Montserrat Volcano Observatory

Morning Update
Report for the period 16:00 16 August
to 07:00 17 August 1996

The activity level and its nature have remained about the same during the night as during the the day time. Activity continues to be dominated by small- to moderate-sized rockfalls from the flanks of the growing lava dome. A swarm of small volcano-tectonic events were recorded between 01:00 and 02:25 this morning, and preliminary locations for these again place them at shallow depths beneath the Crater. A few episodes of intermittent low-amplitude broadband tremor were recorded at the stations closest to the Crater throughout the update period.

Periodic glimpses of the dome were obtained during the early morning for Bramble Tower and from the Observatory. The eroded gully from the eastern part of the dome into the Upper Tar River area through which material was being channelled is almost full with debris. Occasional small rockfalls were also seen from the eastern flank of the dome. Steam emission was observed from several areas of the dome.

Extreme care should still 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