14.03.2021: The magma intrusion on the Reykjanes Peninsula appears to be edging further southward. The longer this continues, the more likely an eruption.  New plots added (Figs 13 – 15).

Update 14.03.2021

We have moved updates to the beginning of this post. The original post from 9 March 2021 and the earlier update are below.

We have updated our plots to 14.03.2021 17:46 for the area between 63.83314°N, 22.55148°W to 63.96605°N, 21.8566°W .  Here are the results; the magma intrusion appears to be edging slowly further southwards, if we use the Department of Civil Protection’s line that the earthquake locations are the best indicator at the moment of where the magma is.

For the current status and advice, please consult IMO.

The Armchair Volcanologist

Update 12.03.2021

Since we wrote [our original post], the earthquake swarm continues unabated with several thousand more earthquakes and some more tremor pulses.

The Department of Civil Protection report today includes the following:

“Earthquake activity now reaches up to the Nátthagi valley south of Fagradalsfjall, which suggests that the southernmost end of the magma path lies there.  

The magma path continues to expand although there is some uncertainty regarding the pace of the magma flow. Data has indicated that the magma path has been moving towards the south coast in the last few days, but latest surveys do not indicate that the path has moved notably in the last 24 hours. 

With view of the eruption history and geological research, a volcanic fissure opening south of Fagradalsfjall and reaching the ocean is unlikely. Given the current circumstances, an undersea eruption with associated ash eruption is therefore unlikely.     

As has been stated earlier in the Science Board’s notifications, while the magma path continues to expand it must be assumed that an eruption may occur in the area. The longer the current situation lasts, the more likely an eruption becomes. “

They also note that gas measurements are being taken in the area.

Our updated plots show the seismic activity moving further southward, notably the geodensity plot in Fig 12.  There is also some parallel activity further west on a much smaller scale.

For the current status and advice, please consult IMO.

The Armchair Volcanologist

09.03.2021

An eruption considered likely; magma c. 1km below the surface.

Good Afternoon!

Despite the earlier tremor pulses, the Krýsuvík Volcanic System has not yet erupted.  However, as seismicity continues to be intense, with well over 34,000 earthquakes recorded by Iceland’s SIL system now since 24 February 2021, it is thought that an eruption is likely. 

The latest report from Iceland’s Civil Protection Service Council on March 8, 2021, states that if an eruption occurs, the most likely scenario is still a fissure eruption between Fagradalsfjall and Keilir.  A magma intrusion (they use the term tunnel) is forming in the region, with most recent activity at its southern end.  Magma has now reached an upper depth of c. 1 km.  GPS and satellite readings indicate that the magma flow has decreased in the past week.  If the intrusion continues to grow, further surges in seismic activity can be expected.

The earthquakes trending westward from the vicinity of the magma intrusion are thought to be the result of the crust accommodating the intrusion.  No other magma movement has been detected during this swarm. 

So where are Fagradalsfjall and Keilir?  Here is a map (with directions on how to drive from one to the other, not that we would recommend that at the moment).

We have plotted the confirmed earthquakes for week 8 and week 9 2021, plus a few hours of yesterday, between 63.7°N, 21.0°W to 64.4°N, 23.0°W download from IMO’s site.  Here are the latest plots for the Reykjanes Peninsula, 63.7°N, 21.0°W to 64.4°N, 23.0°W:

If we zoom in on the area between 63.83314°N, 22.55148°W to 63.96605°N, 21.8566°W we can take a closer look at the intrusion, itself, (or the earthquakes magma movement is causing).  The area was selected to take in Svartsengi, Fagradalsfjall, Keilir and Krýsuvík.

Since we downloaded the data for the above plots, IMO have reported another short-lived burst in seismic activity at 05:20 this morning with a seismic tremor Mt. Fagradalsfjall, south of the intrusion.

IMO have produced a map of the dike intrusion and the areas of seismic activity that are arising due to the increased tension in the crust caused by the intrusion.

For the current status and advice, please consult IMO.

The Armchair Volcanologist

© Copyright remains with the author; all rights reserved, 2021.

Sources:

Icelandic Meteorological Office (IMO): https://en.vedur.is/

Map in Fig 8: https://en.vedur.is/about-imo/news/earthquake-swarm-in-reykjanes-peninsula

Department of Civil Protection: Vísbendingar að kvikugangurinn liggi suður af Fagradalsfjalli  (Scroll down the page for the English version).