Volcanic activity at the Soufriere Hills volcano has been at a moderate level today, dominated by rockfalls, a few small ash clouds and a lowering of the rate of hybrid earthquake activity.
Seismicity has been dominated by the occurrence of rock fall signals, the largest being at 21:48 on 2 June and 01:41, 13:37 and 15:35 on 3 June. A total of 58 rock fall signals were recorded by the network today, a somewhat reduced level from the past few days. The small hybrid earthquakes which had been present for the several days died away early this morning, synchronous with a 2-hour period of broadband tremor on the Gages seismometer probably generated by water movement in Fort Ghaut.
There was a single, large hybrid event but no VT earthquakes recorded during this period. Intermittent low-amplitude broadband tremor continues to be recorded on the stations nearest the crater.
Viewing conditions have been very poor throughout the day and only brief glimpses were obtained of the eastern parts of the dome. No major changes were apparent; the small whaleback' feature noted yesterday is still present and appears to have undergone very little change. Two radial features located to the north of the whaleback and on the eastern side of the dome, were also observed. Small ash clouds generated by rock falls were seen during the day, drifting on the prevailing light winds to the west over the Gages and Upper Amersham areas and producing light ashfall at times.
Low cloud cover continued to prevent full measurement of the Eastern EDM Triangle to Castle Peak. However, a limited number of measurements were made and suggest little or no change from yesterday. No GPS measurements were made today due to continued technical problems.
COSPEC measurements of SO2 gas concentration in the volcanic plume were made along the coastal road in Plymouth today. The results of these measurements indicate an SO2 flux of about 195 tonnes per day, the same as yesterday within the error of the technique, continuing the slight increase over measurements from the past few weeks.
Mr Wilkie Balgobin of SRU returned to Trinidad yesterday after completing his tour of duty. Mr Jean Battaglia, attached to the Guadeloupe volcano observatory, arrived today; he will be undertaking gas measurements at the soufrieres around the volcano.
The current volcanic activity at the Soufriere Hills volcano remains highly dangerous. The MVO therefore urges that visits to the evacuated zone are kept to a minimum. The Tar River, Long Ground and Whites areas are extremely dangerous and should not be entered under any circumstances.