Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 25 April
to 16:00 26 April 1996

Seismic activity at the volcano continued at the same low level observed during the previous 24 hours until about 10:00 this morning when it increased slightly. The seismicity is still dominated by the occurrence of small, repetitive, hybrid earthquakes at a current rate of one per minute compared to one every two to three minutes before 10:00 this morning. The number of small to moderate sized seismic signals interpreted as rockfalls also increased. The most significant event during the period was a moderate-sized rockfall/explosion at 12:01. This resulted in an ash column which rose to about 4,500 ft above sea level and drifted to the northwest, depositing small amounts of ash in Plymouth and environs. This event also generated a small pyroclastic flow down the Tar River valley area.

No EDM measurements were made today because of persistent low cloud and rain. Seven GPS lines were measured today across the northern and eastern areas of the volcano and the data is still being processed.

Observations of the volcano from the ground and the helicopter have been possible at times during the day. Many rockfalls were observed today and most of these were concentrated in the northeast of the dome. Vigorous steaming was seen from various parts of the dome, especially the south dome.

The level of activity at the Soufriere Hills volcano is still very high and scientists continue to view the situation with grave concern. The MVO continues to urge that visits to the evacuated zone are kept 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