Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 04 May
to 16:00 05 May 1997
The current alert level is AMBER

Rockfalls and small pyroclastic flows have dominated activity over the reporting period. Moderate visibility enabled some views of the dome to be obtained this morning, and dome growth was confirmed to be continuing in the southern part of the crater.

The broadband seismic network recorded a total of 88 rockfall signals during the past 24 hours, almost exactly the same number as yesterday. Most of these rockfalls are quite small and they are again occurring both on the White River and Tar River side of the dome. There were 22 long-period earthquakes, of which 17 triggered rockfalls. One volcano-tectonic earthquake was also recorded today but it was too small to locate.

Observations of the dome were made by helicopter late this morning. The area of active growth is still in the southern part of the dome, with material shedding down both the southwestern and southeastern flanks into the White River and Tar River valleys respectively. The high-point on the dome is at the same height as when last observed, but the area around it has grown substantially in volume. With near-continuous rockfall activity, it is difficult to assess the current rate of growth of the dome, but it is certainly slower than during the time prior to large collapses earlier in the year.

An EDM survey is currently under way on the northern triangle - the results will not be available until tomorrow. The results from the GPS survey to Perche's Mountain show that there has been no movement in that area since the last occupation in early April.

The volcano remains dangerous, and only essential visits should be made to the evacuated zone. People should wear masks when in the ashy areas. The Tar River and White River valleys are extremely dangerous, and should not be entered under any circumstances.

Montserrat Volcano Observatory