Thirty-three (33) earthquakes have been located during this period. Almost all of the events were located beneath the Soufriere Hills Volcano, in the depth range 0-5 km (i.e within 3 miles below the surface). The number of recorded earthquakes has continued to decrease following the peak period of Nov 14-15.
Tar River, Galway and O'Garra EDM lines were measured today. The Tar River line shortened by a small amount. All the other lines showed essentially no change from their previous measurements.
The GPS (Global Positioning System) points were measured again last night. The results of yesterday's measurements showed almost no change from the measurements made on the 15th. A GPS point has been established on Chance's Peak today, to measure the distances between the points at Chance's Peak, Tar River and St. George's Hill. The results of these measurements will be presented tomorrow.
Observations of English's Crater were made this morning from Chance's Peak, for the first time since 14 November. A landslide has occurred at the edge of the July 18th vent, which has partially filled the vent with rocks. It was confirmed that the recent sharp change in activities was due to an upward extension of the dome that formed in September. The dome also appears to have extended slightly towards Chance's Peak. The two vents between Castle Peak and the dome were steaming vigorously.
The activity we have observed recently is likely to continue. Scientists shall continue to maintain the same level of vigilance in monitoring.
Dr Joseph Devine from Brown University, Rhode Island, USA, left the island this morning after spending ten (10) days. He is one of the resource persons who is conducting tests on the ash samples. This was his third visit to Montserrat since the crisis began.
Note: The processing of the earthquakes that occurred on 14 and 15 November has been completed. A total of 263 earthquakes were located during the period 16:00 on 14 November to 16:00 on 15 November.