Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 15 May
to 16:00 16 May 1996

Activity at the Soufriere Hills Volcano has not changed much since yesterday. Seismicity is still dominated by small- to moderate-sized rockfalls. The largest rockfall events were at 22:46 and 23:45 on 15 May and 05:04 and 11:29 on 16 May. Some light ashfall was associated with the 05:04 event. There were no other reports of ashfall. There were a few small long period events and small hybrid events but no VT events recorded during this period.

Visibility has been poor all day, with cloud obscuring the volcano.

EDM measurements were made on some of the lines of the western triangle; Amersham - Amersham, Dagenham - Amersham and Amersham - Chances Peak. These show no significant changes since they were last measured on 06 May. Measurements made on the University of Puerto Rico GPS network today were ruined because someone disturbed the equipment deployed at Harris's lookout, presumably accidentally. No GPS measurements were made on the MVO network.

The COSPEC equipment stopped working yesterday, probably due to the effects of ash. Repairs are being made locally with advice from the manufacturers in Canada. The FTIR programme has not yet started because of the poor visibility.

Mike Dolan left Montserrat early this morning, having completed his fact-finding visit.

Residents of areas affected by recent ashfalls are still advised to wear dust masks when working in these areas. More ashfalls from rockfalls and possible pyroclastic flows in the Tar River Valley area should be expected. The areas affected by ashfall depend mainly on the prevailing wind direction.

The present level of activity at the Soufriere Hills Volcano continues to cause concern to the scientists. The MVO urges that visits to the evacuated zone are kept to a minimum. The Tar River, Long Ground and Whites areas are extremely dangerous and should not be entered under any circumstances. We have noticed that people have approached the areas affected by Sunday's pyroclastic flows and that some people have even walked on parts of the flows. This is extremely dangerous. The flow is still very hot, with internal temperatures of several hundred degrees. There are also air and gas pockets inside the flow, which might collapse under a person's weight.

Montserrat Volcano Observatory