Montserrat Volcano Observatory

Daily Report
Report for the period 4 pm 2 October
to 4 pm 3 October 1997

Activity over the last 24 hours has been at an overall lower level than has been experienced since September 21. There has only been one explosion during this reporting period.

The explosion occurred at 10:50 pm last night. Pumice flows from this event entered Gage's Valley and flooded across the northern flanks of the volcano into Tuitt's Ghaut. A roaring sound lasted for 5 minutes after the initial explosive start to the event. Ash was deposited on much of western Montserrat and is known to have reached as far north as the Observatory at Mongo Hill. There have been no further explosions following this event up to the end of the reporting period.

Apart from the one explosion, the last 24 hours have again been relatively quiet seismically. 3 hybrids, 6 volcano-tectonic earthquakes and 2 rockfall signals triggered the seismic network. Post-explosion tremor lasted for just over 1 hour after the explosion at 10:50 pm. This tremor was associated as usual with vigorous ash and steam venting and roaring noises from the volcano. There were no seismic precursors to this explosion.

Visual observations confirmed relatively small pyroclastic flows generated by last night's explosion. The crater and scar on the dome appeared relatively stable, although the crater does appear to be enlarging somewhat. Low level venting of gas and ash has been occurring throughout the day and some small rockfalls both within the scar and crater and from the outside face of the dome in the Galway's area have been noted.

The chance of more explosions cannot be discounted and these could be larger than anything seen so far. The resulting pyroclastic flows could very easily reach the Belham valley and surges could travel up the valley sides for a considerable distance. All those remaining in the exclusion zone are urged to leave. If the sirens sound in this area at any time, people should move north immediately.

After an explosion fallout can occur anywhere on the island. People should shelter in a strong building and wait for the fallout to end. If you do have to move about then head protection should be worn. Falling ash and pumice reduces visibility and makes driving conditions extremely hazardous. Roads remain difficult and plenty of time should be allowed for any journey. Drivers should be very careful. The wearing of ash masks is recommended at all times. Everyone is advised to keep listening to Radio Montserrat for information on the activity.

Montserrat Volcano Observatory