Montserrat Volcano Observatory

Daily Report
Report for the period 5 p.m. 28 September
to 5 p.m. 29 September 1998

The level of volcanic activity increased slightly again today. A total of 22 rockfalls and 14 volcano-tectonic earthquakes were recorded by the seismic network in the past 24 hours.

Overnight there were several rockfalls that generated small ash clouds and between 11pm and 1am there was a period of low amplitude tremor. This correlated with roaring sounds from the volcano and a period of ash venting. Winds were blowing to the north and fine ash from the venting and rockfall activity was deposited across the north of the island.

Since about 11am this morning continuous harmonic tremor was recorded by the seismic network. The tremor was ongoing at the end of the reporting period and appeared to correlate with vigorous ash venting on the northern slopes of the dome. The venting produced a low ash cloud which drifted to the north west at up to 4000ft.

Almost clear conditions enabled scientists to make a survey of the dome today from four different sites including Chances Peak and Perches Mountain. This survey will be used to assess the volume of the dome remaining at the present time.

Residents of Montserrat should continue to check Radio ZJB in case of further sudden developments in the state of the volcano.

Montserrat Volcano Observatory