Montserrat Volcano Observatory


Morning Report
Report for the period 4 pm 8 September
to 7 am 9 September 1997


There has been continued pyroclastic flow activity on the northern flanks of the volcano both yesterday evening and overnight. At least two pyroclastic flows occurred overnight at 0233 and 0345. Incandescent material was observed from MVO as flows travelled down Mosquito Ghaut. Runout distances for these flows have yet to be confirmed

The collapses were preceded by a swarm of hybrid earthquakes which lasted from 0154 to 0320 and consisted of 37 events. Intervals between the hybrid swarms over the past three days have remained constant at around 12 hours, suggesting a 12 hour period to the volcanic activity at the moment. Given the size of the dome further collapses are likely and these may take place with little or no warning.

Pyroclastic flows can now get into the Belham Valley freely and the next collapse may send pyroclastic flows to the Belham Bridge and beyond. Topography suggests that the Belham valley may be quickly filled with deposits allowing flows to impact upon Old Towne and Friths areas and associated surges could get to Salem. With pressurisation of the dome and collapses, the possibilities of explosive events is increased. The southern part of Montserrat is thus extremely dangerous and all areas south of the Nantes River should be evacuated. All residents of Montserrat should be vigilant and listen to Radio Montserrat for further information.


Montserrat Volcano Observatory