Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 29 October
to 6 pm 30 October 1997

The volcano today has been dominated by swarms of hybrid earthquakes and rockfall signals.

Observations of the 22 October dome made today confirmed that it is continuing to grow rapidly although perhaps not at the rate observed in the first few days. The small, stubby spines which were seen yesterday were still present today and the dome still has a relatively flat upper surface, but the northern slope is very steep and unstable. Measurements of the top of the dome were not possible today due to poor viewing conditions, but brief glimpses indicate that there may have been some growth since it was last seen. Several small rockfalls were observed being generated from the new dome during most of today and material from small pyroclastic flows travelled into the upper reaches of Tuitts Ghaut. Rockfalls were seen in the Galways area. It is almost certain that as the dome continues to grow pyroclastic flows will be generated, these are most likely to travel down Tuitt's Ghaut. Rockfalls from older dome material could, however, also occur in any of the ghauts around the volcano.

Seismicity has been dominated today by hybrid earthquake swarms. The first one occurred between 11:53 last night and 1:06 am this morning, the second swarm between 6:19 and 7.58 this morning and the third swarm occurred between 12:45 and 3:35 this afternoon. Overall between 4pm yesterday and 4pm today there have been 139 hybrids, 26 long period earthquakes, 6 of which were followed by rockfalls and 61 rockfalls. This is a general increase in the number of earthquakes since yesterday.

Friths, Old Towne and Salem are not safe with activity in its current state. Anyone remaining in these areas is strongly urged to move out of the exclusion zone. Ash levels in inhabited areas are currently low and do not present a health risk. Ghauts leading away from the volcano are especially dangerous because of the possibility of hot mudflows travelling down the valleys after heavy rainfall in higher regions. Stay tuned to Radio Montserrat for further information.

Montserrat Volcano Observatory