Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 27 June
to 16:00 28 June 1996

Activity at the Soufriere Hills Volcano has been at about the same level today as during the previous twenty-four hours. Small and moderate-sized rockfalls from the lava dome still dominate activity.

A total of 66 rockfall events were recorded during this period, slightly more than yesterday. The largest of these were at 20:02 and 21:58 on 27 June and at 11:46 and 15:31 on 28 June. The two rockfall events on 28 June generated small ash clouds which drifted over the Upper Gages Valley. The numbers of hybrid and long period events remained low; there were eleven hybrid events and fourteen long period earthquakes during this reporting period. There were also two volcano-tectonic events. There was some very low level broadband tremor recorded from 10:00 on 28 June onwards. There were two small near-regional earthquakes, at 20:02 and 20:12 on 27 June.

Visibility was very poor all day and no observations of the dome were possible

COSPEC measurements of the SO2 level in the volcanic plume were carried out today. The results show that the SO2 flux remains low, at about 160 tonnes per day.

No EDM measurements were made today due to the poor visibility. A recurring fault in MVO's GPS equipment meant that the GPS survey has had to be curtailed again. The University of Puerto Rico GPS survey continues, with measurements at stations in Tar River, Reid's Hill, St Georges Hill and Roaches Yard today. Initial processing of some of the data shows no significant changes since the last measurements in early May.

A series of gravity measurements were made today, mainly at stations in the GPS network. Gravity measurements will be made at regular intervals to monitor mass and density changes.

Richard Luckett and Jean-Pierre Viode left Montserrat today. Richard has been on the island for two months working on seismic data. Jean-Pierre has been here for two weeks, helping in many aspects of MVO's work.

The Soufriere Hills Volcano is still considered to be highly dangerous to people and property on it's eastern and upper western flanks. 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