Montserrat Volcano Observatory

Daily Report
Report for the period 4 pm 8 October
to 4 pm 9 October 1997

There have been two further explosions in the last 24 hours bringing the total number of explosive events since 22nd September to 44. There was no warning or precursory seismic activity to either event.

This morning's explosion took place at 3:03am, almost 12 hours after the previous eruption. The ash column from this event rapidly reached a height of at least 10,000ft and drifted slowly to the north west. Pyroclastic flows generated during this explosion were observed to travel down Tuitt's Ghaut, Farrell's plain and Gages Valley. The explosion was followed by a period of tremor caused by vigorous ash and steam venting.

The second explosion occurred at 12:32 this afternoon and a vigorously convecting ash column rose to at least 20,000ft. About 20 or 30 seconds after the first blast there was a second audible explosion and a visible pulse in the activity. Pyroclastic flows were observed to travel down Tyer's Ghaut, Tuitt's Ghaut, Mosquito Ghaut and Gages Valley. The lower part of the ash cloud moved to the west over Plymouth and the upper part of the ash cloud moved to the north west. There was no ash fall on inhabited areas. Ash venting was vigorous and was sustained for at least 30 minutes before the venting developed a pulsing nature.

The seismic activity has remained low with only 4 long period earthquakes, 6 hybrid earthquakes and 6 rockfalls triggering the short period seismic network.

Work began today clearing a new observation site in the Centre Hills. This site provides clear views of the summit crater of the volcano and of the south eastern round to the north western flanks of the volcano.

More explosions are expected, these may be larger than those already experienced and may send pyroclastic flows and surges further down Tyer's Ghaut and into the Belham River. Explosive eruptions may occur with no warning, therefore all residents still remaining in Friths, Old Towne and Salem are urged to move out as soon as possible.

After explosions, fallout can occur anywhere on the island and hard hats or other suitable protection should be worn outside. The ash deposited over the last few days continues to make roads dangerous and although there is less ash today than over previous days, the wearing of ash masks is still recommended at all times. Everyone is advised to keep listening to Radio Montserrat for information on the activity.

Montserrat Volcano Observatory