Montserrat Volcano Observatory

Daily Report
Report for the period 4 pm 19 June
to 4 pm 20 June 1997
The current alert level is ORANGE

The level of volcanic activity has been low today but the level of activity began to increase again just before 4pm this afternoon.. There was a pulse of slightly higher activity last night between 8.30pm and 4.30am.

A GPS and laser binocular survey of the Mosquito Ghaut pyroclastic flow deposits was completed today. During the survey there was no activity in Mosquito Ghaut. Despite low cloud, observations made throughout the day suggest that rockfalls and small pyroclastic flows have been concentrated on the eastern flanks of the dome and have travelled into the Tar River valley. The dome cleared for a few minutes this morning and the MVO observer at the airport noted a steep and blocky summit with several rather stubby spines.

Rockfall signals dominated the seismic activity again today. There were 159 rockfall signals, a reduction from the 193 recorded yesterday. The number of earthquakes remained low, there were no volcano-tectonic earthquakes, only one hybrid earthquake and four long period earthquakes.

A second tiltmeter was installed on Chances Peak today which should enable more detailed interpretations of the tiltmeter data to be made.

A GPS station was installed on Perches Mountain yesterday and was collected again today. This is part of an ongoing experiment into long occupation GPS sites at the volcano by the University of Puerto Rico.

Further pyroclastic flows and surges could travel into Gages valley, Mosquito Ghaut, Tuitt's Ghaut or the Tar River valley at any time. The authorities and MVO advise that access to Plymouth is restricted for the time being. Zones A and B, which include Tuitt's, Bramble, Bethel, Spanish Point, Farms, Harris and Trants, are extremely dangerous and nobody should go into this area at all.

Bramble Airport remains operational, but the public are reminded that it is open only for essential travel purposes.

Montserrat Volcano Observatory