Montserrat Volcano Observatory

Daily Report
Report for the period 6pm 16 April
to 6pm 17 April 1998

The level of volcanic activity over the past 24 hours has remained low.

Between 4pm yesterday and 4pm today 3 volcano-tectonic earthquakes were recorded. There was no significant rockfall activity.

Further work was carried out today on the new broadband seismic stations at Windy Hill, Garibaldi Hill and St Georges Hill. The stations were calibrated and are now producing high quality real-time seismic data.

The line between the reflector positioned on the north crater rim and Windy Hill was measured today using EDM (Electronic Distance Measurement). Shortening on this line has decreased dramatically. Between January 25th and March 17th the line shortened by 83 millimetres, but since March 17th there has been little change. This coincides with the time at which the dome stopped growing. Using GPS it has been calculated that over the last few months Windy Hill itself has maintained a constant position.

Nevertheless, deformation over a wider area continues. A GPS occupation has been made over the last few days of several sites. Long Ground, Whites and a site adjacent to the Tar River valley continue to move to the north east indicating slow deformation over the eastern side of the volcano.

Dust levels at all monitoring stations were low today.

Residents are reminded to keep listening to Radio Montserrat for any further information.

Montserrat Volcano Observatory