Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 16 January
to 16:00 17 January 1997
The current alert level is ORANGE

Rockfall and pyroclastic flow activity from the dome has continued during the past 24 hours, at a lower level than the first half of this week. There has also been some volcano-tectonic and long period earthquakes. Visual inspection of the crater area throughout the day revealed that the scar left by yesterday's pyroclastic flow is being filled with new material.. The south-eastern part of the dome remains in an unstable state, and further pyroclastic flows are likely in the next few days. A major collapse of the dome is possible. This could lead to another explosion, similar to that of September 1996. It is however expected that there would be several hours of a high level of pyroclastic flow activity before any explosion. Zone E, which includes Cork Hill and the airport, remains safe.

A total of 48 rockfall signals, 14 long period and 19 volcano-tectonic earthquakes have been recorded in the last 24 hours. Most of the volcano tectonic events were recorded during a swarm which lasted from 10:26 pm to 11:07 pm last night (16/01/97). These events were located at shallow depth beneath the crater.

Today, the dome was inspected from the ground at Whites and from the helicopter. During the early morning flight the scar left by yesterday's pyroclastic flow seemed to have stabilised but by this afternoon it became partially filled with new slabs of material that extruded from the upper boundary. Most of the small pyroclastic flows that were observed today originated near this scar and travelled down the chute eroded by the previous larger flows into the upper reaches of Tar River.

The Big GPS network was reoccupied today. This network encompasses the stations at the lower flanks of the volcano. The results are not yet available. No COSPEC measurements were taken today.

Montserrat Volcano Observatory