Montserrat Volcano Observatory


Morning Update
Report for the period 16:00 04 August
to 07:00 05 August 1996


Activity at the Soufriere Hills volcano overnight was slightly lower than that seen during the preceding reporting period. However, the pattern of small- to moderate-sized rockfalls, and near-periodic, large-amplitude, low frequency, tremor, preceded by VTs and/or hybrid earthquakes and followed by hybrid earthquakes remained the same. Three periods of sustained tremor occurred during the reporting period. These episodes of VTs and/or repetitive hybrid earthquakes and near-harmonic tremor are probably associated with magma migration from shallow depths to the surface as the process of dome growth at the Soufriere Hills volcano continues.

Visibility was very poor during the early morning period because of low cloud cover and rain.

While the current phase of activity at the Soufriere Hills volcano continues, hazards in some areas of the evacuated zone have increased significantly. In particular, we expect significant-sized pyroclastic flows to occur more frequently in the Tar River Valley area. These will obviously be associated with ash clouds which will be blown on the wind, with areas affected by ashfall being determined by the wind direction and strength at that time. The Tar River Valley and surrounding areas are now extremely hazardous, and should not be entered under any circumstances. If activity continues, there is a risk that flows or ash surges may come over Farrells' Wall and the upper reaches of some of the ghauts closest to the Tar River Valley. People are, therefore, advised not to work these areas. We also urge individuals who continue to ignore this advice to think very seriously before making trips to these highly hazardous zones.


Montserrat Volcano Observatory