Volcano and earthquake activity in Iceland
Today (5-July 2024) an earthquake swarm started in Brennisteinsfjöll volcano. Largest earthquake had a magnitude of Mw3,1 at 07:17 UTC. This earthquake was felt in Reykjavík and nearby areas.
At the writing of this article, the earthquake swarm seems to have stopped. It might restart again, since that is common in this volcano and in this area.
Yesterday (26-June 2024) at 17:07 UTC an earthquake with magnitude of Mw3,1 took place in Brennisteinsfjöll volcano, not far from Bláfjallaskáli area. That is a popular skiing area during the winter.
This earthquake was part of a small earthquake swarm in the same area. It seems to have quieted down again.
Yesterday (23-June 2024) at 22:42 UTC an earthquake with magnitude of Mw3,1 took place in Brennisteinsfjöll volcano.
There are no reports of this earthquake being felt. Aftershocks are a possibility in this part of Brennisteinsfjöll volcano.
Yesterday (26. January 2024) and today (27. January 2024) an earthquake activity took place in Brennisteinsfjöll volcano, in the Bláfjöll area. The first earthquake had a magnitude of Mw2,4 at 22:54 UTC on 26. January 2024 and the second earthquake had a magnitude of Mw3,1 on 27. January 2024 at 05:28 UTC. Smaller earthquakes started later today. That earthquake activity seems to have ended at the writing of this article.
This earthquake activity, at least in the case of the Mw2,4 and Mw3,1 earthquake did show a sign that they where created by magma movement, among those signs was a strong vertical movement and low period signal that only happens when magma creates earthquake. At this point in time, I don’t think an eruption is going to happen any time soon. It is possible that magma has started to collect in Brennisteinsfjöll volcano. It is going to be several years until something more happens, it might even take decades before anything serious happens.
I am sorry that I am late on writing this article. I was moving from Denmark to Iceland and that was a lot of effort and I’ve been tired after this move.
On Sunday, 24 September 2023 an earthquake swarm took place in Brennisteinfjöll volcano, in a area called Geitarfell (Goat Mountain) in Brennisteinsfjöll volcano. Largest earthquakes had a magnitude of Mw3,0 to Mw3,2. A lot of smaller earthquakes took place at this same location.
This earthquake activity didn’t have any short term signs that an eruption is about to happen at this location. I don’t know when last eruption took in this location, but it was clearly more than 6000 years ago.
Earthquake webicoders
Since I have moved back to Iceland. I am now recording earthquakes again. The webicoders are going to go online tomorrow (if no delays). They can be found here once they are back online.
During the night of 26. August 2023 an dyke intrusion started in Brennisteinsfjöll volcano. This was in the form of many small earthquakes, most of them did not reach magnitude Mw1,0. What gives this away as an dyke intrusion is the fact the deepest earthquake in this swarm had a depth of 21,1 km. There was interestingly, a lot of surface earthquakes. I am not sure on why that is.
There’s no risk of eruption at the moment from Brennisteinsfjöll volcano. Earthquake activity is too low and this process is clearly not far along now for an eruption too happen. That might change without much warning at some point.
Today (13. April 2023) there has been a small earthquake swarm in south part of Brennisteinfjöll volcano. This location had an earthquake swarm few weeks ago at this same location. It also was small in magnitude. Depth of this earthquake swarm has now decreased from 7 km to around 3 km. At least that is what it seems, based on the current earthquake data.
This earthquake activity shows a sign of magma movement. It is my opinion that the magma is now pushing it self trough the crust at this location. That can take a while, up to several weeks before an eruption starts. I did see something similar happen before the Bárðarbunga volcano eruption in 2014. That process took good three months before the eruption and was marked by small earthquake swarm like this one. How long this is going to take is impossible to know, because what type of crust is at this location is not well understood (outside of types of rock it is made out of at the first top layers). This is in my view an earthquake activity that needs to be monitored, because of possible eruption risk at this location. This is directly north of a small lake south of the earthquake swarm. If an eruption happens and the lava flows into the lake, that might create a lot of problems.
This earthquake swarm can be viewed here in more details. The website is Skjálfta-Lísa and is only in Icelandic.
Earlier this week, an swarm of earthquakes started in south of Brennisteinsfjöll volcano, also known as Bláfjöll mountain. This earthquake swarm started on a west to east fault north of a lake called Hlíðarvatn. This earthquake swarm has only been minor earthquakes, with magnitudes in the range of Mw0,0 and up to Mw2,3 but at the writing of this article, nothing above that magnitude. Over the week this earthquake swarm has evolved into a single area that seems to be circular, based on current earthquake activity. This strongly suggests that magma is the reason why this earthquake swarm is happening.
At the writing of this article, the earthquake activity is too small to start an eruption. Since this area is cold and the crust is too hard for the magma to flow freely inside it. Current depth of the earthquakes is around 5 to 7 km at the writing of this article and has not changed a lot during the week. While the Skjálfta Lísa image does not show this, it is possible that the earthquake activity has started to spread more east, compared to earlier in the week when this activity started. This earthquake actiivty might stop, as often happens in the early stages of a new eruption cycle in a volcano.
Early morning of 7. January 2023 an earthquake swarm took place in Brennisteinsfjöll volcano. All of the earthquakes are small in magnitude and largest earthquake had a automatic magnitude of Mw1,0. Depth of this earthquakes is from 7 km and down to 9,5 km depth.
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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.
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.