Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 26 February
to 6 pm 27 February 1998

Volcanic activity has been at a lower level than yesterday but continues to be dominated by hybrid earthquakes and rockfalls signals. Ash and steam venting continues to be vigorous but dust levels at all monitoring sites are low.

There were 43 hybrid earthquakes, 1 volcano-tectonic earthquake, 3 long period earthquakes and 32 rockfalls signals recorded between 16:00 yesterday and 16:00 today. One earthquake swarm occurred between 09:12 and 11:05 this morning and consisted of 24 hybrid earthquakes. The seismic recordings reached a peak amplitude between 10:00-12:00 during which time a moderate pyroclastic flow occurred down the southern flanks of the volcano. Increased ash venting also was observed during this period and there was light ash fall over Plymouth. The ash plume continued to drift west throughout the afternoon.

Clear views were obtained of the volcano during the late afternoon. The summit of the new dome now extends above the dome complex and consist of several large blocks. Vigorous degassing appears to be concentrated at the back of the scar in the northern parts of the new dome with the top parts of the dome complex in the Tar River area also steaming. The dome is now separated from the Tar River valley by a very thin shoulder which may be overcome by rockfalls from the new dome in the next few days.

Dust levels at all monitoring sites were again low today. A new dust monitoring site has been established in Old Towne.

Residents are reminded to remain alert and listen to ZJB radio.

Montserrat Volcano Observatory