Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 3 December
to 16:00 4 December 1996
The current alert level is ORANGE

Because of increasing concern over the volcano and particularly the condition of Galway's Wall, the evacuation of Zones A, B , C and D is being strictly enforced. No access is allowed to these zones until further notice.

The level of activity at the volcano has increased further today. The VT earthquake swarm has continued, and several more rockfalls have occurred from the Galway's Wall. A major collapse of the wall could expose hot, gas-rich magma from the lower sections of the dome, and trigger a lateral blast. This has the potential to cause major damage to St Patrick's and the surrounding areas, and the death of everyone in the area. The Tar River and Long Ground areas are still threatened by pyroclastic flows and anyone entering these areas is risking death. Residents of all other parts of Montserrat are reminded to remain vigilant.

An inspection of the Galway's Wall was made from the helicopter this morning. Avalanches had occurred overnight from the wall. Further rockfalls occurred from the western side of the wall this afternoon; one late this afternoon was the largest yet seen from the wall and the rocks reached down to the soufriere area. The wall has many cracks along the top, and is looking increasingly unstable.

The dome has not changed much in the last 24 hours. A small, new spine has appeared at the top of the October 1 dome, and there have been further rockfalls from both the old dome and the October 1 dome. Some significant instabilities have been noted on the older part of the lava dome during the day, increasing the chances of a collapse of the eastern flank of the dome down the Tar River valley.

The VT earthquake swarm which started on 30 November has continued, and intensified slightly. 291 VT events were recorded today, more than yesterday. The current swarm is the most intensive recorded since the start of the eruption in July 1995. The largest earthquakes today were slightly larger than those of yesterday, and there has been as increase in the number of small earthquakes.

EDM Measurements were made today on the lines to Castle Peak. These show an average of 3.8 cm shortening since they were last measured on 30 November. This marks a significant change in the trend seen since July.

Scientists continue to attempt to model possible tsunami hazards should a major avalanche of the Galway's Wall occur. Further information should be available very soon.

Dr Barry Voight and Prof Steve Sparks will give a public lecture on the volcano at the Pelican Room, Vue Pointe Hotel on Thursday December 5, at 7:30 pm.

Montserrat Volcano Observatory