For this update, our information comes from IMO and the Department for Civil Defence. We will update our earthquake plots later on.
The eruption which started yesterday on a ridge in Geldingadalur has been assessed as a minor one, contained in the valley; the eruptive fissure is around 500m to 700m long; and, there is no ash or tephra. Levels of S02 are low, except near the eruption site; gases can accumulate in the valley or other depressions. The main road to Keflavík from Reykjavík has been opened. However, the road between Grindavík and Þorlákshöfn is closed. The aviation code has been lowered to orange.
The eruption may change without notice. The Department of Civil Defence warn of the potential for new fissures opening either at the current site or elsewhere from the dyke near Fagradalsfjall. Large earthquakes are considered unlikely at the eruption site but the risk for a magnitude 6.5 still remains for Brennisteinfjöll. At the moment seismicity on the Reykjanes Peninsula is much reduced.
Hazards for those visiting the site are getting too close to the lava flow and not being able to outrun any lava that breaks off it; the craters are unstable and may break, releasing a lava flow; and explosions where hot lava meets water-logged ground. The Department of Civil Defence advises observers to keep to the hills surrounding the site. Not that it is easy to get to without a helicopter!
Local webcams have been set up from which the rest of us can watch; one is:
For up-to-date advice, please consult IMO or the Department for Civil Defence.
The Armchair Volcanologist
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Department for Civil Defence: https://www.almannavarnir.is/