Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 1 November
to 6 pm 2 November 1997

Activity at the volcano has been at a relatively high level today with semi-continuous ash venting, pyroclastic flows and hybrid earthquake swarms.

Vigorous ash venting has been taking place for most of the day. The ash venting was first observed at 07:15 am this morning, between hybrid swarms, and produced ash clouds to around 10,000 ft. Strong easterly winds have produced extensive ashfall over Plymouth and environs. The venting was seen to occur in pulses coincident with the hybrid earthquakes. Some rockfalls have occurred from the October 22 dome down Tuitts Ghaut. In addition a number of small pyroclastic flows occurred down the Galways side of the dome and are probably due to continued degradation of the of the pre-explosion dome complex apparently triggered by hybrid earthquakes shaking the dome.

Brief glimpses of the dome indicate that the October 22 dome has two summits oriented in a NNE - SSW direction. Measurements indicate that the more northerly of the two of these summits has not increased in height since yesterday. The ash venting is considered to be coming from the south summit region.

There have been two hybrid swarms during the reporting period the first started at 5:00 pm on the 1 November and ended at around 5:30 am this morning. The second swarm began at 10:30 am this morning and is still continuing at time of writing. There have been a total of 532 hybrid earthquakes during the reporting period. Scattered throughout the day - both during and outside of the hybrid swarms - there were 38 rockfall signals and 20 long period earthquakes.

The level of activity on the volcano has been steadily increasing over the past few days. The MVO considers that the volcano is currently in an extremely dangerous state and more explosions or pyroclastic flows could occur at any time. Areas such as the Belham valley, around Trants and the airport are under a very real threat of being impacted by large pyroclastic flows. Under no circumstances, even for brief periods, should anyone be visiting these areas. Friths, Old Towne and Salem are also not safe. Anyone remaining in these areas is strongly urged to move out of the exclusion zone. Indeed any ghaut leading away from the volcano is especially dangerous because of the possibility of hot mudflows travelling down the valleys after heavy rainfall in higher regions. Stay tuned to Radio Montserrat for further information.

Montserrat Volcano Observatory