Seismicity during the reporting period has been dominated by a swarm of small, low energy long-period earthquakes which started around midday (local time) Sunday 16 July and ended by the morning of Wednesday 19 July. This was slightly preceded by an increase in rockfall activity, although this could equally well be due to heavy rainfall at the end of the previous reporting period, than indicative of deeper processes. The seismic network recorded 9 hybrid earthquakes, 293 rockfall signals, 46 long period rockfall signals and 341 long period earthquakes during the reporting period. Seismic activity had decreased and was dominated by small rockfall signals by Friday 21 July.
Sulphur dioxide flux measures over the reporting period were variable, the lowest value measured was 262 tonnes/day on the 18th of July and the highest 697 tonnes/day the following day, with an average of 523 tonnes/day. This value is close to the long term average of 500 tonnes/day. The FTIR is still abroad being repaired.
The GPS network data is now available to 06 July and shows a shortening of the lines between receivers. This is interpreted as contraction of the volcano's flanks or emptying of the magma chamber.
The alert level is currently 3.