Government Information Service

The Volcanic Explanation
For The 24 Hour Period Ending 7 AM On Tuesday April 29, 1997
A Presentation Of The Government Information Services
In Conjunction With The MVO.

The current alert level is AMBER

Once again the Soufriere Hills Volcano has been quiet over the reporting period. In the 24 hours ending at 7 am this morning there were in the region of 100 rockfall signals but very little in the way of earthquake activity. The few that did occur were long period events some of which caused rockfalls from the dome.

This style of activity has been with us for about two weeks and shows that there is moderate growth of the lava dome (estimated at about 2 cubic metres per second).

The visibility has been poor over the reporting period and very few views of the dome were possible. However a helicopter took scientists to Chances Peak where the cracks there were measured. The growth of these cracks has slowed down over the past few weeks with it widening by about 6 mm since the last measurements of about three weeks ago.

This makes scientists believe that there has been a reduction of the stress on Galways Wall and Chances Peak which have been under constant pressure from the dome growing in the crater.

A long occupation GPS survey was started yesterday (Monday) to measure the line length between Chances Peak and Harris' Lookout - the survey will finish today and results published later. The results will show if there are any movements in the Chances Peak area.

The alert level remains at AMBER. There should be no admittance to Zone A at all as this area is very dangerous. If entering ashy areas everyone should wear their ash masks.

Government Information Service