Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 28 June
to 16:00 29 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 55 rockfall events were recorded during this period, slightly less than yesterday. The largest of these events occurred at 20:16 pm on June 28 and 01:39 am on June 29. Both events had durations in excess of one minute and saturated the records of the closest seismic stations. The number of long period and hybrid earthquakes remained low; there were four hybrid events and an equal amount of long period earthquakes during this reporting period. There was also one volcano-tectonic event which was located beneath the volcano at very shallow depth. Broadband tremor was consistently low throughout.

Visibility was slightly better than yesterday but no observations of the dome were possible.

No COSPEC measurements of the SO2 level in the volcanic plume were carried out today.

The Amersham - Dagenham - Chances Peak EDM triangle was measured today. The Amersham - Amersham line contracted by 2.2 centimeters in two weeks. There were no changes on the other lines. The Castle Peak target was restored this afternoon and the White's - Castle Peak line was subsequently measured. This linehas lengthened by 7millimeters since it was last measured 10 days ago. The University of Puerto Rico GPS survey continues, with measurements at chances Peak Tar River, Reid's Hill, St Georges Hill stations. The results of today's surveys are not yet available.

Neil Dyer left Montserrat today. Neil has been on the island for two months working on the GPS survey. Jane Toothill of Lancaster University arrived today and will be helping with the dome volume estimates

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