The crustal uplift at Svartsengi is slowing down, according to a new notice from the Icelandic Meteorological Office. This is an indication that magma pressure is building and that a new magma intrusion or volcanic eruption are becoming more likely.
These developments, confirmed by GPS data discussed by a group of Met Office scientists, are similar to the ones observed on December 15, three days before the eruption at Sundhnúkagígar began. “It’s difficult to assert that this pattern will repeat,” the notice adds.
Seismic activity stable
The first sign of a magma intrusion is a sudden increase in seismic activity, much like before the December 18 eruption that lasted only a few days. Seismic activity has been stable in recent days, however, with around 200 earthquakes per day. Most of the quakes are measured at under 1.0 on the Richter scale. 30 have been above 1.0 since December 29, with the largest one at 2.1 on the north side of the town of Grindavík. The town was evacuated on November 10, but residents were allowed to return to their homes after the eruption just days before Christmas.
Sundhnúkagígar the most likely eruption spot
The Met Office scientists estimate that if an eruption takes place it will be at Sundhnúkagígar again, in between Stóra-Skógfell and Hagafell. Magma intrusions do not always result in a volcanic eruption and this has been observed in previous developments in the Reykjanes peninsula.