Montserrat Volcano Observatory

Morning Report
Report for the period 6 pm 18 October
to 7 am 19 October 1997

One explosion occurred overnight at the Soufriere Hills volcano. It was at 5:13 this morning and was preceded by a number of volcano-tectonic and small hybrid earthquakes. Very low cloud prevented any sighting of the ash column except at low levels, where ash was blown to the west. The size of the signal on the seismic records suggests that the explosion may have been amongst the bigger ones of this series, and considerably ash was generated from pyroclastic flows on the northern and western flanks of the volcano. In particular, a flow was seen in the upper part of the Belham valley down to the Cork Hill area.

Seismic tremor and steam venting as usual followed the explosion and lasted for about one hour. The volcano is quiet again at the moment.

Further explosions during the day are anticipated, although the interval between explosions is quite variable at the moment so it is difficult to know when the next one will be. Explosions could be bigger and thus more dangerous than they have been so far. 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. Residents are reminded that the flanks of the volcano and ghauts leading away from the volcano remain very dangerous and should not be entered

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 wearing of ash masks is recommended in ashy conditions. Everyone is advised to keep listening to Radio Montserrat for information on the activity.

Montserrat Volcano Observatory