Report for the period 4 pm 28 August
to 4 pm 29 August 1997
Activity at the volcano has continued at a slightly reduced level
compared to yesterday. There were small pyroclastic flows down Tar
River Valley at 7:55 this morning, and down Mosquito Ghaut at 4:02 this
afternoon.
Visibility was excellent for much of the day and further work was carried out to survey the dome using photographs and GPS. Over the last 24 hours 1 hybrid earthquake, 9 VT earthquakes and 66 rockfalls triggered the broadband seismic network. Of 23 long period earthquakes 13 were associated with rockfall signals.
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. Material accumulating behind St. George's Hill may now make it possible for pyroclastic flows to travel into the Belham river valley from the Gages Valley as well as 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.