Posted on by Jón Frímann

Small eruption took place in Katla volcano in July 2011

According to the news on Rúv this evening it is now a opinion at Icelandic Met Office that a small eruption did take place in Katla volcano during the days 8 and 9 July 2011. This eruption was however larger then the eruption in Fimmvörðuháls in Eyjafjallajökull volcano last year (2010). But this is based on tremor data from around Katla volcano during this summer. But this is what Einar Kjartansson geologist at Iceland Met Office says in the news at Rúv this evening. Even if this small eruption did take place in Katla volcano it does not seems to have eased the pressure inside Katla volcano, so a large eruption in Katla volcano is still a possibility in the close future. Note: GVP has updated Katla volcano eruption status to the year 2011!

This conclusion was reached by checking out the cauldron that formed during this event. But they show a sign that they had a sudden melt taking place. But that melt can only happen of lava got into contact with the ice and fast melted it. This is also the reason why there was a 5 meters flood in Múlakvísl glacier river that did destroy the bride over it. But it is also a fact that the harmonic tremor in Katla volcano during this period was the same as that did happen during the eruption in Eyjafjallajökull volcano. The only difference was that it it was stronger from Katla volcano then in Eyjafjallajökull volcano it seems (at least from what I can see from the data). Even if it lasted for a shorter time then in Eyjafjallajökull volcano.


The tremor on Slysaalda SIL station on 9 July 2011 at 00:36 UTC. Copyright of this picture belongs to Iceland Met Office.


Alftagrof SIL station on 9 July 2011 at 00:36 UTC. Copyright of this picture belongs to Iceland Met Office.


The area that was active and had a eruption on 8 and 9 July 2011. Copyright of this picture belongs to Iceland Met Office.

Even with this small eruption it is clear that Katla volcano is not done with its eruptions. Since the large one is not yet over. When that happens is a good question and nobody has a answer too at the moment.

Note: This is also what did happen in Hamarinn volcano the week after. But I also think that volcano did have a minor eruption in July 2011. As the signatures are the same from what I can gather. So that makes three eruptions in Iceland for the year 2011 if confirmed later on.

Icelandic News with this. Use Google translate with care on it. Since it does not understand.

Allt bendir til Kötlugoss (Rúv.is, Icelandic, Picture)
Segir Kötlu hafa gosið í sumar (DV.is, Icelandic, Picture)
Lítið eldgos í Kötlu í sumar (mbl.is, Icelandic)

39 Replies to “Small eruption took place in Katla volcano in July 2011”

  1. Oh my… anybody who remembers when I made my famous bet?
    Was it before or after the mini-eruption?
    Becaue if it was after I guess I need to go and make a hat and a portable grill to barbeque it on, of course starkers and infront of the Búrfell Dalek. I wish that I had known it in July… Starkers in september wont be fun, not much to watch for the ladies in the cold.

      1. Ah, you just saved everyone from going blind.
        To quote Lurking”
        “What you have seen you can not un-see.”
        If Katla goes before Hekla I seriously hope it will be during the summer. But with my luck it will be in January and a snow storm starts as soon as I disrobe…

  2. After Jon’s report it seems to me that Katla has gone before Hekla and you, Carl, have some activities to perform …lol

    1. Well, the bet was made after the mini-eruption so I think it is not vallid.
      Seattleite just saved the Ladies eyes by proving that the bet was made on the 15th of august, well after.

  3. We can say that… the “Fimmvorduhals” of Katla and Bardarbunha happened in July 2011!

    I would really like to have seen how would those lava fountains look under the thick 500 meters ice cap or both Katla and Hamarinn. And remember the flood in Hamarinn was larger!

    Obviously, these volcanoes still have a large amount of magma ready to erupt. This could be the beginning of a rifting volcanic-tectonic episodes in both Katla and Hamarinn. Small eruptions on and off for a period of some years.

    In these small eruptions, the magma comes out, carves a cave under the glacier and can come out in a relatively large amount, causing only a flood, and no ash cloud. If more magma comes out, it will melt more, but it will not explode if it keeps coming gradually. Because I think the ash cloud is only when the rush of magma is large and at once, and the water pours into it, cooling it fast, and so it will blast as rocks and ash. Now, we have a different situation.

    I wonder what follows when further magma erupts. Obviously if magma keeps coming out, more ice will melt, and a larger part of the glacier will tend to collapse down. But the glacier could hold well too. If the ice collapses, I don’t know what follows if magma only comes gradually. Water can accumulate like it happens in Grimsvotn. I guess this will make the future eruption more explosive. It remains to be seen if further floods will happen in Katla.

    But also the ice could be carved, leaving an empty space between the heated ground and magma coming out, and the ice above it, like inside a cave. This could also allow for more magma to be released, without causing explosive behavior! Gentle eruptions of Katla. Something like it happens in Krafla, but beneath the ice.

    But now, notice this. I am not surprised that a large eruption has not happened yet. There were no deep earthquakes, like it happened in Eyja. So, there is no sudden rush of deep magma triggering a threshold or pressure upwards.

    Any comments?

    1. Krafla volcano does this. But Krafla volcano is in my view close to or the same type of voclano as Katla volcano. There are differences. But they type os more or less the same.

      The main difference being that Katla volcano seems to have andesitic and rhyolitic domes on the loose. Both known and unknown one. That is a bad mixture in the otherwise basaltic type of magma that Katla volcano has.

      I am also expecting more smaller volcano events from Katla volcano at any time, without any warning. Given this data that have been confirmed.

