Report for the period midday 20 April to
27 April 2007 Visual observations revealed very little change to the overall
dome structure during the period, although fresh deposits can be are present
in the head of Tyres Ghaut and in the upper part of the Tar River. As the
dome stands, a significant proportion of the dome material remains in the
sector above Tyres Ghaut to the northwest. The amount of material here
is sufficient to generate pyroclastic flows and surges capable of impacting
on the lower Belham Valley.
Recorded seismic activity has remained
very low throughout the period. The seismic network recorded just 3 rockfall
signals and 1 long-period earthquake.
The sulphur dioxide (SO2) flux rate during
the reporting period was variable, ranging between a minimum of 174 tones
per day (t/d) to a maximum of 754 t/d. The average of 476 t/d is in line
with the long-term average for the eruption.
level remained at 4.