Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 on 29 March 1996
to 16:00 on 30 March 1996

The eastern part of the dome has been very active today. Several rockfalls have occurred and caused large ash plumes. There have been light and variable winds, which has lead to ash deposits in the Corkhill and the Old Towne areas. Visual observations of the crater area were made from the helicopter and Whites this morning, and from Chances Peak this afternoon. Several unstable parts of the eastern dome were seen, and some of these have subsequently collapsed. The remains of a new spine were observed in the western crater, beneath Chances Peak. This spine has grown and then collapsed during the last four days. The rest of the crater area was generally quiet, but continues to steam and degas vigorously. Measurements of the height of the dome from Whites show that the dome has grown up to 4 metres (12 feet) since yesterday.

The seismic activity continues to be of a variable nature, and the level of activity has increased since yesterday. The seismicity has been dominated by 32 rockfall signals. Fifteen hybrid and two long-period earthquakes were also recorded but could not be located. One volcano-tectonic earthquake was located at 3 km beneath the northern crater.

The eastern and southern EDM triangles were measured today. The results show only very small changes since these lines were measured yesterday, consistent with the recent trends of slow deformation of the volcano.

A reorganisation of the seismic network was started today. The three-component station at South Soufriere Hills was moved to Chances Peak to replace the one-component station there. This will hopefully give more information about the nature of the seismicity. Two more stations will be installed in the south of the island over the next few days.

Members of the public are still strongly advised to keep out of the Tar River Valley area.

Montserrat Volcano Observatory