Montserrat Volcano Observatory

Daily Report
Report for the period 16.00 24 May
to 16:00 25 May 1997
The current alert level is ORANGE

The level of volcanic activity has remained high, with an increase in the number of rockfall signals suggesting an increase in dome growth rate.

There was one small hybrid earthquake swarm today, which occurred between 6:41 am and 11:36 am, about 18 hours after the last swarm. The swarm was of lower intensity than recent swarms, with only 47 hybrid earthquakes recorded in the period. There was however an increase in rockfall activity, with 154 recorded, which is the highest level of rockfall activity since the switch in dome growth to the northern side of the crater ten days ago. The increase in rockfall activity and decline in hybrid earthquakes suggests that the dome may be growing more freely. Data from the tiltmeter on Chances Peak suggests a decrease in the rate of deformation in the last 24 hours. The seismic network also recorded 16 long-period earthquakes, and increase in numbers compared with the last few days.

No visual observations were made today, because of persistent low cloud.

The volcano remains in an active and dangerous phase, with the dome threatening to over-spill the northern ghauts. This makes the Tar River valley, Long Ground, White's and Tuitt's areas very dangerous, and these areas should not be entered. Nobody should enter zones A and B, and only essential visits should be made to the evacuated zone. Ash masks should be worn when in the ashy areas.

Montserrat Volcano Observatory