Montserrat Volcano Observatory


Morning Report
Report for the period 16:00 21 March
to 07:00 22 March 1997
The current alert level is AMBER


Activity at the volcano overnight continued at a similar level that observed yesterday. The dominant phenomena recorded on the seismic network have been rockfalls and small pyroclastic signals. These signals are generally larger both in maximum amplitude and duration than those recorded yesterday. Two VT earthquakes and one hybrid event have also been recorded by the seismograph network. Episodic low amplitude tremor on the Gages seismometer continued until about 10:00 pm last night.

Currently the crater area is partly obscured by cloud. Some steaming can be seen from the north side of the pre-September 17, 1996 dome. Further good views of the dome should be possible later in the day. Clear conditions last night meant that the incandescence was visible from many areas around the volcano. Activity was most pronounced from the upper most areas of the January 20 dome but evidence of activity was also present on the October dome.

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 and is continuing to grow. There are several areas on the eastern and south-eastern face which appear 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