Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 07 October
to 16:00 08 October 1996

The 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. 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 11 rockfall events were recorded by the seismic network, a decrease since yesterday. Nine hybrid earthquakes were also recorded, but these were very small.

Visibility was poor during the day, but some views have been possible last night and during today. The eastern face of the October 1 dome is very steep, and there is vigorous steaming from the southwest of this dome and from the old dome complex. Several rockfalls were observed, and seemed to be originating from the base of the eastern face of the dome.

EDM measurements were attempted today on the eastern triangle to Castle Peak. The Whites to Castle Peak line was measured successfully, and showed a shortening of 8 mm since yesterday. This line, which was recently reestablished, has varied over the last few measurements, but the results are generally consistent with continued slow shortening of the line. The line has been shortening at a rate of 1 to 10 mm per day since it was first measured last December. Low cloud covered prevented measurement along the Long Ground to Castle Peak line.

Installation of the new broadband seismic stations continued today. A new station was installed at Bethel, and will be connected to the Observatory from tomorrow. A site was also prepared at Long Ground, and will be finished 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. There is still a lot of ash around, and dust masks should be worn if necessary.

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. 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