Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 23 October
to 16:00 24 October 1996
The current alert level is AMBER

The volcanic activity has remained at about the same level during the past 24 hours. There was a swarm of volcano-tectonic earthquakes during the night, and several rockfalls from the October 1 dome have also been recorded. No views of the crater were possible.

The swarm of volcano-tectonic earthquakes occurred between 20:47 last night and 03:30 this morning and contained 25 events. These were located at shallow depths beneath the crater area. One other VT earthquake was recorded, along with two long-period events. There have also been two regional earthquakes. A location to the east of Barbuda was determined by the Seismic Research Unit in Trinidad for one of these earthquakes.

There were nine rockfalls signals during the period, a slight decrease in numbers since yesterday. Most of the rockfalls occurred overnight, and the volcano has been seismically quiet since 10:00 this morning. Broadband tremor has been recorded at the Gages seismic station at a slightly higher amplitude this afternoon.

The viewing conditions have been poor today, and no observations or EDM measurements were possible. Work has continued at the Observatory to process recent GPS, COSPEC and dome volume measurements. Preliminary results show that the volume of the October 1 dome was almost 5 million cubic metres on 18 October. This indicates an average growth rate of about 3 cubic metres per second for the first two weeks of October.

COSPEC measurements were carried out today to measure the levels of sulphur dioxide coming from the volcano. There is still a small problem with the instrument, and so the results measured yesterday and today are not yet available.

The volcano remains in an active and highly dangerous state. Further activity, possibly leading to an explosive event could occur with little warning in the near future. Everyone who enters the evacuated zone must remain alert and be ready to move at short notice. Individuals who go beyond the Long Ground area into the Tar River valley are risking death.

Montserrat Volcano Observatory