Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 21 November
to 6 pm 22 November 1997

Activity at the volcano has been elevated today with a large number of volcanic earthquakes and rockfalls.

Between 16:00 yesterday and 16:00 today there were 19 long-period earthquakes six of which were followed by rockfall signals, 59 hybrid earthquakes, two of which were followed by rockfalls and a total of 118 rockfall signals. Some of the hybrids were high amplitude, although most of them were relatively small. Rockfalls continued throughout the day. Visual observations of the volcano indicated that steam and ash venting occurred for most of the afternoon with the plume extending over Chances Peak towards Plymouth and the Gages area. This venting did not appear to be as vigorous as what was seen yesterday.

The level of ash in the atmosphere in St Peter's and in St John's, as averaged over the last 24 hours, remained low.

The dome is still growing and the growth area may switch rapidly at any time. The increase in hybrid earthquakes today suggest that the activity is changing and large pyroclastic flows or explosions may occur in the near future. Although the main activity is currently in the south-west sector of the volcano, further pyroclastic flows are likely in any of the ghauts around the volcano.

Montserrat Volcano Observatory