Montserrat Volcano Observatory


Morning Report
Report for the period 6 pm 25 December
to 7 am 26 December 1997


Volcanic activity has been high overnight. The swarms of hybrid earthquakes increased during the evening and into the early morning merging into almost continual seismicity at 3.00 am. Preliminary observations indicate that a major pyroclastic flow occurred at this time and was followed by 15 minutes of intense ash venting. The pyroclastic flow appears to have affected the area south of Plymouth in the Gingoes and St Patricks area. The affected areas will be investigated later this morning. The ash venting was accompanied by continuous roaring sounds and lightning in a high ash plume reported to have reached a height of 36,000 feet. The seismicity gradually quietened in the hour following the eruption and has remained low throughout the rest of the reporting period. The volcano appears to have entered into a new phase of activity. Explosions can occur in the days f ollowing a large pyroclastic flow and further pyroclastic flows could occur down any of the ghauts on the volcano with no further warning. Everyone is advised to listen to Radio Montserrat for further information.


Montserrat Volcano Observatory