Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 on 22 Feb. 1996
to 16:00 on 23 Feb. 1996

The hybrid earthquakes, which were occurring at a rate of approximately one every 90 seconds, have decreased in both frequency and amplitude from about 20:00 last night (22 February). These hybrid earthquakes have decreased in amplitude to the point where they are now only appearing on the seismograph station at Chances Peak. The broadband tremor which died out during the last review period has reappeared. Intermittent episodes of this tremor were observed, at a low to moderate level, between 20:00 last night and 07:00 this morning. Seismic signals associated with rock fall events have been recorded on Gages and Chances Peak seismograph stations throughout the review period. The largest signals of this type occurred at 05:35 and 12:29 on 23 February; no ash falls were reported after these events.

EDM measurements were made on the eastern triangle today; movement of the Castle Peak reflector continues at a very slow rate of a few millimeters per day. Movements on the Farrell's reflector measured yesterday were again of the order of a few millimeters per day.

Visual observations were not made today due to the low cloud cover over the volcano throughout the day.

Mr Richard Robertson left Montserrat this morning at the end of his tour of duty.

Montserrat Volcano Observatory