Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 19 July
to 7 am 20 July 1997

The alert level system has been revised by zones

Activity at the volcano overnight has been at about the same level as yesterday. Rockfall signals of small to moderate amplitude were the main type of seismic events recorded by the seismic stations. Two periods of low to moderate amplitude tremor occurred on both the St George's Hill and St Patrick's seismometer during the early morning; between 12:13 to 12:26 am and 1:08 to 1:25 am. These were most likely due to mudflows, possibly in Fort Ghaut or Aymers Ghaut, caused by remobilisation of recent deposits by the heavy rain experienced yesterday. The Chances Peak tiltmeter does not currently show any obvious cyclical behaviour but the long term deflationary trend has continued, although at a lower rate. Further rockfalls and moderate pyroclastic flows can be expected later today, and may occur in any direction at any time.

The volcano is overcast this morning and no views were possible of the summit.

The current area of activity in the crater still makes Mosquito Ghaut and Gages the most likely pathways for pyroclastic flows and surges, but further flows in Tuitt's or Tar River are possible. The Belham River valley is also dangerous and should not be entered. Access to the exclusion zone is completely restricted, and people should stay completely away from the flanks of the volcano. Everyone should continue to stay alert, and listen to Radio Montserrat for any announcements.

Montserrat Volcano Observatory