Seismic activity at the volcano has been low during the period although the dome continues to grow and there is evidence of increasing instability of the north-east face. Rockfall activity generated small ash clouds throughout most of the day.
The seismic activity today was very low with only three long-period events and one hybrid earthquake. No volcano-tectonic earthquakes were recorded during the past 24 hours. Seismic activity has again been dominated by rockfall signals, with 35 rockfall events recorded. Some of these signals were associated with pyroclastic flows that produced small ash clouds which drifted towards the west with the prevailing winds.
A late evening flight yesterday showed strong incandescence on the January 20 dome and down a new chute in the October 1 dome. Faint incandescence was also observed over the entire north east face of the October dome. Good views of the crater area obtained today indicate that this area of the dome has developed further rockfall chutes and is now crumbling widely. Rockfalls and small pyroclastic flows continue to build up the scree slope at the base of the dome in the south-east and north-east.
The observations of increased instability of the north-east of the dome, and an increase in rockfalls indicate that the volcano is active and potentially dangerous. Given that the dome is now large and continuing to grow, a large collapse and pyroclastic flows could happen with little warning. It is dangerous to spend the night in evacuated areas, because the situation could worsen dramatically over a period of a few hours. People entering Zone C are reminded to remain alert at all times, and spend the minimum possible time in the evacuated zone. The Tar River Valley and the upper Galway's area are very dangerous and should not be entered at any time.