Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 27 September
to 16:00 28 September 1996

The level of activity at the Soufriere Hills volcano has increased markedly over the last 24 hours. There have been many volcano-tectonic and hybrid earthquakes, which have been larger than any earthquakes recorded recently, although they are still too small to be felt. The volcano has been cloudy all day, so no visual observations of the crater area have been possible.

There have been 69 volcano-tectonic earthquakes during the day, and 17 smaller hybrid events. The VT and hybrid earthquakes have many similar characteristics, and are probably due to magma movement within the volcano. The number of rockfall signals continues to be low. Two small long period earthquakes were also recorded. The levels of broadband tremor were slightly lower than on previous days.

Visibility was poor all day. The scientists have spent time processing data collected recently. Further clasts from the 17 September explosion were collected today. Measurement and analysis of these clasts will help to better understand the eruption. No EDM measurements were taken. A visit was made to Chance Peak to repair the seismic station there. The scientists experienced a small ash fall while at the summit.

MVO scientists expect that rockfalls and possibly pyroclastic flows will occur during the next few days as the unstable sides of the new scar feature at English's Crater stabilise. All indications are that the rockfalls and pyroclastic flows will be confined to the Tar River valley area. Dust masks should be worn at all times in ashy environments, which may persist for some time as ash dries out and blows around. Drivers should exercise caution and consideration for other road users, especially when driving through areas still affected by ash or gravel.

Individuals put themselves in extreme danger if they venture beyond the Long Ground area into the Tar River valley. All individuals passing checkpoints in whatever part of the island are reminded that they are entering areas which may become unsafe very quickly, and everyone should be on maximum alert in all of these areas. All residents of southern Montserrat are asked to once again ensure that they are familiar with evacuation procedures.

Montserrat Volcano Observatory