Montserrat Volcano Observatory

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

Since 4pm yesterday afternoon there have been two explosive events at the volcano. The first explosion occurred at 11.03pm, over 12 hours after the previous event and the second event was at 6.36 this morning.

Observations of the event last night indicated that pyroclastic flows travelled down the northern flanks of the volcano and into Gages valley, further observations during the course of the day will establish the extent of these flows. The ash column rose to well over 10,000ft and there was sand-sized fallout in Salem and fine ashfall in the Woodlands area. There were several hybrid earthquakes in the hours before this eruption, but not enough to constitute a swarm.

This mornings audible explosion generated a very dilute and steam-rich plume which just reached about 10,000ft in altitude. The ash cloud was blown west over Plymouth and the Foxes Bay area, there was no fallout on the inhabited parts of the island. Pyroclastic flows generated by this event travelled across the eastern part of the Farrells plain and probably into Gages Valley. The ash venting following this eruption was not particularly vigorous and the resulting ash column only reached heights of about 1000ft above the vent. Several hybrid earthquakes occurred in the early hours of the morning before this event, but again they did not constitute a swarm.

Further explosions are very likely and these could be bigger than those experienced in the last few days. Pyroclastic flows could reach the Belham valley and an event directed down the Belham valley of a similar size to the one last Sunday morning, which destroyed the airport, would reach the Belham bridge and impact upon Frith and Salem. All those remaining in the exclusion zone are urged to leave as soon as possible.

When explosions happen fallout may occur anywhere on the island, so hard hats or other suitable protection should be worn. Preferably, people should seek shelter in a sturdy building and wait for the fallout to end rather than trying to move or drive anywhere during the fallout period. Falling ash and pumice reduces visibility and makes driving conditions extremely hazardous. The pumice and coarse ash deposited over the previous few days has made many roads very treacherous. Plenty of time should be allowed for any journey and drivers should be very careful. The wearing of ash masks is recommended at all times. Everyone is advised to keep listening to Radio Montserrat for information on the activity.

Montserrat Volcano Observatory