Government Information Service

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

The current alert level is AMBER

There has been almost continuous rockfall signals from the Soufriere Hills Volcano over the last 24 hours. Prevailing winds have blown much of the ash produced into the safe zones and there have been ashfalls in Corkhill, Isles Bay, Old Towne, Olveston and Woodlands amongst others.

There have been in the region of 200 rockfall signals recorded on the seismic stations during the reporting period, this is one of the highest number for any 24 hour period this year. Some of these rockfalls produced pyroclastic flows into the White River Valley below the Galways Wall.

In addition there has been some earthquake activity with a number of long-period earthquakes being recorded.

The long GPS survey of Tuesday was completed yesterday and along with recent EDM measurements showed that there is a slow trend in that the distances from Farrells to Windy Hill and St Georges Hill are very slowly shortening. Line lengths of this nature are taken to show whether or not the mountain sides are bulging.

Ash levels in Plymouth, Corkhill, points south and in some areas of Old Towne and Olveston are at a high level. Everyone is urged to wear their dust masks as the ash can be hazardous to health.

The alert level is AMBER, but if current rockfall and pyroclastic flow activity continues at a high level it may become necessary to increase the alert level once again. The volcano is dynamic and changes must be expected at any time. Further ashfall is predicted for the safe zones because of the prevailing winds.

All residents are asked to keep clear of Zone A which is particularly dangerous, especially the Galways Soufriere and White River Valley area as well as the Tar River Valley and Long Ground area.

Government Information Service