Earthquake swarm in Krýsuvík volcano

Since last night (night of 3-May-2021) there has been earthquake swarm in Krýsuvík volcano close to Kleifarvatn lake. At the writing of this article this earthquake swarm is ongoing.

Earthquake swarm in Krýsuvík volcano shown by two green stars on top of each other
Earthquake swarm in Krýsuvík volcano. Copyright of this image belongs to Icelandic Met Office.

Largest earthquakes in this swarm had a magnitude of Mw3,2 and there where several other smaller earthquakes that also happened. The earthquake at 03:04 UTC was felt in Reykjavík but I don’t have any reports about the earthquake at 15:49 UTC with same magnitude being felt. It is difficult to know what this earthquake activity means but for now the idea is that this earthquake activity might be connected to stress changes because of the magma dyke connected to the eruption in Fagradalsfjall mountain that is happening within same volcano system.


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I am taking a little vacation between 5 May and until 10 May. Unless something major happens next update won’t be until after 10 May 2021. I am hoping to see the eruption or the area if the eruption is not ongoing next weekend if weather allows for such a trip. I don’t know yet if I can see the eruption, but I hope that I am going to have a chance to see the eruption.

7 Replies to “Earthquake swarm in Krýsuvík volcano”

  1. Vacation time starts today. If I can get to the eruption I’ll be posting videos and pictures soon as I can if the mobile connection is poor at location of the eruption. Next update is going to be after 10 May unless something major happens and then I’ll post update soon as possible.

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  2. Jón, hopefully you had a very good trip, from your posts on Facebook it looks like you did. Do you have any thoughts on this unusual/unknown situation with the volume of magma output being at its greatest after 8 weeks? The experts were talking about this yesterday, but they didn’t feel able to give an opinion as to what it might mean.

  3. My on view is that this might be a start of a new main stratovolcano. This progress of how a volcano starts has never been observed before, I think. It seems that the magma is slowly creating a magma chamber below the only crater that is eruption. Both shallow and deep magma chambers. This is going to take few months to years?

    I can’t say that my idea has gained any support so far. But I don’t think the eruption is going to end any time soon and the area is going to change a lot in next few weeks as more lava piles up in Fagradalsfjall mountain (soon to be remained Fagradalsfjall volcano?).

  4. Based on your recent experience, can you give an estimate of the height of the crater walls? It is hard to guess from the webcam views. And, thank you for all this information, I always look forward to your posts.

  5. The crater is large. It is 50 to 70 meters above the ground floor in the area. Collapses are always changing the height of the crater. It is also wide, about 30 to 60 meter wide, but that number is also always changing because of collapses.

    1. It seems that the rhythm of the lavajets is about the same as the rhythm of Geysir/Strokkur (every 5 to 10 minutes).
      Is this a coincidence or might there be an underground connection between the systems?

    2. It seems that the rhythm of the lavajet is about the same as the rhythm as the of geysir-strokkur. About every 5 to 10 minutes. Is that a concidence or is there an explanation for. There might be a connection in the deep earth.

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