The level of seismic activity at the volcano has continued to be very low during the past 24 hours. The visibility has been variable with very good views of the crater area obtained during the late evening.
Three volcano-tectonic earthquakes have been recorded during the period; these were located at shallow depths beneath the crater. One moderate-sized rockfall signal and two regional earthquakes were also recorded. A flash flood signal occurred on the Gages station at 11:00 today. Very little tremor was recorded on the Gages station for most of the past 24 hours.
The viewing conditions were variable for most of the day with clear views obtained during the late evening. Excessive amounts of steam were observed over most of the dome complex, particularly in southern part of the new dome where it is in contact with the Castle Peak dome. The northern part of the new dome has several small gulleys where recent rockfalls have occurred; this is the only area from which material has moved recently. The eastern face of the new dome remains inactive. The small spine on the northwestern part of the new dome has partially collapsed and the dome does not appear to have grown very much. Incandescent material was observed on the northern, southern and eastern parts of the new dome.
No EDM or GPS measurements were completed today.
Data recently received for SO2 diffusion tube analyses indicates high concentration of sulphur dioxide for the two week period beginning 17 September 1996. Results from the Upper Amersham site indicate SO2 levels of up to 261.6 ppb (parts per billion). There was good correlation between SO2 diffusion tube analysis and COSPEC results in August and thus, although no COSPEC measurements could be made throughout September and early October, it is likely that the total SO2 flux from the volcano during this period was high.
Despite the current low level of activity, the MVO scientists remain concerned about the possibility of a rapid escalation of volcanic activity during the next few days. Several more days of low activity will be required before we can advise that the alert level can be lowered again. We stress that the volcano is still in a very dangerous state and that all residents should follow the recommendations laid out in the alert procedures, and listen to Radio Montserrat.