Posted on by Jón Frímann

Earthquake activity continues in Katla volcano

Even if it is December and Mýrdalsjökull glacier has added around 6 meters of snow on top of it self. It seems that the earthquake activity in Katla volcano is rather strong, even if it winter already in Iceland.


Earthquake activity in Katla volcano past 48 hours. Some of this earthquakes might be frost-quakes due the freezing weather in Iceland for the past few days. Copyright of this picture belongs to Iceland Met Office.

The earthquake activity in Katla volcano is resistant in the Katla volcano caldera and has been that for several weeks already. I cannot interpreted this earthquake activity other then Katla volcano is preparing for an eruption. But when I am not sure at this moment. There is an pattern of earthquakes in Katla volcano caldera, this pattern has been in place since Week 27, but that is the week when the minor eruption took place in Katla volcano caldera last summer (summer 2011).

It is clear that this earthquake activity in Katla volcano is going to continue. I am assuming that this earthquake activity is going to continue until a eruption takes place in Katla volcano. But there is also the chance of the year 1999 event. When a small eruption took also place and earthquake activity remained high for several weeks after that. But after some time the earthquake activity started to drop. For the moment I find that to be unlikely outcome given how long the earthquake activity has remained high in Katla volcano after the minor eruption this summer.

Donations: I am going to try and setup the geophones in Eyrarbakki village and the geophone close to Katla volcano in December. But that trip is going to cost me some money (I pay for the car benzine), but the cost might go as high €157, 1169 DKK, $210, 25.000 ISK (current exchange rates) just for gas (on an car) for that trip. So if anyone can help with this cost it would be welcomed. Thanks for the support! 🙂

Update 1: I am most likely going with the bus. But that also costs some money, around 3900 ISK, 182 DKK, 24€. $32, 20GBP (Current exchange rates).

Blog post updated at 13:12 UTC on 12 December, 2011.

53 Replies to “Earthquake activity continues in Katla volcano”

  1. could it be that the media was not fear mongering, but actually warning of a very real impending eruption of katla?

    1. Impending would mean “in days” or latest “in few weeks”. Katla is not yet that close to the next eruption.

      My guesstimate is Katla will erupt next summer or autumn.

  2. But lisa, all the data is available for everyone, and unless imo have done anything to manipulate the data, there is nothing but the quakes telling us that we will get an eruption, but we don’t know when. Imo would never do anything to manipulate the data either, cause that would be too dangerous. And I really don’t think we are missing anything important. But you’ll never know. But jon, you think that since katla is having these quakes, that an eruption can now come without much more warning?

    1. This is about much warning that we get. But there are going to be larger earthquakes before an eruption if it is a large one. At least that is what history tells us.

      1. Enough to be felt in Vík, and annoying people for some days. Judging from past reports.

        But I also expect deep earthquakes getting shallower, and sudden inflation, something that has not happened yet.

  3. But doesn’t that all depend? Has there not been eruptions before without big quakes as warning? What about the one in iceland this year? What happened during the run-up there?

    1. Most volcanoes seem to have there special imprints re. how they are warning (or not warning) before an impending eruption.

      It wasn’t Katla, but Grímsvötn which has erupted this spring. And yes, there have been warning signals, inflation, earthquakes, harmonic tremor and especially a glacier run last year, so the scientists have seen it coming. They even went so far as to put a special new page re. Grímsvötn eruption on the website of Institute of Earth Sciences with University of Iceland (last winter!). As Grímsvötn has been erupting so often, it also is a very well studied volcano.

      With Katla eruptions, it is a bit different. We have not real scientific reports about former big eruptions, because the last one was in 1918. But there are reports of people observing former eruptions in the region, and they were always writing about some very strong earthquakes – 4 to over 5 on Richter, estimated from damage discriptions in the reports – happening before such an eruption took place (e.g. in 1918 and 1755 – W. Schutzbach: ”Katla. Saga Kötluelda.” Reykjavík 2005).

  4. Donation on its way Jon!

    Is it my imagination/lack of experience or have some of the Katla region SIL stations been showing harmonic tremours over the last few weeks?

  5. Am I correct in thinking that the extra weight on the glacier would increase the pressure of the magma or won’t it make that much of a difference?

