Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 27 April
to 16:00 28 April 1996

Activity at the Soufriere Hills Volcano during this period has been dominated by persistent rockfalls from the eastern and northeastern sectors of the growing lava dome into the Upper Tar River Valley area. This has resulted in the generation of many ash clouds which have been blown on the wind towards the west-south-west. A relatively small amount of this ash was deposited in the Upper Gages, Amersham and Kinsale areas while the bulk of it seems to have been carried out to sea.

Seismic activity has been characterised by near-continuous low to moderate amplitude broadband tremor recorded at the closest seismic stations. Many small to moderate sized signals interpreted as rockfalls have been recorded, the largest of which occurred at 07:09 on 28 April. This event generated a small pyroclastic flow into the Upper Tar River Valley area. Very few of the hybrid earthquakes seen during the past several weeks were recorded.

John Stix and Pierre Delmelle arrived on the island late yesterday 27 April to carry out gas monitoring. Six Correlation Spectrometer (COSPEC) runs were made today from a jeep on the roads around Plymouth. The quality of the data is good and the preliminary results indicate that the level of Sulphur Dioxide (SO2) production is very low. The last COSPEC measurements in Montserrat were made in late August / early September 1995 by the USGS and also indicated very low SO2 levels.

No EDM or GPS measurements were made today.

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