Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 05 June
to 16:00 06 June 1996

Volcanic activity at the Soufriere Hills Volcano has been at a moderate level today, dominated by small to moderate-sized rockfalls. Heavy rain induced a dilute mudflow in the upper parts of Fort Ghaut which was recorded by the Gages seismometer.

Seismicity at the volcano continues to be dominated by the occurrence of rock fall signals. There were 49 of these during this reporting period, a decrease compared to yesterday. The largest rockfalls were recorded at 02:21 and 06:34 on 6 June. No ashfall was reported from either of these events. There were 4 hybrid events today and 13 long period earthquakes. There have been brief periods of intermittent low-amplitude broadband tremor throughout the reporting period.

Sustained moderate amplitude broad-band tremor was recorded on the Gages seismic station from 11:14 to 11:40 this morning. It was not recorded on any other seismic station and, similar to yesterday morning's event, is thought to have been caused by heavy rain producing a sediment-laden flash flood or dilute mudflow. Fast-flowing, muddy water was seen and sampled in the middle reaches of Fort Ghaut soon after the seismic signal subsided.

Cloud cover prevented clear views of the summit of the volcano throughout the day although brief glimpses of the eastern flank of the dome showed abundant steam emissions and some small rock falls.

No EDM measurements were made due to the poor weather conditions.

COSPEC measurements of the SO2 gas concentration in the volcanic plume were not made today. The results from yesterday's 7 runs show an average SO2 flux of about 190 tonnes per day, a slight reduction from the previous day but consistent with most other recent results.

M. Christian Antenor-Habazac arrived on island today; he is a member of staff at the volcano observatory on Guadeloupe and will be assisting with technical work. M. Jean Battaglia departed today after a brief visit to assist with gas sampling at Galway's Soufriere. Mr Adam Maciejewski of the Open University also departed today after a month-long tour making FTIR and COSPEC measurements.

Scientists at the Montserrat Volcano Observatory continue to view the situation at the Soufriere Hills Volcano with grave concern. Visits to the evacuated zone should be kept to a minimum. The Tar River, Long Ground and Whites areas are extremely dangerous due to the frequent occurrence of pyroclastic flows in the Tar River valley. People should not enter these areas under any circumstances. If they do, they put themselves at direct risk of serious injury or death.

Montserrat Volcano Observatory