Lava extrusion has continued throughout the reporting period. A new lobe has developed growing from the summit area towards the south, shedding rockfalls in a sector from the west around to the southeast sides of the lava dome. The steep back of this shear lobe is visible from the Salem area. The dome currently has a volume of approximately 80 million cubic metres and the average growth rate through April was about 8 cubic metres per second.
During the reporting period, seismicity was dominated by rockfall activity, as has been the case throughout this phase of dome growth. The seismic network recorded 571 rockfall signals, 96 long period-rockfall signals and 74 long period earthquakes.
Measurements of the sulphur dioxide flux were taken on five days during the reporting period and ranged from 395 tonnes per day (t/d) on 06 May to a peak of 1343 t/d on 07 May. The average for the period was 702 t/d.