    If that does happen, i’d expect some sizeable quakes when the Spring Thaw takes place and the weight on the magma drops.

    1. It is not a big difference. As Jon said, there is now 6 meters of fresh snow, which would eventually turn into o,5 – 1 meters of ice (no melting assumed). Remember, there is 3-8 km of rock below the ice, until you’ll get into the magma chamber. And, weight of 1 km of rock equals weight of 3 km of ice (roughly).

      1. I really don’t understand the pattern of increase earthquake activity (and even many more historical eruptions) occuring during summer and autumn months, compared to winter months.

        This is quite clear pattern that it does occur.

        But the difference in the ice added is very small. Most of the glacier underneath is supposed to be solid thick even during summer, why would the little melting occuring at its top influence the magma underneath.

        It shouldn’t but the fact is that there is a seasonal peak in activity in Katla over the summer time, and this is not observed for any volcano in Iceland (even ones under glacier, like Grimsvotn or Eyjafjallajokull)

      2. Forget about the ice thickness.
        Think water pressure.
        Melt water collects down there in late summer increasing pore pressure.
        When the kettles emptied last summer there might have been ca 200 m water level drop in pressure.
        Then there are increased melting both from increased geothermal and increased surface areal due to all the crevasses round the emptied kettles.
        Water induced seismicity like we see in Hengill might be a part of earthquake activity specially when most of them are that shallow.

  6. Shes getting ready. I dont think the bbc was scare mongering. So what if they were really. No one can say what she is going to do or when 😉

    2. Yep, scaremongering.

      Any mainstream media, and a lot of the midstream media, are total buffoons. They don’t fact check, and they don’t look at the actual real information. All they seek out is some bobbleheaded idiot who makes some sort of pronouncement.

      Until they offer up non glitz seeking scientists who give you the range of likelihoods, and don’t spin it for the highest “OOOOHH!!!” factor, it’s total B/S.

      Your best bet in that situation is to read/learn and look for yourself.

      1. OT: We had a local parade here in town. Happens every year. Did the local TV station even mention it? No. They were too stuck on what starlet was fleeing from the law and running their advertisements. In order to see TV coverage of the parade, we had to go to a TV station broadcast out of a nearby town… 50 miles away.

      2. I am afraid that sort of thing is international Lurking. There seems here to be no sense of real community any more and outsiders are running our local media!!

      3. Our local radio used to be great fun. Prize giveaways, phone in requests, debates, buy and sell etc. Since around y2k it has become a what seems a Robo-Station void of any public input whatsoever. Quite disconcerting especially with the richest man in our province owning nearly all the stations on the map. Sigggh, Sorrily I did poorly at the game Monopoly as a child. Bruce the ungreedy.

  7. Jon, can you explain the frost quakes? I wonder why there are hardly none at vatnajökull? It’s really cold there and he has glaciers in higher and lower altitude.

  8. There is something else that I have been observing in Katla. Deep earthquakes have been on the increase in recent weeks and especially last days. Earthquakes like between 15km and 5km, below the magma chamber, meaning fresh magma is rising upwards.

    I was expecting this to be the before-the-last sign before the big eruption of Katla.

    After this, I expect to see deeper earthquakes becoming stronger and shallower, and also followed by sudden inflation, something which has not occurred yet.

    So, I think the changes are good for a large eruption of Katla in the next months. But no one can really know how long this process will take, can be weeks, months or a few years. With the neighbour Eyjafjallaj0kull, the deep earthquakes started a couple of months before the eruption.

    1. @ Irpsit. I agree there has been no real inflation to date yet as you say there are indications that magma is on the move deep down. I am still intrigued by the graph at Eystri- Skogar .
      http://hraun.vedur.is/ja/oroi/esk.gif
      Is it possible this is magma filling a dike, sort of an “over spill” from the magma chamber in Katla?

      1. There is a magma chamber (which is nothing like a magma lake but rather a series of magma fills) somewhere around 4km. This extends towards surface in form of dikes, breaking through the rocks.

