Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 02 September
to 16:00 03 September 1996

Activity at the Soufriere Hills volcano during this reporting period was at about the same level as that observed during the previous 24 hours. Episodes of small- to moderate-sized rockfalls and pyroclastic flows and a swarm of small volcano-tectonic and hybrid earthquakes were recorded.

Fifty two (52) rockfalls, 25 hybrid, 1 long period and 110 volcano-tectonic earthquakes were recorded during this period. A period of small- to moderate-sized rockfalls and a few small pyroclastic flows from 16:00 on 02 September was followed at around 22:00 by an increase in the number of moderate-sized rockfalls and pyroclastic flows. This increase continued until about midnight when there was a near-continuous occurrence of pulses of pyroclastic flows till 03:00 this morning. Another less vigorous episode of pyroclastic flow activity occurred during the period 13:08 to 16:00 today. The rockfalls and pyroclastic flows were confined to the Tar River Valley area. Areas affected by ashfalls from the events of early this morning probably included most of the central corridor and the northwest (Dyers, Streathams, Lees, Gages, St. George's Hill, Weekes, Foxes Bay, Delvins, Garibaldi Hill, Isle Bay, Old Towne, Olveston, Salem, etc) while this afternoon's events resulted only in very light ashfalls in the St. George's Hill, Weekes and Garibaldi Hill areas. Some of the flows during the night may have reached the sea but the furthest flow front today afternoon ended just beyond the Tar River Estate House. Maximum estimated ash cloud height today was 7,000 ft above sea level for pyroclastic flows at 06:55 and 13:08. The swarm of volcano-tectonic and hybrid earthquakes occurred from 09:27 to 12:30 and the VTs were located at depths less than 2 km beneath English's Crater.

Visibility today was not very good but observations from the ground in the east confirm that the rockfalls and pyroclastic flows are occurring from the eastern flank of the dome and are generally being channelled towards the southern part of the Tar River Valley within a deep gully excavated just north of Castle Peak by the recent pyroclastic and rockfall activity. Vigorous steaming was also observed in the area just behind Castle Peak

COSPEC and EDM measurements were not made today because of instrumental problems and the low cloud cover respectively.

Further rockfalls and pyroclastic flows will occur but all indications at the moment are that the pyroclastic 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. Intermittent rainfall has made roads very slippery so extreme care should be taken when driving in ash affected areas. Dust masks should be worn at all times in ashy environments.

The Tar River Valley and surrounding areas are now extremely hazardous, and should not be entered under any circumstances. We urge individuals who continue to ignore this advice to think very seriously before making trips to these highly hazardous zones.

There will be a meeting at Cork Hill Methodist Church tomorrow Wednesday 04 September at 19:30, the purpose of which is to discuss with the residents of Cork Hill, Delvins, Weekes and St. George's Hill the impact of the volcano on their community. Everyone is invited.

Montserrat Volcano Observatory