Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 25 June
to 16:00 26 June 1996

Activity at the Soufriere Hills Volcano has been at a slightly higher level today than the preceding twenty-four hours. Small rockfalls from the lava dome continued to dominate the activity.

A total of 54 rockfall events were recorded during this period, compared to 37 yesterday. There were two moderate sized rockfall signals which generated small but visible ash clouds at 11:32 am and 12:48 pm today. Many of the rockfall signals have been larger than any of the past week. Hybrid and long period events remained at a low rate of occurrence. There were four hybrid events and six long period earthquakes. Tremor level was generally low throughout this period but there were a few times that it intensified.

Visibility improved only slightly today. Teams working in the Hermitage and Whites area reported small rockfalls. The dome was glimpsed for a short period from Whites at 10:00 am. It appeared wet and there was heavy steaming on the southwest flank. A small stubby spine was also seen on the northeast summit.

No COSPEC measurements were carried out today.

EDM measurements were made on the Windy Hill - St. Georges Hill - Farrell's triangle. The results of yesterdays measurements have shown an extension of between 2.5 and 2.8 centimetres on the lines to the Farrells target. This occurred over a six day period. Today's measurements however showed small contractions of 2 and 5 millimetres. The Reids Hill - St. Georges Hill - Radio Antilles GPS triangle showed no change since it was last measured 27 days ago. Site preparation of the first of two permanent GPS stations, at Hermitage Estate, continued today.

Despite the continued relatively low level of activity, the volcano remains highly dangerous to people and property on both it's eastern and upper western flanks. There have been similar quiet periods in the past and the activity could increase suddenly, with no warning. Visits to the evacuated zone must be kept to an absolute minimum. The Tar River, Long Ground and Whites areas to the east and upper Fort Ghaut, Gages Village and Upper Amersham areas to the west are all extremely dangerous. All access roads remain closed and people should not enter these areas under any circumstances. If they do, they put themselves and others at direct risk of serious injury or death.

Montserrat Volcano Observatory