        Then, below that, there is possibly thick crust at the place of Iceland, down to 20km. And some deeper magma reservoirs which feed the upper chamber. It could even be that these deep reservoirs could feed both Katla and Eyjafjallajokull.

        Magma has been pushing near the surface of Katla for many years, but if we see a fresh influx of magma now (at least it has already happened with Eyjafjallajokull) this could mean a large eruption in the nearer future. But this is happening, this new magma hasn’t arrived yet near the surface, because there is no significant inflation.

  9. My guess is July. My last two trips overseas coincided with the last two big eruptions. My next trip is in July. Obviously, that’s not a scientific guess but that’s what my money is on for now.

    1. @Bruce
      I always lost at monopoly too. This must have set a precedence for the rest of my life. Overly honest, trusting and declaring all my taxes and yes! A loser as in lack of money….The only thing I have never got is a real go to jail card!! However unlike some I used to play with, I am happy and don’t have to look over my shoulder all the time!!

    2. That is a very scientific guess Mountain Man. It follows the Law of Sod or Murphey. 🙂

  10. I dreamt abt a volcano erupting last night; may have been katla!! Two things: it was a fissure eruption for ages then the whole thing exploded. There was a gang of school kids or other proffesionals close by (i was one of em). Bear in mind im a lickle bit psychic!! Im officially bonkers! 🙁

  11. @Lurking:

    Any time to do a quake depth vs. time plot for Katla, A) for the last 2-3 years, and B) from May 2011?

  16. Update on the geophone install plan. Due to the fact the Christmas are next week, the installation of the geophone at Skeiðflöt (Katla volcano) has been delayed until January 2012. The bus schedule for the south Iceland does not allow me to install the geophone in that area before Christmas.

    The geophone for Eyrarbakki is planned to go up next week as I did originally plan.

    1. Hey Jon,

      If you install the Eyrabakki or Katla geophones during an weekend, please let me know. I live close to Eyrabakki so I would be glad to give you an helping hand. But I don’t have a car to drive to.

  17. Katla will erupt in the future. Nobody can say when, or how. Like Jon says, it’s probably building up for a show, but it could easily still be weeks, months, or years until it erupts. The media does like a story about a disaster, so that’s why they use words like “Imminent” and “Overdue”. I would not put much faith in prediction, just be vigilant.

    Looks like El Hierro hasn’t stopped with its show yet either!
    http://volcanoscience.blogspot.com/2011/12/quakes-stop-at-el-hierro-but-eruption.html

  18. I have heard from seperate sources that there is no inflation in katla and in others that there is…. what is the truth?! Secondly; how can inflation be measured when its covered in ice? Doesnt the ice melt and rebuild constantly…. surely this would give an inaccurate reading?

    1. There is inflation if you look over several years (overall long-time inflation trend). There is no inflation, if you look the last few months only (pre-eruption “last-minute-inflation”).

    3. Katla volcano has inflated. But now the inflation is most likely at is high end of the total amount the magma chamber can store. This has been going on for several years now.

      I do not expect more inflation to take place in Katla volcano. But there might be localized inflation however. It seems to be taking place at this moment in Austmannsbunga for instance. Or at least it was.

      1. Hm. I did not know about that.

        However, I think the pressure is probably not enough yet.
        Otherwise, it would have had already a full blown eruption in July, when magma leaked out to surface.

        I think the chamber is full, and as new magma has been pushing recently from depths (some quakes in recent days down to 15km), it will eventually not hold anymore, and result in large quakes in shallow depths (the ones mentioned historically)

  21. For those who enjoy playing with contour maps and are interested as to what Katla and all the other volcanoes hidden by ice caps look like this is the best map ever! To see the contours under the glaciers press the “Atlas” button
    There is also a fascinating infra red view of Iceland.
    Enjoy!
    http://atlas.lmi.is/kortasja_en/

    1. I’m pretty damn sure those contours are for the surface of the ice whenever the ‘atlas’ was made. I’ve seen 3d renderings of the terrain under the Katla Ice and those contours do not look remotely correct.

  25. What is happening few kilometers NNE of Hellisheiðarvirkjun. In recent months, there are series of earthquakes, almost always located at the same depth and in a very small area. Can this be caused by energy plants or it is magmatic origin ?

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