      This also means that there was a small eruption in the year 1999, so this is just short of 12 year break between eruptions in Katla volcano. A really short break it seems.

      1. Difference also being that the norm for Krafla is rifting eruptions, and central vent eruptions being the exception. And Katla has central vent eruptions as norm, with rifting eruptions as the exception. Also the lavas extruded are very different in their chemical composition. An iced over Askja would be more like Katla as a comparison.

      2. Is this basic difference due to the directions of rifting? I mean, at Krafla, the ridge is only widening while at Katla the halves of the ridge move mostly along the rift axis?

    2. I have one comment…
      I will laugh my ass off if this is what Big Bad Katla serves up for an eruption after 93 years of dormancy, and then go back to sleep for another ninety years… 🙂
      Would be perfect after all the Katla scaremongering if this was all, just a cuddly little sub-glacial eruption together with a not to big Jökulhlaup, like a burping child in her sleep. And then nothing more…

      Do I believe this? Not really, but it could happen.

      1. I do not think this was it. Not at all…

        We have had other symptoms after that, e.g. sulfur smell, conductivity changes, inflation, earthquakes, etc.

        I think Katla is still on the track for a major eruption before end of next year.

      2. I agree with both sides, my humble opinion is, there was very few if any deep EQ’S and nothing else has happen since july on the same scale.

        The other side of the coin is, pressure is still there and they are small floods, sulfur smell etc… they did add more stations and in Vic, they evac test after.

        If things are ready, the next few months will add weight to either side. My bet is, things need to get allot more active, I think the professional people, have allot more non-public info and might have the answer already.

        I think a VE-0 does not count for Carl and i agree that Helka will go first and Katla is a long time away.

  4. Does the IMO (or other scientists) do isotope analysis to to check for the signatures of an eruption? It should be possible to air or water sample, extract the sulfur or carbon (or possibly oxygen) to check for any difference to the normal background, as the sulfur-32/sulfur-34 or carbon-12/carbon-13 isotope ratios as emitted from a volcano are different than those from other sources.

    1. Uranium isotopy would also work well, since the uranium isotopes are different from a volcano, and also gives a good measure of the depth the magmas are originating from.
      Also any REM content above threshold would do, there is after all an enormous difference in REM content between the hotspottish volcanos in REM content compared to the others. Take Askja for instance, she has 2 orders of magnitude higher content of REMs than Theistareykjarbunga, and they are still on the same line. Krafla is one order of magnitude lower than Askja, but Kverkfjöll is an order of magnitude higher than Askja. Kverkis and Bardarbunga has the same amount by the way. I have never seen any REM count from Grimsvötn though. Hard to get samples of the lava, tephra is not good for this, in theory you could though take a sample of Laki lava, but I have not access to any REM count for Him. (Grim is a boy volcano).
      Odd exception out is as always Thingmuli, but that volcano is a joke in so many ways. 14 types of lava that is not even remotly close to each other between two consecutive eruptions. A mining geologist said that he believed that volcano had more than two separate conduits leading into it. For instance, two layers of basaltic lavas ontop of each other, one with high cobalt values, the next eruption had almost none… Weirdness… Most intriguing is though the chunk of porphyry brecchia lava (how the Godabunga did that happen!?).

  5. Found a rather nice little paper on the geochemistry of Laki lavas. It has a good representation of seismicity during the Laki-eruptions (they count ten eruptions) for this interested, Irpsit this is for you.
    But sadly no REM or other isotopy.

  6. I’ll be in Vik on October 9th and 10th. I’m not sure I’ll be able to sleep very well… you know with my anxiety over something like DROWNING in the middle of the night from a glacial outburst.
    Nah, I love it! I sort of hope she grumbles while I’m nearby. I’ll sell my Airwaves ticket if I’m in Reykjavik and she decides to go off. I rented a jeep for this!

    1. Don’t worry too much. The people in Vik are well prepared for this – just follow their instructions, if anything happens.

      1. The flood will not get to Vík, unless it’s the big eruption, and it is an especially big one (and even with that I am not sure whether the flood will reach Vík). Otherwise even large flooding like it happened in July stays about 7km east of Vík.

        You should not worry about it, and just discover the beautiful area around Vík.

        Like I say, Katla will have a rush of deep earthquakes becoming shallow, something that did not happened yet, but it seems to be happening in the Canarias Islands volcano now.

  7. I’ll be in Vik on October 9th and 10th. I’m not sure I’ll be able to sleep very well… you know with my anxiety over something like DROWNING in the middle of the night from a glacial outburst.
    Nah, I love it! I sort of hope she grumbles while I’m nearby. I’ll sell my Airwaves ticket if I’m in Reykjavik and she decides to go off. I rented a jeep for this!
    Anyone else going to be in the area?

  10. Good morning everyone 🙂 Hmmmm! If Hekla erupts, would the heat be felt where the Burfell Dalek stands? If so Carl could wait until then for his dancing. It will give me time to order a very powerful magnifying glass to place over my PC monitor and will make for more interesting watching. 🙂
    Jon could sell tickets for the event and so make some money:)

  13. Looks like its a bit of weather pushing up the high frequenzy plot. The low frequenzy (0,5-1,0Hz) seems to be pretty stable. Winds according to IMO is around 10-15 m/s and on the top of the glacier I bet there is quite a bit of gusting.

  16. Jon – what about the deflation at Austmannsbungu?

    that is over an inch in less than 48 hours ….

  17. Sorry could not get Google to translate.

    Why does it take so long to work out whether or not an eruption has happened? Is this an issue with the definition or the fact that it happened under the ice-cap so not easy to interpret?

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