Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 25 March
to 16:00 26 March 1997
The current alert level is AMBER

The level of activity at the volcano has remained low over the last 24 hours. Rockfalls have continued to dominate the seismic records indicating that the dome complex continues to grow.

Visual observations were made today during a sequence of helicopter flights. Several areas of cracking and land-slips were noticed on the Gages Wall. This has not been seen on flights earlier this week and is thought to have occurred over the last few days. These will be carefully watched in the coming days for signs of further activity. This is further evidence that English's Crater is being stressed by the growing lava dome. A sharp spine on the western side of the dome which was first noticed a few days ago has continued to increase in height.

There have been only 4 hybrid and 9 long-period earthquakes during the 24 hour period. There were 21 rockfall signals, a slight decrease since yesterday. No volcano-tectonic earthquakes have been recorded by the seismic network today.

The long-occupation GPS between Harris Lookout and Hermitage was completed today. The results have yet to be processed. The results will be included in a future report.

The results from the EDM measurements on the northern triangle made yesterday indicate that there has been no change in the trend of the lines to the Farrell's target site. The slant distances continue to show minor fluctuations but are essentially stable.

Fresh growth at the summit of the dome has been observed in the last few days. The dome is now very big, and a dome collapse with large pyroclastic flows could happen with little warning. It is dangerous to spend the night in evacuated areas, because the situation could worsen rapidly over a period of a few hours. People entering Zone C are reminded to remain alert at all times, and spend the minimum possible time in the evacuated zone. The Tar River Valley and the upper Galway's area are very dangerous and should not be entered at any time.

Montserrat Volcano Observatory