Montserrat Volcano Observatory

Daily Report
Report from 16:00 on Saturday 13 April
to 16:00 on Sunday 14 April 1996

During this period several small explosions and occasional rockfalls have occurred, and there has been a continuation of the intense hybrid seismicity observed since Tuesday. The most notable events were a series of rockfalls and small explosions that started at 20:37 last night (Saturday) and continued for 25 minutes. Further small explosions occurred at 00:52, 03:38 and 08:00 today (Sunday). The event at 08:00 produced a moderate ash cloud, and several smaller ash clouds developed from rock falls later in the day.

The number and size of the repetitive hybrid earthquakes decreased following these rockfall events. However during Sunday the number of hybrid earthquakes has increased again to about three per minute.

Visual observations have been restricted by the low cloud today. During the morning, some views were obtained from Whites, and it was confirmed that the recent spine is still present. However, some of the spine has collapsed, leading to a spiky top surface.

EDM measurements were made of the eastern triangle, between points in Long Ground, Whites and on Castle Peak. The measurements show that Castle Peak has moved by only a few millimetres over the last two days, consistent with the long-term trend of movement of 1 mm/day that has continued since mid-November 1995.

Global Positioning System (GPS) measurements were made at points in the northern web, extending from Tar River round to St George's Hill. A problem with the battery at one station meant that all the measurements could not be completed. Over the next few days, the northern web will be remeasured to determine accurately the distances between the points in the web. Subsequent measurements over the coming weeks will determine the amount of deformation associated with the current volcanic activity.

The situation at the Soufriere Hills volcano remains highly dangerous, and further major explosive activity could commence with little warning. Therefore, the MVO scientists continue to urge that visits to the evacuated zone are kept to a minimum. The Tar River, Long Ground and Whites areas remain very dangerous, and people are advised not to enter these areas under any circumstances.

Montserrat Volcano Observatory