Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 23 September
to 16:00 24 September 1996

Activity at the Soufriere Hills volcano during this reporting period has continued at a very low level. Visibility remains poor and no views were again obtained of the crater area.

There were about fifty-eight rockfalls recorded during the reporting period. These were very small events and may be related to continued stabilisation of the dome. Intermediate broadband tremor was recorded at a low amplitude on the Gages seismometer from the 16:00 on 23 September up until 24:00, thereafter decreasing throughout the remainder of the reporting period. One regional earthquake was recorded at 07:42 on 24 September by all seismic stations located on the volcano. The earthquake was 5.2 (Mt) on the Richter scale and was located at 152km depth, approximately 40km north of Martinique. The earthquake was felt in Martinique and St Lucia.

Visibility was very poor all day and no views of the dome or scar were obtained.

No EDM or GPS measurements were made by the MVO today. Reoccupation of GPS stations operated by the University of Puerto Rico continued today. Stations at Hermitage and Chances Peak were occupied during the reporting period.

MVO scientists are expecting more rockfalls and possibly pyroclastic flows to occur during the next few days as the unstable sides of the new scar feature at English's Crater stabilise. All indications are that the rockfalls and pyroclastic flows will be confined to the Tar River valley area. Dust masks should be worn at all times in ashy environments, which may persist for some time as ash dries out and blows around. Drivers should exercise caution and consideration for other road users, especially when driving through areas still affected by ash or gravel.

The extensive damage which occurred in the Long Ground area last week demonstrates the extreme danger which individuals subject themselves to if they venture into this area or beyond into the Tar River valley. The Tar River and Long Ground areas are now extremely hazardous and we urge individuals who persist in ignoring this advice to think very seriously before making trips to these potentially deadly zones.

Mr LeVar Cabey left the island late this afternoon to begin a 3-year Geophysics Degree program at the University of Lancaster. LeVar has been with the MVO since the beginning of the crisis in July 1995 and has assisted mainly in the processing of seismic events. The MVO wishes LeVar the very best in his studies and look forward to the summer vacation when he would again become involved in the monitoring effort. Dr Alan Smith of the University of Puerto Rico also left the island today after a brief visit. While here he assisted with the reoccupation of the University of Puerto Rico's GPS network and with the investigation of fresh pyroclastic deposits from last Tuesday's activity.

Montserrat Volcano Observatory