Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 24 April
to 16:00 25 April 1997
The current alert level is AMBER

The level of rockfall activity has been at a lower level in this reporting period than over the previous two days, and ash generation has thus been more limited. The level of seismicity remains relatively low.

The broadband seismic network recorded 86 rockfall signals during the past 24 hours. This is a marked reduction from yesterday but is still a relatively high level. 27 long-period earthquakes were also recorded, over half of these preceding rockfalls. No other types of seismic signal were recorded. As has been seen previously at the volcano, seismicity can be at a relatively low level for short times during periods of dome growth, and will probably increase again.

Visibility today has not been as good as in recent days, and the upper parts of the dome were not seen. Rockfall activity appears to be confined to the southwestern part of the dome in the area above Galway's Soufriere, and ash generated from these rockfalls has been blown over the Plymouth area by the southeasterly winds. Ash fall has been generally light, but the continued dry conditions means that lots of ash is being remobilised, making the atmosphere very ashy.

No GPS or EDM surveys were carried out today, although processing of a GPS survey from earlier in the week was completed. This showed no significant movement of the Farrell's pin, confirming the EDM survey of earlier in the week.

The alert level is Amber. The reduction in rockfall activity today may only be temporary, and some ash fall can be expected in any areas downwind of the volcano over the next few days. The Tar River and White River valleys are extremely dangerous, and should not be entered under any circumstances.

Montserrat Volcano Observatory