Volcano and earthquake activity in Iceland
On 18-August 2025 at 18:10 UTC an earthquake with magnitude of Mw3,8 took place in Brennisteinsfjöll volcano. This earthquake was felt in Reykjavík and nearby towns.
This earthquake swarm has stopped. There is a lot of stress on the crust in this part of Reykjanes because of the ongoing inflation and deflation cycle in Svartsengi volcano. Larger earthquake might happen without warning.
On the 27-July 2025 at 23:39 UTC an earthquake with magnitude of Mw5,2 took place in Bárðarbunga volcano. A second earthquake with magnitude of Mw3,1 took place at 23:41 UTC. That second earthquake is embedded into the first earthquake and that makes it impossible to see it in earthquake data without good analyse. The largest earthquake was felt in Akureyri, far north of Bárðarbunga volcano.
This is normal earthquake activity as Bárðarbunga volcano continues to inflate. This large earthquake happen every few month in Bárðarbunga volcano.
During the night of 20-July 2025 at 02:55 UTC an earthquake with magnitude of Mw3,5 took place in Krýsuvík volcano. This earthquake was felt in Reykjavík and other nearby area.
This is a tectonic earthquake. Possibly adjustment in the crust the eruption that is happening in Svartsengi volcano. Since the eruption results in the Svartsengi volcano to deflate. This earthquake swarm seems to be over for now.
This is a summary update with best information I have at the moment. Some information might be out of date without me knowing about it.
If there is anything more to report. I’ll post update here about it. I don’t expect there is going to be any need for any future update at the writing of this article.
Updated at 00:59 UTC on 17th of July with missing information.
Today (16-July 2025) at 03:53:31 UTC an eruption started in Svartsengi volcano in Sundhnúkagígaröðinni crater row. This is the most northern part of the eruption area. Far from anything important. The eruption fissure doesn’t look large based on what can be seen on web cameras.
It is impossible to know how long this eruption is going to last. It might be few hours and up to few days. If needed. I’ll post updates about the eruption. Normally in this type of eruption that is not required.
Yesterday (18-June 2025) a small earthquake swarm started in Krýsuvík volcano. The largest earthquake had a magnitude of Mw3,4 and was felt in Reykjavík and nearby area.
This earthquake swarm is possibly because of the inflation in Svartsengi volcano. More earthquake activity might happen in this area because of that inflation in next few weeks.
Yesterday (16-June 2025) at 18:05 UTC an earthquake with magnitude of Mw3,7 took place in Ljósufjöll volcano system at the depth of 18 km. It was felt in nearby area that does not have any dense population.
This earthquake activity continues to happen because of magma inflow into the crust at this location. Since the inflow of magma started at this location, the magma has not moved up into the crust that can be noticed. Resulting in pressure building up at the lower end of the crust in this part of Iceland. The crust in this area is not giving into the pressure from the magma easily and this crust is also old, dense and brittle. Making it much more difficult for any magma to move to the surface.
Deep earthquake activity continues in Eyjafjallajökull volcano. In recent weeks however the earthquake activity has been getting shallower. Going from 29 km depth and up to 24 km depth.
This activity is far away from any eruption happening again in Eyjafjallajökull volcano. This however is an interesting development. Since this is happening only 15 years after the eruption in Eyjafjallajökull volcano.
During the night of 26-May 2025 at 02:31 UTC an earthquake with magnitude of Mw3,3 took place in Hrómundartindi volcano. This earthquake was felt in Hveragerði town. Few smaller earthquakes followed the largest earthquake.
Earthquake activity happens in this area regularly and there is nothing suggesting that his earthquake activity is because of magma movement in the area.
Today (24. May 2025) there has been a strong earthquake swarm. Largest earthquake in this swarm so far had a magnitude of Mw5,1. It was felt over a wide area in south Iceland. Over 40 earthquakes with magnitude Mw3,0 or larger have taken place in last few hours.
At the writing of this article. The earthquake swarm is ongoing but seems to be slowing down at the writing of this article. Earthquake activity in this area can increase again suddenly. Icelandic Met Office says this earthquake swarm is because of tectonic movement. In my personal view there is a chance magma might be the reason for this earthquake swarm. The exact reason for this earthquake swarm is unclear at the writing of this article. That might change if this earthquake activity increases again.