Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 5 July
to 16:00, 6 July 1996

Compared to yesterday, there was a marked difference in the level of seismicity at the at the Soufriere Hills Volcano. Small rockfalls from the dome continue to provide the main evidence of activity but there were also some hybrid and long period earthquakes. Poor visibility prevented EDM deformation surveys but the MVO GPS programme was successfully resumed. Broadband tremor of vigorous intensity occurred at various times throughout the review period.

There was a notable reduction in the number of seismic events recorded today. A total of 11 rockfall events, 6 hybrid and 9 long period earthquakes were registered. The largest signals recorded were produced by two rockfalls occurring at 20:07 and 21:40 pm on July 5 and a hybrid event occurring at 12:26 today. These events were not big enough to produce large ash clouds. A near regional earthquake was also recorded by the network at 16:12 yesterday. Two periods of vigorous broadband tremor were observed from about 12:15 am to 03:30 am and from 06:10 to 07:00 am this morning. Tremor occurred variably thereafter.

Viewing conditions were extremely poor for the entire day. Views of the entire dome and EDM surveys were therefore not possible. The MVO GPS programme resumed today with a marathon campaign at the northern and eastern geodetic monuments. The results of the exercise were not ready for this report.

Mr. Mike James left the island today after nine week during which he worked on the estimation of the dome volume.

No COSPEC measurements were carried out today.

The Soufriere Hills Volcano is still 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 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