Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 9 July
to 16:00 10 July 1996

There has been a notable increase in activity at the Soufriere Hills Volcano over the past day. Small to moderate sized rockfalls from the lava dome were the dominant events of the day. Visual inspection of the lava dome revealed that the system may be undergoing another change in the focus of growth but it is too soon to tell.

Rockfalls were at the highest level since the passage of hurricane Bertha on Sunday. Twenty-two rockfalls and two hybrid earthquakes were recorded by the seismic network. Compared to the signals recorded during the last week or so, most of the events during the reporting period were generally longer in duration. The largest rockfalls occurred at 23:06 on 9 July and on 14:44 and 15:20 on July 10. The latter two events generated light ash clouds that were driven westwards over Gages. Long period earthquakes remained low, with only four recorded over the reporting period. One locatable volcano-tectonic earthquake was also recorded. Low-amplitude broadband tremor was recorded has been consistently low throughout.

A short period of good visibility was available this morning. The dome was viewed both from the ground in the east and from the air. From Whites and other areas in the east several rockfalls were seen coming down the east to south-east sector of the dome. From the air it appeared that rockfall activity was again spreading to other areas within the vicinity of recently active south-eastern section. More fresh material had accumulated down the southern side of Castle Peak, indicating that this area was still actively growing. The area behind castle Peak was steaming vigorously and lots of fumarolic activity was coming from the summit of the south-eastern peak and the saddle area between the two peaks now resident inside English's Crater.

EDM measurements were taken today but the results are not yet available. 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 88 tonnes per day. The GPS campaigns were resumed today. The results from yesterdays processing were still not ready.

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 a minimum. The Tar River and Long Ground areas to the east and upper Fort Ghaut, Gages Village and Upper Amersham areas to the west are all extremely dangerous. All access roads to these areas 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