Volcanic activity at the Soufriere Hills volcano during this period continued at the same level as yesterday. Seismicity continues to be dominated by small-sized rockfall signals.
There were 8 long-period events and no VT earthquakes recorded by the seismic network today. The small hybrid events which started to appear on the Chances Peak seismograph on 18 May declined in number, and slightly in size, at about 08:00 on 21 May. Since then they have been recorded at a rate of about one or two per minute.
The continuous low-amplitude broadband tremor which has been recorded on the Gages seismograph since 13:30 on 20 May increased in amplitude at about 19:00. This episode lasted until about 22:00, when the tremor became more intermittent. Low-amplitude intermittent tremor was recorded throughout the rest of the reporting period.
Visibility was poor, and the dome was covered in cloud all day.
No EDM measurements were made due to the poor visibility. The GPS receivers were deployed at Harris's Lookout and Broderick's all day in order to determine accurate positions for these stations, which are used as reference stations in the MVO GPS network.
Further gas measurements were made using COSPEC. This data has not yet been processed. The data from yesterday shows an SO2 flux of about 160 tonnes per day, consistent with previous low results.
Ellen Howell and Michael Nolan of the University of Puerto Rico left Montserrat today, at the conclusion of this phase of their GPS project. They will be carrying out further processing of the data. Lloyd Lynch of the Seismic Research Unit arrived today for a brief fact-finding visit.
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. The Tar River, Long Ground and Whites areas are extremely dangerous and should not be entered under any circumstances.