Activity at the Soufriere Hills Volcano during this period has continued at about the same relatively low level observed during the past several days. Seismicity continues to be dominated by small- to moderate-sized rockfalls. A few small long period events were also recorded. There was one episode of low amplitude broadband tremor recorded at the seismic stations closest to the volcano. This started at about 03:40 on 10 April and lasted for approximately one hour.
The Eastern EDM triangle was measured today and there have been no changes in the slant distances for the past six days. Measurements were also made on both the MVO and the University of Puerto Rico GPS networks.
Further COSPEC measurements were made today and the data is still being processed. Preliminary analysis of the data collected yesterday shows that the SO2 output remains low, at around 100 tonnes per day.
Visibility has again been very poor, with the volcano covered in cloud for most of the day. There have been a few brief partial glimpses of the dome. Rockfalls still seem to be concentrated on the northeastern flank of the dome.
Glen Matiolli of the University of Puerto Rico left Montserrat yesterday, having reestablished their GPS programme. Peter Francis and Adam Maciejewski from the Open University, U.K., arrived yesterday. They will be measuring gas concentrations using a technique called Fourier Transform Infra-Red Spectroscopy. Mike Dolan of Michigan Technological University, U.S.A., also arrived yesterday. Mike has been running the MVO world-wide web page on the Internet and is here on a fact-finding visit. Desmond Seupersad and Richard Robsertson of the Seismic Research Unit arrived yesterday and today respectively. Desmond will be helping with the seismic data processing and analysis while Richard will be focussing on deformation measurements in addition to his main duties as Chief Scientist and Head of the MVO when William Ambeh leaves on 15 May 1996.
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.