Montserrat Volcano Observatory


Morning Report
Report for the period 16:00 22 April
to 07:00 23 April 1997
The current alert level is AMBER


Volcanic activity continued at a moderate level overnight. There have been a number of rockfall and small pyroclastic flow signals. Flows have been moving down the White River valley. There have also been a number of small long-period earthquakes as have been seen at levels somewhat above background over the past week or more. A number of the rockfalls appear to have been preceded by long period earthquakes.

The length of runout of the pyroclastic flows is currently unknown and will be investigated this morning. Ash generated from these flows has been forming a continuous plume which was distributed to the west at about 5,000 ft overnight but which has swung around to the northwest this morning. Thus ash generated from rockfalls and pyroclastic flows during today may fall on areas of St George's Hill, Cork Hill and Old Towne. Any ashfall is expected to be light.

The increase in rockfall activity is a result of a large number of small collapses from the active part of the lava dome above Galway's Wall. Despite today's lowering of the alert level to Amber, the volcano remains in a dangerous state and rapid changes in level of activity are still possible. All citizens of Montserrat are requested to stay alert, especially when in Zone C. Ash masks should be worn in ashy environments; this is particularly important in the current dry conditions. All of Zone A, which includes Long Ground and St Patrick's, is still very dangerous and should not be entered under any circumstances.


Montserrat Volcano Observatory