Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 6 September
to 7 am 7 September 1997

Activity at the volcano has continued at a similar level to that reported yesterday. Rockfalls and small pyroclastic flows have again been the dominant form of seismic signal but there were also further hybrid and long-period earthquakes overnight. Small peaks in the earthquake activity still appear to be regularly spaced, with the current interval about 10 hours.

The unusual wind direction currently affecting Montserrat again permitted excellent night-time views of the northern and western parts of the dome last night. Activity in the form of rockfalls was observed over almost all of the visible parts of the dome. Small pyroclastic flows were seen entering Mosquito Ghaut and Gages Valley. The wide area of rockfall activity on the dome indicates the dome continues to grow and means a large collapse is possible from a variety of areas.

The summit of the volcano is presently shrouded in cloud. Low level winds are currently from the south-west and the ash-laden steam plume is being carried toward the north-east.

Pyroclastic flows are expected on all flanks of the volcano, and it is never safe to enter the exclusion zone, including the Belham River valley. The size of the dome and the recent filling up of Mosquito Ghaut and the upper parts of Gages by pyroclastic flows make it more likely that large pyroclastic flows can enter the Belham Valley.

Explosions may take place with little or no warning and may be more intense and longer lasting than those which occurred at the beginning of August. If an explosion does occur, small rocks and ash can be expected to fall everywhere on the island. People should then seek shelter under a strong roof and wear a helmet or other head protection. Ash and falling rocks make driving hazardous. Ash will be present in the atmosphere and masks should be worn outdoors.

Access to the exclusion zone, south of the Nantes River, is now completely restricted. Everyone should remain vigilant and listen to Radio Montserrat.

Montserrat Volcano Observatory