Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 24 June
to 16:00 25 June 1996

Activity at the Soufriere Hills Volcano has been at a relatively low level. The activity was dominated by small rockfalls from the lava dome.

A total of 37 rockfall events were recorded during this period, compared to 62 yesterday. All of these had signals which were small in amplitude and short in duration. There were two hybrid events and seven small long period earthquakes. Tremor was at a low level throughout this period.

Visibility was fairly poor for most of the day. There were two short periods when the entire dome was visible. It was clear from the ground that there are no spines on the top of the dome but it was not possible to determine where the active areas are. Unfortunately, it was only possible to see the lower flanks of the dome during helicopter flights. There has been very little change, with no new material that has come over Gages Wall and very little new material against Farrell's Wall.

No COSPEC measurements were carried out today.

EDM measurements were made on the Windy Hill - St. Georges Hill - Farrell's triangle. The results of these are not yet available. There was an 8-hour occupation of two of the GPS sites, Upper Amersham and Galways Estate, to help resolve the cause of some fluctuations seen in the data from Upper Amersham. Installation of the first of two permanent GPS stations, at Hermitage Estate, was started today with the help of volunteers from Her Majesty's Prison.

Three familiar faces returned on Saturday. Joe Devine of Brown University is back to help out with ground deformation studies. Alan Smith and Glenn Mattioli from the University of Puerto Rico are here to install permanent GPS receivers.

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