Activity at the volcano has remained elevated today. The main activity has been rockfalls and a few small pyroclastic flows in Mosquito Ghaut. Over the last 24 hours 17 hybrid earthquakes, 7 VT earthquakes, 33 long-period earthquakes and 93 rockfalls triggered the broadband seismic network. The long period earthquakes are commonly followed by rockfalls. Cyclic patterns are evident in the data. Rock-fall activity was most pronounced between 1.30 am and 4 am and then from 11 am. At 3.40 pm two detonation sounds were heard associated with a rapidly rising ash cloud and a pyroclastic flow. Peaks in the activity suggest that the time interval between more active periods has decreased to approximately 10 hours. The upper flanks were clear this evening and showed that activity was concentrated in the area above Mosquito Ghaut.
Collapse of material from the dome may lead to further explosions and these may be more intense and longer lived than previous explosions. Explosions are also possible without much warning - as happened in early August. If an explosion does occur, small rocks and ash can fall anywhere on the island. The central zone should be evacuated immediately, and people in the northern zone should seek shelter under a strong roof as soon as possible. Helmets or other head protection should be used and dust masks should be worn outdoors. Ash and falling rocks can make driving hazardous.
Further pyroclastic flow activity is anticipated, possibly without any warning. All ghauts on the volcano are now filled with hot pyroclastic flow deposits and this makes all of the exclusion zone extremely dangerous because the flows will not be confined by the ghauts. The recent changes in Mosquito Ghaut and material accumulating behind St. George's Hill now make it increasingly likely that pyroclastic flows will travel into the Belham River valley from the Gages Valley and from the upper part of Mosquito Ghaut. Access to the exclusion zone is completely restricted, and people should stay away from the flanks of the volcano. People should remain vigilant and continue to listen to Radio Montserrat.