Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 22 April
to 16:00 23 April 1996

Seismic activity at the volcano has remained at the same level as of yesterday (22 April). The small, repetitive hybrid earthquakes are still being recorded at a rate of approximately 1 per minute. Rockfall and small explosion signals have been recorded throughout the day. An exception to the usual small size of these events was a series of rockfalls and explosions which started at 03:29 this morning and lasted for about 15 minutes. The seismicity returned to the background level after this sequence and has remained at that level throughout the day, punctuated occasionally by moderate rockfall/explosion signals. The series of events at 03:29 this morning was the only significant ash-producing event of the day.

EDM and GPS measurement have been made throughout the day. The eastern EDM triangle was reoccupied today. Comparison of these measurements with those obtained yesterday indicates that the slow shortening trend observed over the past few months is still continuing. At the time of writing, the GPS field team are making the most of the daylight and continuing measurements in the east of the island. These will be added to the growing data set which will form the basis of comparisons with future measurements.

Visual observations of the volcano have been hampered by the low cloud level which has persisted throughout most of the day. Rockfalls were heard by scientists working in the field. No significant ash clouds have been observed, again due to the poor visibility.

The scientists at MVO again wish to stress that the volcano is still at a level of increased activity. People should limit the time they spend in the evacuated zone to a minimum. The Tar River, Long Ground and Whites areas are extremely dangerous and should not be entered under any circumstances.

Montserrat Volcano Observatory