Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 06 September
to 16:00 07 September 1996

Activity at the Soufriere Hills volcano during this reporting period continued at about the same relatively low level as observed during the previous 24 hours. Volcano-tectonic earthquakes and small- to moderate-sized rockfalls still dominated the activity.

Forty nine (49) rockfalls, 25 hybrid and 46 volcano-tectonic earthquakes were recorded. The largest rockfall occurred at 10:39 today 07 September and led to the generation of a small pyroclastic flow whose associated ash cloud was blown westward over the Amersham and Kinsale areas. The volcano-tectonic earthquakes, which were generally located at depths less than 2km beneath English' Crater, occurred in two swarms: from 17:06 to 21:23 on 06 September and from 06:00 to 09:00 today. Intermittent low-amplitude broadband tremor was recorded at the stations closest to the Crater throughout the reporting period. Two moderate-amplitude broadband signals recorded by the Gages seismic station from 03:51 to 04:40 and from 13:27 to 13:48 today represent episodes of flash flooding in Fort Ghaut.

Although visibility during the day was generally very poor, there was a partial lifting of the low cloud cover during the later part of the day which made possible views of part of the dome from Bramble Airport. Vigorous steam emission from several parts of the dome was observed, with ashy steam being emitted from the uppermost part of the scar produced by recent collapses from the eastern flank. The gully excavated to the north of Castle Peak by recent rockfalls and pyroclastic flows is also rapidly filling up with debris. Ash generated during today's activity was blown westwards.

EDM measurements were not made today because of the low cloud cover and rain. The COSPEC is still out of commission.

Further rockfalls and pyroclastic flows will occur as the lava dome continues to grow within English's Crater, but indications at the moment are that the pyroclastic flows will be confined to the Tar River valley area. Areas affected by associated ashfalls will obviously depend on the direction and strength of the wind at the time. Dust masks should be worn at all times in ashy environments, and drivers should exercise caution and consideration for other road users.

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

Montserrat Volcano Observatory