Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 12 December
to 6 pm 13 December 1997

The volcanic activity is once again at a relatively low level, with rockfall signals being the dominant activity on the volcano.

Between 16:00 yesterday and 16:00 today, the broadband seismic network recorded 109 rockfall signals, 17 long period and 18 hybrid earthquakes. This activity is still consistent with continuing dome growth.

Good views of the dome were obtained late this afternoon. Small rockfalls have begun to occur down the Tar River side of the dome. Continuous small rockfalls were seen down the Galways side and the main active growth area is concentrated high up on the Galways sector of the dome. Production of diffused ash clouds were again seen throughout the day from the rockfalls.

A survey of the dome was achieved today from sites on South Soufriere Hills and on the North bank of the White River. These data are being processed and will be available in a later report.

A new repeater station was installed on Silver Hills today which means that the Long Ground short period seismic station is now back on stream. That repeater site is also potentially an ideal site for receiving signals from other short period seismic stations on the eastern side of the island and the broadband network.

Dust levels in St. Johns, Woodlands and St. Peters today were low.

Although activity is still mainly focused on the southern side of the volcano, past experience as well as recent observations shows that the area of growth on the dome can change very quickly. Growth activity appears now to be backing up behind the major build-up of material in Galways, and rockfalls or pyroclastic flows starting to occur down Gages or Tar River in the near future would not be a surprise.

Chandranath Ramsingh and Sayadul Arafin from the Seismic Research Unit in Trinidad left the Montserrat yesterday after a one month stint at the Montserrat Volcano Observatory.

Montserrat Volcano Observatory