the eastern and northern face of the dome; the southern side remains inactive, with only small rockfalls that are not large enough to trigger the seismic network recording system.

The volcano has been cloudy again for most of the day. A helicopter inspection flight was made this morning, and fresh pyroclastic flow material was observed in the top of Tuitt's Ghaut. Some trees have been scorched, and pushed down the valley. The pyroclastic flow deposit stretches about 400 yards down the ghaut. Also, some fresh blocks of lava have bounced over the crater wall into the top of Mosquito Ghaut. The entire east face of the dome is active, with small pyroclastic flows in the last few days. These flows have not extended beyond the base of the dome.

Further COSPEC runs were made today, along the road to the south. The results from yesterday have been processed, and gave a value of about 750 tonnes per day of sulphur dioxide. This is about average for the last week, but significantly higher than the normal rate recorded at this volcano.

Observations today indicate that the dome is still growing, and threatening the northern ghauts. Further dome growth will continue to destabilise the existing structure producing more pyroclastic flows. Large pyroclastic flows could occur with no 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