Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 on 16 October
to 16:00 on 17 October 1995

Twenty-two (22) earthquakes were located during the period under review. The events were mainly clustered in two areas, one directly beneath the Soufriere Hills volcano in the depth range 1-4km and the other just east of Windy Hill in the depth range 2-5km. The events were essentially all volcano-tectonic events.

Four steam and ash eruption signals were recorded by the seismograph network today, these occurred at 17:57, 22:45, 11:50 and 15:22. The 11:50 signal corresponds to the eruption which led to the mudflow down Hot River.

There were several episodes of broadband tremor and one period of low-frequency harmonic tremor of about thirty minutes duration, starting from 04:14.

Electronic Distance Meter measurements were made at the Tar River site. The measurements showed no significant changes from those made yesterday. The helicopter was used to help establish a reflector at the Roche's Yard DOS mark to act as a check on the measurements made at Tar River.

English's Crater was inspected from the air at 09:15am. At that time there were no significant changes to Castle Peak or the new dome, and steam venting was very low. During the second flight at 11:45, a large mudflow was observed to originate from within the crater moat just beyond the 28th July vent, running rapidly down the Hot River and reaching the sea. This mudflow is probably the largest (in terms of volume of material), to have occurred since the beginning of the current volcanic unrest at the Soufriere Hills volcano.

Montserrat Volcano Observatory