Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 08 October
to 16:00 09 October 1996

Seismic activity of the Soufriere Hills Volcano has remained at a low level during the past 24 hours. There has been a slight decrease in the number of rockfalls compared to yesterday. Visibility was generally poor but some observations were possible from Whites during the day. The October 1 dome has grown further, and is quite steep on the eastern face.

Only 9 rockfall events were recorded by the seismic network, a decrease since yesterday. Two hybrid earthquakes were also recorded, but these were very small. One regional event was recorded by the seismograph network at 00:35 on 09 October. Broadband tremor on the Gages seismic station has been at a higher level than yesterday; this may be due to increased steam venting as a result of intermittent downpours of rainfall experienced during the night.

Visibility was very poor for most of the day and few clear views were obtained of the volcano. The cloud base lifted marginally during the afternoon and allowed observation of the October 1 dome. The dome appears to have grown marginally and have experienced some slumping of material from the eastern side. This minor slumping of material may be related to the excessive amounts of rainfall which was experienced overnight.

No EDM measurements were made today due to the very low cloud cover which persisted throughout the day.

Installation of the new broadband seismic stations continued today. A new station was installed at Long Ground and the link to the Observatory through Bethel was completed. Fine tuning of the entire installation would begin tomorrow.

The continued rapid growth of the October 1 dome means that rockfalls and possibly pyroclastic flows may occur during the next few days. All indications suggest that these would be mainly confined to the Tar River Valley but may produce ashfalls which would affect areas to the west of the volcano.

Individuals put themselves in extreme danger if they venture beyond the Long Ground area into the Tar River valley. Further pyroclastic flow activity could start at any time, and could kill anyone in the immediate area. Resident are reminded that there is a possibility of further explosive activity during this period of dome growth. Everyone who passes through the checkpoints are reminded that they are entering areas which may become unsafe very quickly, and that they should be on maximum alert at all times while in the danger zone.

Montserrat Volcano Observatory