Montserrat Volcano Observatory

Morning Report
Report for the period 4 pm 12 October
to 7 am 13 October 1997

The 49th explosion of the current series occurred at 10:24 last night. Due to the low cloud, the height of the eruption column was not known but winds seem to have carried most of the ash fallout away from Montserrat towards the east. Incandescent pyroclastic flows and surges moved down most flanks of the volcano, with distinct flows in Gages to the base of St George's Hill, in Tyer's Ghaut to the Dyer's area and down Tuitt's Ghaut. Flows did not reach further than during previous events, but continued filling of the ghauts means that big flows will be able to travel further.

Seismic activity has been generally low, although there were a few hybrid and vt earthquakes prior to the explosion and a period of tremor related to ash and steam venting for about an hour after the explosion. Since that time there have been several rockfall signals recorded on the seismic ne twork.

Further explosions are expected during today and, although these will probably be similar in size to those experienced already, longer explosions fuelling more vigorous pyroclastic flows are a distinct possibility. No warning is expected before further events. All residents remaining in Frith, Old Towne and Salem are thus urged to move out as soon as possible.

After an explosion, fallout can occur anywhere on the island. People should shelter in a strong building and wait for the fallout to end. If this is not possible then hard hats or other suitable protection should be worn. Avoid driving during or immediately after ashfall if at all possible. The roads are very wet this morning and drivers should be very careful as where there is ash still on the road, it is very slippery. 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