Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 3 December
to 6 pm 4 December 1997

Seismicity has remained at a relatively low level today with mainly rockfall signals being recorded. Visibility today was good.

Between 16:00 yesterday and 16:00 today there were 41 long-period earthquakes, 103 rockfall signals, and 8 hybrid earthquakes. Good views of the dome were obtained today. The northern lobe of the October 22nd dome appeared not to have changed since it was last seen and only a few of the rockfalls were being generated from this portion of the dome. On the southern side the Galways area has changed significantly. Rockfall activity over the last two weeks has built up and extended the talus slope southwards and westwards. The southern lobe is now significantly wider and taller than the northern lobe and is beginning to encroach on Chances Peak. Rockfall activity in the Galways area is fairly continuous this is still where the active growth is concentrated. Although activity is still mainly focused on the southern side of the volcano, past experience has shown that the area of growth on the dome can change very quickly and pyroclastic flows could occur down any of the ghauts around the volcano with little or no warning.

Average dust levels over the last 24 hours in St. Johns, St. Peters and Woodlands were low.

Electronic Distance Measurements were made on the Old Towne, Garibaldi Hill and Lees triangle today and the data are being processed.

Montserrat Volcano Observatory