Daily update on Krýsuvík volcano activity on 2-March-2021 at 20:07 UTC

This is a short update on the activity in Krýsuvík volcano. The activity has been confirmed to be only in Krýsuvík volcano and nothing is currently happening in Reykjanes volcano at the writing of this article.

Krýsuvík volcano started to show changes in late 2008 and early 2009 and that has been going on since then in low activity. Krýsuvík volcano is strange in that it does not have any shallow magma chamber in the top layers of the crust and Krýsuvík volcano size is unclear. This uncertainty shows in maps as different maps show different size and location of Krýsuvík volcano. While there is no shallow magma chamber in Krýsuvík volcano it does not rule out a deep, large magma chamber that does not show up on any seismometer since this magma chamber is located in the top layers of the mantle (10 to 30 km).

Green stars show the location of the earthquake activity in Krýsuvík volcano on Reykjanes peninsula. They are located on a small narrow band in almost south-west and north-east location and there is one cluster of earthquakes close to Trölladyngja tuff mountain
Earthquake activity in Krýsuvík volcano. Copyright of this image belongs to Icelandic Met Office.

Largest earthquakes since midnight had a magnitude of Mw4,6 and since around 12:00 it has been rather quiet in Krýsuvík volcano when it comes to large earthquakes. A lot of smaller earthquakes have been taking during all this time and there is no sign of those stopping. The reason for all this earthquake activity is a magma dyke that is now breaking its path up to the surface from around 10 km depth. There are nothing to suggest that process is about to stop or slow down. Drop in activity as is now happening are common feature of this type of dyke activity and was seen just before the eruption in Bárðarbunga volcano (Holuhraun) in 2014 to 2015.

Earth Science department of University of Iceland released a pictures that show how this dyke in Krýsuvík volcano works and that image can be viewed here on Facebook.

If anything major happens I am going to post an update soon as possible. Next update is tomorrow (03-March-2021) if activity remains as it currently is.

Article updated at 20:25 UTC. Fixes in the text.

Minor earthquake swarm north-east of Grímsey island

Yesterday (01-March-2021) at 19:53 UTC an magnitude Mw3,3 earthquake took place north-east of Grímsey island. This might be a new earthquake swarm in this area since earthquake swarms in Tjörnes Fracture Zone often star slowly. Earthquake swarms are common in this part of Iceland.

Green star and yellow and red dots north-east of Grímsey island
Earthquake activity north-east of Grímsey island. Copyright of this image belongs to Icelandic Met Office.

There is a chance of a stronger earthquake swarm in this area. Currently the activity remains small and nothing more might happen. This earthquake activity is not connected to what is happening on the Reykjanes peninsula.

Next article about Reykjanes peninsula activity is going to be written tomorrow (2-Mars-2021) unless something major happens.