Montserrat Volcano Observatory

Morning Report
Report for the period 16:00 16 March
to 07:00 17 March 1997
The current alert level is AMBER

Seismic activity at the volcano overnight has been quiet for most of the reporting period. Rockfall signals are currently the dominant form of seismicity. These are generally only small but a few larger ones have occurred through the night. A series of three large rockfall signals shortly after 1.00 am this morning probably represent small pyroclastic flows, and it is most likely that these originated from the active eastern and south-eastern areas of the dome. Two small and one large hybrid earthquakes have been recorded by the network. Two of these earthquakes have occurred between 6.45 am and 7.00 am and could represent the start of another earthquake swarm. There has also been low amplitude tremor on the Gages seismic station for most of reporting period.

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. Last night occasional views of the dome were obtained from Whites. Observations were consistent with the seismic activity in that some glowing blocks could be seen falling from the south-eastern, eastern and north-eastern faces of the 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. 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 ash levels in Plymouth are hazardous, and it is extremely important to wear an ash mask when there is ash in the air.

All at MVO would like to wish everybody a very happy St. Patrick's Day.

Montserrat Volcano Observatory