Montserrat Volcano Observatory

Morning Update
Report for the period 16:00 14 September
to 07:00 15 September 1996

Volcanic activity overnight has been slightly higher than during the day yesterday. Several seismic signal which have in the past been correlated with pyroclastic flows were recorded during the period 16:00 to 19:36 on 14 September. One of these events, were observed to descend the upper Tar River-Hermitage area at 18:05 and generated ash clouds which drifted towards Plymouth. Small- to moderate-sized rockfalls continue to be the most common type of seismic signal recorded by instruments on the volcano. The larger of these events occurred during the 16:00 to 18:36 period on 14 September. There was one volcano-tectonic sequence during the night; this occurred between 23:39 on 14 September and about 01:30 on 15 September. Background tremor levels have been generally low throughout the night.

Visibility during the early morning was poor due to low cloud cover at the volcano. However partially clear conditions during the late evening yesterday allowed observation of several small rockfalls on the eastern side of the dome as well as the pyroclastic flow and associated ash cloud which occurred at 18:05.

Further rockfalls and pyroclastic flows will occur but all indications continue to be that the flows will be confined to the Tar River Valley area. However, areas affected by associated ashfalls will obviously depend on the direction and strength of the wind at the time. The rainfall during the late evening and overnight has made roads very slippery so extreme care should be taken when driving in affected areas. Dust masks should be worn at all times in ashy environments.

The Tar River Valley and surrounding areas are extremely hazardous and should not be entered under any circumstances.

Montserrat Volcano Observatory