Montserrat Volcano Observatory

Morning Report
Report for the period 16:00 03 April
to 07:00 04 April 1997
The current alert level is ORANGE

The activity at the volcano has changed overnight, with the occurrence of a swarm of shallow earthquakes. The number of rockfalls and pyroclastic flows has been low, although there was light ash fall in the Corkhill area last night.

The earthquake swarm started at 5 pm, and continued until about 4 am. The swarm consisted of both hybrid and volcano-tectonic earthquakes. The largest four earthquakes were recorded strongly across the network, and were of a similar size to the largest volcanic earthquakes recorded recently. These earthquakes would have been felt by people close to the volcano. A few of the earthquakes triggered small pyroclastic flows, probably over the Galway's Wall.

The visibility is quite good this morning, and there is not much ash production at this time.

The occurrence of an earthquake swarm suggests that dome growth may have slowed. Further changes in the nature of the volcanic activity could happen at any time, and further major pyroclastic flows could result. The alert level remains at orange, and so there should be no visits to zones A and B and only limited, short visits to zone C. Daytime occupation only is permitted in zone D. People should listen for further updates of the situation from the MVO. For the time being people are advised to remain vigilant and to always wear an ash mask in the dusty conditions. The Tar River and White River valleys are extremely dangerous, and should not be entered at any time.

Montserrat Volcano Observatory