Montserrat Volcano Observatory

Morning Report
Report for the period 16:00 4 December
to 07:00 5 December 1996
The current alert level is ORANGE

The intense swarm of VT earthquakes has continued overnight, and further landslides from the Galway's Wall have occurred. The situation remains extremely serious. The Galway's Wall is unstable and collapse may be imminent, leading to a lateral blast. For this reason, absolutely no access to zones A, B, C and D is permitted until further notice. A lateral blast could affect any part of these zones, and occur with very little warning.

A total of 189 volcano-tectonic earthquakes have been recorded since 4 pm yesterday. This is about the same number as during the previous night. The largest earthquakes are still about the same size as yesterday, of up to magnitude about 3 on the Richter scale . Almost 1100 earthquakes have occurred since 30 November. All the earthquakes are at shallow depths beneath the crater, and are thought to be due to magma pressurisation. The increasing numbers and size of the earthquakes indicates that the pressure is still increasing, and this makes the Galway's Wall more likely to fail. The continued earthquake swarm also increases the chances of a vertical explosive eruption.

Visibility is very good this morning and MVO staff will continue their inspections of Galway's Wall and the dome from the helicopter. However, the situation is so serious at the moment that the scientists will make no further trips by road to the south of the island.

Dr Barry Voight and Prof Steve Sparks will give a public lecture at the Vue Pointe Hotel tonight at 7:30 pm. Everyone is invited.

Montserrat Volcano Observatory