Activity at the Soufriere Hill volcano increased slightly today. At 0916 there was a collapse of material from the dome. The ash cloud from this event rose to around 7000 feet and moved to the west across Plymouth. The exact direction of the collapse remains uncertain because of low cloud which hampered visual observations. In keeping with recent events, the collapse was followed by a period of volcanic tremor which lasted for several hours.
The collapse was immediately followed by a swarm of volcano-tectonic earthquakes. Many of the earthquakes were large and there was at least one report of an earthquake being felt. The swarm began at 1316, lasted almost 5 hours and contained 47 earthquakes. Locations for many of the earthquakes were found to be slightly to the south of the volcano.
For the rest of the reporting period the seismic activity was low. Over the 24 hour period from 16:00 yesterday, 53 volcano-tectonic earthquakes and 10 rockfalls were recorded on the seismic network.
Residents of Montserrat should continue to check Radio ZJB in case of sudden developments in the state of the volcano.