Government Information Service

The Volcanic Explanation
For The 24 Hour Period Ending 7 AM On Wednesday May 21, 1997
A Presentation Of The Government Information Services
In Conjunction With The MVO.

The current alert level is ORANGE

The activity at the Soufriere Hills Volcano in Montserrat over the last 24 hours has been very similar to that of the previous reporting period. However, overnight and into this morning (Weds) the activity has somewhat reduced.

In the reporting period there were two major swarms of hybrid earthquakes with over 200 events and further pyroclastic flows from the north to northeast section of the dome. The northern side of the crater continues to fill up and material is threatening to spill over into Tuitts Ghaut and White's Ghaut.

Visibility at the dome has been poor over the last 24 hours, however the seismic records show that activity is in the area of recent dome growth and there have been numerous ash plumes from this area.

Some estimates of the dome size taken during the clear days of last weekend show that it now has a volume of 63 million cubic metres which makes it twice as large as it was last September. The dome is growing at a rate of 3.7 cubic metres per second which is higher than average.

The recent activity on the northeast face is causing debris to build up behind the Farrells crater rim and it is estimated that these material deposits are 20 to 40 metres thick. There is also some evidence from photographs that the northeast face of the dome is bulging from internal growth.

The alert level is ORANGE and as the dome continues to grow the danger increases and there could be a major collapse. As the dome outgrows the crater walls there will be more rockfalls and it is evident that there is increasing gas pressures within the dome. The Long Ground, Tar River Valley, Whites and Tuitts areas are extremely dangerous.

All residents are asked to remain vigilant and stay tuned to ZJB.

Government Information Service