Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 13 November
to 16:00 14 November 1996
The current alert level is ORANGE.

Activity at the volcano has been at an increased level over the past 24 hours. The crater has been clear today for the first time for a while so some good views of the dome were obtained. Even though still relatively quiet, the scientists remain highly concerned about the possibility of dome explosions from the volcano.

Seismic activity during the period has included the return of volcano-tectonic earthquakes. Thirty one vts were located during the reporting period, mostly located at shallow depths beneath the crater. However, several events were located to the southeast of the volcano. Four rockfall signals triggered the seismic network during the period, the largest at 00:17 this morning. Two long period earthquakes were also recorded. Two periods of high amplitude tremor were recorded on the Gages seismic station, between 17:00 and 19:45 last night and between 05:42 and 09:30 this morning. Both periods are probably indicative of increased steaming from the crater.

The viewing conditions at the volcano were better today, and observations from the helicopter and White's Yard were possible. Some new growth of the dome was observed on its northern side, with fresh light grey dome rock at the surface. Steaming was seen mainly from the area around Castle Peak. Some rock avalanches continue to occur from the southern side of the Galways Wall although they are quite small at the moment. However, the upper part of the wall is becoming somewhat unstable.

EDM measurements were carried out today on the eastern triangle - the Long Ground and White's to Castle Peak lines both showed a shortening of c. 2.5 cm over the past 6 days, a slight reduction from the trend established over the past few months.

The COSPEC instrument recorded a total sulphur dioxide flux of 243 tonnes per day today, which is slightly higher than the level over the past few days.

Today was busy in terms of staff movements at MVO, with Ms Nicki Stevens, Dr Paul Cole and Richard Robertson all leaving Montserrat after between 5 and 10 weeks on island each. Staff at MVO wish to thank all three departing scientists, especially Mr Robertson, whose efforts as Chief Scientist have been greatly appreciated by all. Dr Simon Young takes over as Chief Scientist for the next 2 months or so. Prof Steve Sparks is due to arrive back on island later this afternoon for a one month tour of duty.

Scientists at MVO remind everyone that the volcano is still in a very dangerous state and all residents should follow the recommendations laid out in the alert procedures and listen to Radio Montserrat. The volcano has not behaved in this way before and is thus unpredictable, hence the high concern level amongst the scientists. A rapid escalation to explosive activity is possible at any time and citizens are reminded not to become complacent. The Tar River and Long Ground areas remain especially dangerous and anyone entering these areas is putting themselves at risk of death.

Montserrat Volcano Observatory