Montserrat Volcano Observatory

Daily Report
Report for the period 4 pm 13 June
to 4 pm 14 June 1997
The current alert level is ORANGE

Pyroclastic flows continue to occur in regular pulses with most of the flows travelling down the Tar River valley.

The level of pyroclastic flow and rockfall activity reached a peak at about 2am but had subsided by 9am this morning. Several small pyroclastic flows were observed in the Tar River valley and one small flow was observed in the upper parts of Tuitt's Ghaut this morning. There was rockfall on the northern, north-eastern and eastern flanks of the volcano. The volcano has been relatively quiet throughout the afternoon with occasional small pyroclastic flows and rockfalls.

Observations from Windy Hill and from a helicopter flight this afternoon indicate that a considerable amount of rockfall debris has accumulated in the upper few hundred metres of Mosquito Ghaut since observations were last made a few days ago. The top of Mosquito Ghaut has been widened slightly by rockfall activity. Although visiblity was poor for most of the day, the dome was briefly revealed this morning. The northern flanks are reported to be extremely steep and the summit area is rather flat in appearance.

There were only two significant long period earthquakes today, a substantial decrease from the 27 recorded yesterday. The number of rockfalls has also decreased today to 82. There has been a slight increase in the number of hybrid earthquakes to 16, of these, 7 triggered rockfalls.

Two COSPEC runs were made today to measure the amount of sulphur dioxide being expelled from the volcano, the results will be reported tomorrow.

Further pyroclastic flow and rockfall activity is expected, and could easily extend down Tuitt's Ghaut or Mosquito Ghaut. Although pyroclastic flows have been relatively small over the last few days, larger pyroclastic flows could occur with no warning. Pyroclastic flows and surges are hot and travel extremely fast, they cannot be outrun. Zones A and B on the risk map should not be visited. WH Bramble airport remains operational for the time being, although the public are reminded it is open for essential travel purposes only: people not travelling should not visit the airport.

Montserrat Volcano Observatory