Earthquake swarm in Krýsuvík-Trölladyngja volcano

Today (21. December 2022) an earthquake with magnitude of Mw3,4 took place in Krýsuvík-Trölladyngja volcano. This earthquake is because of inflation in Fagradalsfjall volcano. This possibly means that the inflation in Fagradalsfjall volcano is reaching critical point and might result in a eruption soon, when that point is reached is difficult to know.
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Earthquake swarm 3 km north of Grindavík town

Today (19. December 2022) and yesterday (18. December 2022) an earthquake swarm took place 3 km north of Grindavík town in the Reykjanes volcano. Largest earthquake had a magnitude of Mw2,9 and was felt in Grindavík. Earthquakes with magnitude Mw2,0 are felt in Grindavík, possibly even smaller earthquakes. At the writing of this article, this earthquake swarm is ongoing but weather is blocking almost all of the automatic earthquake detection.
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Earthquake swarm in Reykjanes volcano (3-December-2022)

Today (03-December-2022) at 12:49 UTC an earthquake with magnitude of Mw3,5 at 7,0 km depth. This was the largest earthquake in the swarm. Around of 40 earthquakes took place at the writing of this article. There are no reports about the largest earthquake was felt in nearby populated areas.

Green star on the left down corner of the image with orange dots showing smaller earthquakes. With few red dots in the same area.
Earthquake activity in the Reykjanes peninsula. Copyright of this image belongs to Icelandic Met Office.

This earthquake activity suggest that a new inflation period is about to start in this part of the Reykjanes peninsula and Reykjanes ridge. There has been rather quiet time in Fagradalsfjall volcano and Reykjanes volcano since August when last eruption took place in Fagradalsfjall volcano. Reykjanes volcano has not erupted so far, but has continued activity of magma injection into the crust. When that is going to result in a eruption is impossible to know.

Possible dyke intrusion in Fagradalsfjall volcano

Early morning today (10-November-2022) an swarm of earthquakes took place slightly north of the place where the eruption in August 2022 took place in Fagradalsfjall volcano. This possible dyke intrusion was small and only lasted for about 1 hour before it stopped. Depth of the earthquakes was from 5 km to 7 km.

High resolution image of the earthquakes in Skjálfta-Lísa interactive earthquake map from Icelandic Met Office. It shows the dots line up in a fissure like location.
Skjálfta-lísa high resolution map of the earthquake activity. From Icelandic Met Office website.

This activity might give a clue on in what area next eruption is going to take place in Fagradalsfjall mountain. Based on earlier eruption there won’t be any warning before an eruption earthquake swarm starts. In August that eruption started with a minor earthquake swarm, created from a dyke intrusion that was happening. In the hours before an eruption starts there’s going to be a strong earthquake swarm, based on what happened just before the eruption in August. It is interesting if the eruption activity moves north-east, rather than south-west. Why that happens, if it does so, is not something I am clear on why happens.

Earthquake swarm in west part of Fagradalsfjall volcano

This morning on 23-October-2022 an earthquake swarm took place in west part of Fagradalsfjall volcano. Largest earthquake in this swarm so far had a magnitude of Mw3,0.

Green star just west of main Fagradalsfjall volcano. Few blue, yellow and red dots on the map showing earthquakes in other nearby volcanoes
Earthquake activity west of Fagradalsfjall volcano. Picture from Icelandic Met Office.

This earthquake activity is the result of magma pushing up into the crust at around 5 km depth. This is not a large dyke intrusion and possibly won’t result in a eruption, unless there’s a sharp increase in earthquake activity and that has happened (the August 2022 eruption started this way). This is currently a situation that requires monitoring for changes. If anything is going to happen is impossible to know.

Earthquake swarm in Brennisteinsfjöll volcano

Today (21-October-2022) an earthquake swarm took place in Brennisteinsfjöll volcano. Largest earthquake had a magnitude of Mw3,0 at 10:23 UTC. This earthquake swarm is possibly over, it is however difficult to be sure.

Red dots in Brennisteinsfjöll volcano on Reykjanes peninsula, located just south of Reykjavík city and east of Kleifarvatn lake. A lot of yellow and orange dots on the map in few volcanoes showing smaller earthquake activity
Earthquake activity in Brennisteinsfjöll volcano and other nearby volcanoes. Picture is from Icelandic Met Office.

This is probably just a tectonic earthquake activity. But it is worth noting that volcano activity as has been seen in Fagradalsfjall volcano (Iceland newest volcano) is going to move east on Reykjanes peninsula. How fast and how long that change is going to happen is not known because of lack of data and written records from 700 to 900 years ago are incomplete and vague on details at best.