Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 31 August
to 7 am 1st September 1997

Overnight there was some quite vigorous and prolonged rockfall and pyroclastic flow activit. Seismic records have been dominated by rockfall and small pyroclastic flow signals, hybrids and a few long period earthquakes. Minor rockfall activity occurred throughout yesterday evening and picked up about midnight with some larger pyroclastic flow signals and many rockfall events. This enhanced activity has continued through the night. Currently the summit of the volcano is shrouded in cloud.

The recent pyroclastic flow activity has produced further significant changes on the northern flanks of the volcano. Mosquito Ghaut was filled almost completely and an erosion gully was cut in the flow deposits immediately beneath the active dome. This new channel fed pyroclastic flows in the late afternoon across the Farrels Plain to the north-west rather down the infilled Mosquito Ghaut. Larger flows may thus extend into the Belham Valley by this route or by flowing down the Gages valley and around St Georges Hill.

Explosions may take place with little or no warning and may be more intense and longer lasting than those which occurred earlier this month. If an explosion does occur, small rocks and ash can be expected to fall everywhere on the island. People should 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.

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. Access to the exclusion zone is completely restricted. Access to areas south of the Nantes River is allowed during the day, but only for essential visits. Everyone should remain vigilant and listen to Radio Montserrat.

Montserrat Volcano Observatory