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 overall level of volcanic activity has been lower over the past 24 hours, with a hybrid earthquake swarm being the most significant event. There were no further pyroclastic flows during the same period.

The feature which dominated the activity today was a hybrid earthquake swarm, which lasted from around 4:00 am to 1:00 pm this afternoon. The swarm lasted longer than most other recent swarms but was of a lower intensity, with 86 hybrid earthquakes recorded in the period. At the end there was an increase in rockfall activity from around 1:20 pm through to the end of the reporting period. A total of 48 rockfall signals were recorded. There were also one volcano tectonic, 2 long period and one regional earthquakes.

A field team visited Chances Peak today to download data from the strong motion earthquake recorders deployed on the crater rim. The instruments were triggered by two relatively intense earthquakes. Data from the Chances Peak tiltmeters suggests a probable decrease in the rate of deformation in the last 48 hours. Low clouds shrouded the flanks of the volcano for most of the day but limited views were possible from Chances Peak because the winds predominantly came from the south and south-east. No marked changes were observed on the Galways and Chances Peak sides of the dome. A few small rock avalanches were witnessed down the Galways slope and also along the area midway between Chances Peak and Gages. Several rockfalls and rock fracturing could however be heard in the distance coming from the Farrells side of the dome. Some small ash clouds were produced but they didn't travel far from the summit.

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