Montserrat Volcano Observatory

Daily Report
Report for the period 5 p.m. 12 August
to 5 p.m. 13 August 1998

The level of activity at the volcano increased slightly today. There were 5 volcano-tectonic earthquakes and 45 rockfalls.

Two episodes of pyroclastic flow formation occurred. The first pyroclastic flow occurred at 05:19 and lasted about 10 minutes. The flow travelled about 1.8 km from the dome down the White River valley. The episode was followed by a period of small rock falls. A second pyroclastic flow occurred at 14:55, lasted 15 minutes and also travelled about 1.8 km. The flow was followed by about an hour of almost continuous small rockfalls. Both flows generated small ash clouds which drifted to the west over Plymouth.

The flows are mostly originating from an area of fumaroles at the boundary between the dome and Chances Peak in the Galways wall area. The fumaroles are no longer visible and appear to be buried by rockfall debris. Some flows and rockfalls are also originating from part of the dome about 150 m to the east, indicating that much of the dome above the Galways wall is becoming unstable. The cloud was too low to determine where these other rockfalls originate.

The EDM line from Windy Hill to the North crater rim was shot today and the results are being processed.

Dust levels were low at all stations.

Residents should continue listening to Radio Montserrat in case there are sudden developments in the state of the volcano.

Montserrat Volcano Observatory