Montserrat Volcano Observatory

Daily Report
Report for the period 4 pm 24 September
to 4 pm 25 September 1997

There have been three more explosions in the last 24 hours. Pyroclastic flows following these explosions travelled down Tar River, Mosquito Ghaut, Tuitt's Ghaut and Gages Valley.

The first explosion was at 5.16 yesterday afternoon and was not preceded by any hybrid earthquakes. The pyroclastic flows travelled down the Gages Valley and Mosquito Ghaut and the resulting ash blew mainly over Plymouth. The second explosion occurred at 03:55 this morning and the pyroclastic flows again went down the Gages Valley. This time there was an extended hybrid swarm which started at about 11 last night. The third explosion again had no prior hybrid swarm. It happened at 10:59 this morning and was accompanied by pyroclastic flows down Tuitt's Ghaut, Gages Valley and to the sea down the Tar River Valley. For the second two explosions the ash came further to the North and fell in occupied areas. In all cases the explosions were followed by an episode of harmonic tremor which seems to correlate with vigorous ash venting seen on the dome.

Over the last 24 hours 47 hybrids, 20 rockfalls, 5 volcano-tectonic earthquakes and 17 long-period earthquakes triggered the seismic network.

More explosions are very likely and these may be larger than before. The pyroclastic flows associated with these explosions may well reach the Belham valley and threaten areas in the exclusion zone. Also, whenever an explosion occurs fallout can be expected anywhere on the island, depending on the wind direction. When this happens it is best to stay indoors and to wear a mask if you must go outdoors. If driving extra care should be taken.

The volcano is in a highly dangerous state and everyone still in the exclusion zone is encouraged to move north as quickly as possible. Those remaining in that area do so at great risk. If the sirens sound, move north and to higher ground immediately, taking a hard hat or cushion for protection from falling clasts.

Montserrat Volcano Observatory