Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 05 November
to 16:00 06 November 1996
The current alert level is ORANGE.

The level of seismic activity at the volcano has decreased slightly, and the volcano-tectonic earthquakes have almost stopped. There have been several moderate rockfalls this afternoon, which suggest that the eastern face of the dome has become active once again.

The volcano tectonic earthquake swarm which began in the evening of 3 November has died out, with only a few earthquakes being recorded this afternoon. A total of 67 VTs were recorded during the 24-hour period, and these were located at shallow depths beneath the crater. Six rockfalls and 2 long-period earthquakes also occurred. Some of the rockfalls this afternoon were larger than those recorded recently, and one signal was associated with a moderate-sized rockfall seen on the eastern face of the October 1 dome. This slight increase in the rockfall activity indicates that the dome growth rate may have increased again.

The viewing conditions were moderate this morning allowing observations to be made from the helicopter. No major changes were seen from yesterday, although the spine on top of the October 1 dome seems to be slightly larger. A landslide has occurred from the wall above Galways Soufriere. The vegetation on this wall has been destroyed by the volcanic activity, allowing the soil to be loosened by recent rain. The rock which forms the interior of the wall remains solid. The top of the October 1 dome was 880 metres (2875 ft) high yesterday.

EDM measurements were completed today on the eastern triangle. The measurements made yesterday and today show a continuation of the long-term shortening of the lines to Castle Peak, of about 1 cm per day.

A GPS survey was made of the western network, which comprises five stations on the western side of the volcano. The measurements were completed successfully, but the results are not available yet.

No COSPEC runs were made today. Yesterday's readings gave a sulphur dioxide flux of 155 tonnes per day, which is quite a bit lower than recent measurements.

The scientific team at the MVO remain highly concerned about the high level of seismic activity during the past few days. However, the scientists cannot be sure that the earthquake swarms will lead to a potentially dangerous volcanic explosion in the near future. We advise that the alert level remains at Orange and that it may be a few days before the alert level can move down 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.

Montserrat Volcano Observatory