Large earthquake swarm in Krísuvík volcano

After four days of continues earthquake activity it appears that Krísuvík volcano has stepped up it’s activity by a order of magnitude. Since midnight there have been over 400 earthquakes in Krísuvík volcano. The activity is continuing when this is written and does not show any signs of slowing down at this moment. Geologist in Iceland are expecting more earthquakes in this area over the next hours and even earthquakes that are larger then ML3.0 in size.

The largest earthquakes where ML3.3 and ML3.7 in size. This is automatic size by the SIL system. The depth of the earthquakes was 4.7 km and 1.1 km according to the automatic SIL system. Due to high number of earthquakes the SIL system is putting earthquakes down all around the Reykjanes Peninsula. While there might be some earthquakes there, the number is not nearly as high as can be seen on the map. The earthquakes can be located by there low quality number.

Given the location and how this earthquake swarm is behaving it is my opinion that this is due to a magma is pushing up the crust in this area. But it remains a question of this is going to start a eruption or not. But the chances are growing for as long as this earthquake pattern holds up in Krísuvík volcano. If a eruption starts in Krísuvík volcano it is going to one of Hawaii type eruption, unless it is under water then it is going to be explosive for as long there is water getting into the crater. Last time there was a eruption in this area a 25 km long eruption fissure did form.

For now however all that can be done is to wait and see what happens. This earthquake swarm is going to continue for the next few hours and even days. The largest earthquakes can be seen on my geophone sensors here.

Map of the earthquake swarm in Krísuvík at 15:00 UTC. Picture is from Icelandic Met Office web page. Copyright belongs to them.

Icelandic news about this earthquake. Use Google translate at own risk.

Búist við áframhaldandi virkni (Rú
Engin merki um gosóróa (Rú
Heldur rólegra síðasta hálftímann (Ví
Jarðskjálftinn var 4 stig að stærð – 200 skjálftar frá miðnætti (Ví
Jarðskjálfti í Reykjavík (Ví, 09:13 UTC)
Hætta á fleiri skjálftum (
Skjálftinn var nær höfuðborgarsvæðinu (, 11:00 UTC)
Jarðskjálfti í Reykjavík (, 09:07 UTC)
Skjálftinn líklega 4 stig (
Kort af skjálftanum (
Dregið hefur úr skjálftahrinunni (Ví
Tveir snarpir jarðskjálftar 24 km SSV af Reykjavík (

Note: Check time stamps of the news articles.

Blog post updated at 14:50 CET on the 27.02.2011.

Blog post updated at 16:14 CET on the 27.02.2011.

144 Replies to “Large earthquake swarm in Krísuvík volcano”

  1. Well, then, no fireworks. 🙁
    But I must say I’m happy that nothing really serious develops here. Not so close to inhabited areas.

    1. Maybe not right now. But it appears that magma is creating this earthquakes if I am reading the location properly.

      But we can only wait and see what happens in Krísuvík volcano.

  2. IMO have cleaned up the quake database and removed over half the quakes from the swarm. It’s now looking much more tame! Let’s see how it develops.

  3. why would they clean up there earthquake database? seems a bit silly to take out quakes wouldn’t it?
    or did they only take out quakes that are less then a certain quality?

    1. Because the quakes are annotated automatically in the first round. Computers tend to make errors here (you have the choice between detecting a lot of earthquakes with many false positives versust having a high quality detection with missing some), so this is usually curated by experienced seismologists. If there are so much quakes, this might take a while.
      I think they remove them, because they cannot see patterns or draw conclusions with the false quakes in the image.

      1. Number one reason is overload on IMO’s computers, all references to IMOs pics from yesterday in the papers have been removed.

  4. Peter Cobbold, are you still around?
    What do you think of it so far? Do you see shades of the same pulsing rhythm as at Eyjafjallajökull?

  5. With over 400 earthquakes going on inside of a volcano, this is an amazing time for all scientists, emergency workers and government leaders to gather and learn. Everytime there is an event we can gather more intel that makes us just a little smarter and faster at saving lives. What we learn today in the Geology classroom and in the field is an investment in humanity and our commitment to save live now and in the future.

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