Rockfall activity has continued on the dome during the last 24 hours, with small flows into the Tar River valley and the top of Tuitt's Ghaut. The upper parts of the volcano, including most of the dome, have been shrouded in cloud throughout the day.
The level of rockfall and pyroclastic flow activity was slightly lower than yesterday, with one peak in activity tailing off between 4 pm and 6 pm last night, and a further peak taking place between 3.30 am and 7.30 am this morning. During the peaks in the activity, rockfalls and small pyroclastic flows and rockfalls occurred on a wide sector of the dome, from the south-east round to the northern slopes. Most of the flows were into the Tar River valley, and a few ran down the upper reaches of Tuitt's Ghaut. Some of the pyroclastic flows were preceded by falling and bouncing boulders, which could be heard at a few kilometers distance.
Seismic activity at the volcano has diminished slightly over the last 24 hours: there were 12 small hybrid earthquakes and 19 long-period earthquakes, many of which triggered rockfalls from the dome. There were 124 rockfall signals in total, a small increase over yesterday but, in general the majority were very small events.
A survey of the pyroclastic flow deposits in Tuitt's Ghaut from the helicopter was completed this morning. These kinematic GPS measurements will give an indication of the volume of material which has been deposited there in the last few days.
COSPEC measurements were made late in the period under report, and results will become available tomorrow..
An extensive collection of rainwater and ash samples for the environmental monitoring programme was undertaken this afternoon.
Further rockfalls and pyroclastic flows are expected. The pyroclastic flows could easily extend down Tuitt's Ghaut beyond Bramble village. The revised zones A and B on the risk map should not be visited. These areas include Bramble, Bethel, Harris Paradise, Spanish Point, Farms, Trants, Riley's, Streatham, and Farrell's.. WH Bramble airport remains operational for the time being, although the public are reminded it is open for essential travel purposes only: people not travelling should not visit the airport.
Note: the place names used in these reports refer to locations identified on the Tourist Map of Montserrat as a reference, and may not correspond exactly to local variations or popular names.