Montserrat Volcano Observatory


Morning Report
Report for the period 16:00 20 March
to 07:00 21 March 1997
The current alert level is AMBER


Activity at the volcano overnight has been at a low level. Small to medium rockfall signals have been the predominant phenomena recorded on the seismic network, although there have also been a few hybrid signals. One large hybrid earthquake at 4.15 am was followed by a rockfall signal and it is likely that this indicates a small pyroclastic flow from the Galway's Wall although no ash cloud was observed.

The top of the volcano is currently clear of cloud and vigorous steaming can be seen from the north side of the pre-September dome. Further good views of the dome should be possible later in the day.

The scientific team at the Montserrat Volcano Observatory would like to re-iterate the following points. The volcano remains active and potentially dangerous. The lava dome is currently larger than ever before. There are several areas on the eastern and south-eastern face which appear very unstable and further pyroclastic flows are likely. It also seems likely that there will be further pyroclastic flows from the dome above Galway's Wall, especially if an earthquake swarm occurs. These will give light ashfall in areas to the west of the volcano. Explosive activity similar to the September 17 event and possibly larger is still a distinct possibility. People entering zone C must remain alert, listen to Radio Montserrat and be ready to leave at short notice. Only essential visits should be made. The night-time visits by scientific teams into zones B and C are part of the routine monitoring and should not be taken as an indication that it is safe to spend the night in such areas. The ash levels in Plymouth are hazardous, and it is extremely important to wear an ash mask when there is ash in the air.


Montserrat Volcano Observatory