Montserrat Volcano Observatory


Morning Report
Report for the period 16:00 19 March
to 07:00 20 March 1997
The current alert level is AMBER


The earthquake swarm which began yesterday died out around midnight, with only a few small hybrid earthquakes being recorded after this time. From around 2:00 am onward the dominant form of seismicity is in the form of small and moderate-sized rockfall signals. Low amplitude tremor on the Gages seismic station began at about 10 pm last night and is continuing at the time of writing. The seismicity indicates that the dome continues to grow.

Low cloud on the top of the volcano is currently hampering views of the dome and crater, although the cloud is clearing and good views may be possible later in the day. Views of the dome obtained last night indicate that current growth is concentrated in the summit region of the January 20 dome. There is still activity on the October dome as indicated by areas of incandescence. These observations reinforce the idea that the dome is still growing.

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. 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