Montserrat Volcano Observatory

Morning Update
Report for the period 19:00 15 August
to 07:00 16 August 1996

The level of activity during the night has remained about the same as that observed during the day time. Many small- to moderate-sized rockfalls were recorded and several of the largest ones were probably associated with small pyroclastic flows in the Tar River Valley. A sequence of small volcano-tectonic earthquakes occurred from 17:10 to 18:40 on 15 August. Preliminary calculation of locations for these events indicates that they occurred below English's Crater at depths less than 2 km. Two episodes of flash flooding in Fort Ghaut were detected by the Gages seismic station. Intermittent low-amplitude broadband tremor was recorded at the stations closest to the Crater throughout the update period.

Visibility during the early morning period was very poor, with the dome covered by low clouds.

Extreme care should be exercised when driving in areas affected by recent ashfalls.

Further rockfalls and pyroclastic flows will occur but all indications at the moment are that these will be confined to 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 extremely hazardous and should not be entered under any circumstances.

Montserrat Volcano Observatory