Montserrat Volcano Observatory

Morning Report
Report for the period 16:00 5 December
to 07:00 6 December 1996
The current alert level is ORANGE

The intense swarm of VT earthquakes has continued overnight, although at a slightly lower level than yesterday. Rock avalanches from the Galway's Wall continue and it is still very unstable. The revised risk map is in operation and there will continue to be no access into Zone A/B. Access to Zone C/D is restricted and all residents in Zone E are reminded to stay vigilant.

A total of 140 volcano-tectonic earthquakes have been recorded since 4 pm yesterday. This is a slight reduction from yesterday's overnight count. The largest earthquakes are still about the same size as yesterday, of up to magnitude about 3 on the Richter scale. A reduction in the number of VT counts may mean a reduction in the pressure underneath the dome and also a reduction in the shaking of the upper part of the mountain.

There were 6 rock avalanches from the Galway's Wall which were large enough to trigger the seismic networks, and there were also 5 rockfalls from the lava dome recorded overnight.

The GPS survey carried out yesterday has already been processed and the results show a continuation of the trend of no movement of the lower flanks of the volcano.

Visibility is poor this morning and no observations of the Galway's Wall or crater area have yet been made.

Montserrat Volcano Observatory