Montserrat Volcano Observatory


Morning Report
Report for the period 16:00 17 April
to 07:00 18 April 1997
The current alert level is ORANGE


Activity overnight has continued at a similar low level to that of yesterday. Small to moderate sized rockfalls and pyroclastic flows have been the dominant form of seismic signal recorded by the network overnight. Ash clouds generated by these events were blown to the west and north-west by the prevailing winds, and light ash has fallen in Salem this morning. Earthquake activity has been generally low with only one hybrid and some long-period earthquakes being detected by the network. The hybrid earthquake was located beneath the crater at a depth of about 2 km.

Visibility is currently being hampered by low cloud over the crater. The wind is from the south and south-west and so the western flank of the dome can be seen from the observatory. Good views of the Galway's Wall may be obtained later in the day from the new observation post in the South Soufriere Hills. If there is rockfall and pyroclastic flow activity during the day, ash could be transported to the north, and therefore people are advised to carry ash masks with them at all times.

Despite the apparent low level of activity, the volcano remains in an unstable state, with further dome growth in the southern region above the Galway's Wall. Another dome collapse with extensive pyroclastic flows in the White River is expected within the next week. Residents of Montserrat should remain alert, and listen to Radio Montserrat for further updates. Ash masks should be worn in ashy environments. Visits to zone C should be restricted to those that are essential. All of Zone A, which includes Long Ground and St Patrick's, is very dangerous and should not be entered under any circumstances.


Montserrat Volcano Observatory