Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 1 January
to 6 pm 2 January 1998

Activity at the volcano has been slightly lower than yesterday. There have been several periods of higher level activity throughout the day leading to light ashfall to the west of the volcano.

Between 16:00 yesterday and 16:00 today there were 24 hybrid earthquakes, 8 long period earthquakes, 1 volcano-tectonic earthquake and 45 rockfall signals. Two of the long period earthquakes preceded rockfalls. The rockfalls and hybrids tended to occur in short periods of higher activity approximately 8 hours apart, although the peaks in activity were not as well defined as yesterday. Heavy rain throughout the day led to an increase in seismic activity that was probably related to mudflows down the ghauts around the volcano.

Air quality at all monitoring stations across the island is good today.

Cloud has again covered the top of the volcano all day and so there have been no good views of the crater formed by the Boxing Day collapse. However, preliminary estimates of the volume of material in the White River valley, and hence in the collapse, have been made. These results show that the top of the White River valley outside the crater wall in the area around the Galway's Soufriere has been excavated to produce an amphitheatre approximately 600 m wide from north-west to south-east. A total of 20 million cubic metres of material was removed from this area, and a new soufriere has emerged through the deposits closer to the remains of the Galway's wall. In addition, from brief views of the dome together with estimates of its size before the collapse and the volume of the deposits in the White River valley, it is thought that between 30 and 40 million cubic metres of material was removed from the talus slope and dome during this single event. Examination of the deposits indicate that about 6.7 km2 of south-western Montserrat was affected by a pyroclastic surge that accompanied the landslide.

People should remain alert and listen to Radio Montserrat for further information.

Montserrat Volcano Observatory