Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 20 November
to 16:00 21 November 1996
The current alert level is AMBER

Activity at the volcano was at a higher level during the past 24 hours than over the past few days, with the anticipated increase in rockfall activity accounting for this higher activity level.

A total of 12 rockfall signals triggered the seismic networks today, with the largest occurring within an intense period of activity between 02:09 and 02:54 this morning (21 November). Other rockfalls this morning produced some small amount of ash which, due to the very still conditions, did not travel far from the crater area. There have been just 2 VT earthquakes recorded by the seismic network today. Both earthquakes were at shallow depths beneath the crater. Two long-period earthquakes were also recorded during the reporting period.

Visibility was good for a short interval this morning but remained poor for much of the rest of the day. Views of the dome from the ground suggested that it is continuing to grow, although the rate of growth remains difficult to estimate until a volume survey is possible. The number of rockfalls generated today may indicate that dome growth is quite rapid at present.

No EDM measurements were carried out today because of poor visibility in the east. The wind direction and strength made COSPEC measurements impossible again today.

The results from the GPS survey on the volcano-wide network undertaken yesterday showed no movement of the flanks of the volcano. Dr Ricky Herd, chief GPS operator at present, was reportedly very pleased with the data quality for the survey, and it is encouraging news that no major swelling of the volcano is taking place.

The volcano remains in a dangerous state. Continued dome growth means that rockfall activity is likely to increase over the next few days to weeks, and there may be pyroclastic flows into the Tar River Valley. These will generate ashfall downwind of the volcano. A rapid escalation to explosive activity cannot be ruled out. The Tar River and Long Ground areas remain especially dangerous and anyone entering these areas is putting themselves at risk of death.

The MVO Tremors won the first match of the Carib Montserrat National Football League yesterday afternoon 3-2 against Police. Goals by Pops Morris and Andy Sparks clinched victory and captain, Leroy Luke, was said to be pleased with the performance.

Montserrat Volcano Observatory