Seismic activity continued to be strong in October. The eruption continued apace, subsidence of the caldera continued at about 40 cm per day and the earthquakes continued with regular M5 tremors around the caldera rim and smaller tremors at the eruption site. Larger volumes of sulphur dioxide were emitted. A crater named Baugur and a new lava flow to the east formed at the eruption site in Holuhraun. Geothermal heat was on the increase and the depression in the caldera was 40 metres, subsidence continued at a similar rate to previous weeks. A cauldron in the south-east corner of Bárðarbunga deepened 25 metres in one month and was considered by scientists at the site to be linked to the depression in the caldera. Seismic activity continued in the dyke although at a reduced rate. GPS measurements around the area of activity showed minor changes. Air quality continued to be affected by the eruption.