Over the last 24 hours activity at the volcano has continued to be dominated by rockfalls and pyroclastic flows. The main activity has been in Mosquito Ghaut with a small pyroclastic flow observed there at 11.10 this morning. However, a helicopter flight showed that there are new spines growing above the Gages valley and some rockfalls were observed into the top of Fort Ghaut. Over the reporting period 26 hybrid earthquakes, 4 VT earthquakes, 38 long-period earthquakes and 143 rockfalls triggered the broadband seismic network.
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 it should be remembered that ash and falling rocks make driving hazardous. After ash has fallen it will remain present in the atmosphere for some time and dust masks should be worn outdoors.
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.