Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 13 May
to 16:00 14 May 1996

Activity at the Soufriere Hills Volcano during the night and up until about 08:30 today has been higher than yesterday. Seismicity continues to be dominated by small- to moderate-sized rockfalls. Seismic signals recorded at 01:11, 02:45, 05:35, 08:02 and 11:36 were probably associated with pyroclastic flows in the Tar River Valley area. The flows for the events of 05:35, 08:02 and 11:52 were observed from Bramble Airport. None of these pyroclastic flows were as large as the largest events on Sunday 12 May. The rockfalls and pyroclastic flows were associated with ash clouds which were blown on the wind towards the west , depositing ash in Plymouth and surrounding areas. A sequence of rockfalls which began at 08:02 generated an ash cloud which was estimated to reach a height of about 6,000 ft above sea level. There were fourteen long period events and two V-T's during the period. Both V-T's were located beneath the Soufriere Hills Volcano.

Visibility throughout most of the day was generally poor with low cloud cover obscuring the volcano. Despite the poor visibility brief views were obtained of the lower parts of the dome from several areas around the volcano. Some of the early morning rockfalls and pyroclastic flows were observed from the Airport to occur from the north-eastern parts of the dome.

Low cloud cover once again prevented completion of measurements along the Eastern EDM triangle. GPS measurements were conducted on both the MVO and University of Puerto Rico's network. The results are still being processed.

Further COSPEC measurements were made today and the data is still being processed.

Residents of the areas which continue to be affected by the recent ashfalls are again advised to wear dust masks when outside or when cleaning up ash inside. More ashfalls from rockfalls and possible pyroclastic flows in the Tar River Valley area should be expected. The areas affected would obviously depend mainly on the direction of the wind.

The present level of activity at the Soufriere Hills Volcano continues to cause concern to the scientists. The MVO urges that visits to the evacuated zone are kept to a minimum. Given yesterday's events in the east, it is important to again emphasize that the Tar River, Long Ground and Whites areas are extremely dangerous and should not be entered under any circumstances.

Montserrat Volcano Observatory