Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 29 December
to 16:00 30 December 1996
The current alert level is ORANGE

Rockfalls and small pyroclastic flows continue to be generated from the new dome. Seismicity is still high and the regular banded tremor has returned. Progressively larger pyroclastic flows are anticipated in the Tar River Valley, and large collapses of the new dome and older dome material could occur without warning. Ash generated from pyroclastic flows will be blown by the wind, probably towards the west. The instability of the Galway's Wall remains a concern, and the possibility of rapid escalation to explosive activity still exists.

There is no access to zone A/B. Restricted access is allowed to zone C/D, but only for essential purposes and by people with a means of rapid exit. All other zones have normal occupation.

There were no observations of the dome today due to poor visibility. A number of small to moderate ash clouds were generated by rockfalls and small pyroclastic flows from the dome. One of these, at 12:20 pm, produced ashfall in Plymouth.

The bad weather meant that no fieldwork was carried out today.

Seismic activity changed again today. The regularly-spaced bands of continuous seismic tremor have returned, although the size of the signals is lower than before. The interval between episodes is about ten hours. Swarms of large hybrid events are also being recorded, but these do not appear to be associated with the tremor. Numerous rockfall signals are also being recorded by the network, indicating continued dome growth within English's Crater. The numbers of these events has reduced slightly since yesterday, with 74 hybrid events, 24 rockfalls and 8 VT earthquakes being recorded.

Montserrat Volcano Observatory