Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 28 July
to 7 am 29 July 1997

The alert level system has been revised by zones

Small to moderate sized rockfall signals have been the most common type of seismic signal recorded during the night. Low tremor on the St. George's Hill station has occurred intermittently throughout the night. However at about 6:05 am, the tremor increased in amplitude and moderate pyroclastic flows were generated down Gages Valley. The main signal lasted for about 3 minutes, but elevated tremor continued for over 45 minutes. More pyroclastic flows are likely later this morning. These may not be limited to the Gages valley as the main growth area is over both Mosquito Ghaut and Gages wall. Both of these ghauts are now mostly filled in by rockfall debris and pyroclastic flows are less likely to be confined to the valleys. The pyroclastic flows could occur at any time with no precursory activity.

Low cloud has prevented clear views of the volcano's summit this morning although a thick steam plume is clearly visible drifting to the west of the volcano.

Although the current area of activity in the crater still makes Mosquito Ghaut and Gages the most likely pathways for pyroclastic flows and surges, 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