The level of seismic activity at the volcano remains low, but there is evidence of increasing instability of the north-east face of the dome. There has been an increase in rockfall activity from the dome, and a few small pyroclastic flows.
The seismic activity today was very low with only one volcano-tectonic and one hybrid earthquake. However, the level of rockfall activity recorded by the network has increased for the second day in succession, with 49 rockfall signals recorded. Some of these signals were associated with pyroclastic flows that produced small ash clouds.
Good views of the crater area were possible today, and the north-east face of the dome is becoming increasingly unstable. Some rockfalls and some ash venting were seen from this face. There were also rockfalls to the south-east, from the active face of the January 20 dome, and a large unstable block was seen at the top of this face.
COSPEC measurements were made this morning and the results will be available tomorrow. Yesterday's readings gave an average of 159 tonnes per day of sulphur dioxide emission, which continues the recent trend of low values.
GPS measurements were made today on the lines to the east of the volcano.
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.