Posted on by Jón Frímann

Large earthquake swarm in Katla volcano

At 02:45 UTC a large earthquake swarm did start in Katla volcano. I do not know if this an start of a eruption in Katla volcano or not. For the moment it is too early to know for sure. I have to wait few more min before that becomes clear on the harmonic tremor plots. The largest earthquake so far according to the automatic SIL systems is a ML3.9 earthquake.


The earthquake swarm in Katla volcano. The second green star is from a fake ML3.3 earthquake from yesterday. Copyright of this picture belongs to Iceland Met Office.


The harmonic tremor plot on Slysaalda SIL station at 03:04 UTC on 5 Október 2011. Copyright of this picture belongs to Iceland Met Office.

It takes a few moments to become clear if Katla volcano is starting a eruption or not. I am going to post updates as this situation changes if I have too.

493 Replies to “Large earthquake swarm in Katla volcano”

  1. The earthquake activity now is stronger then normal from what I am seeing. The earthquake swarm activity is also starting in other areas of Katla volcano caldera.

    For those how where wondering about the eruption prediction. I was trying to use the old sayings about the earthquakes. But those documentations might not have captured what did happen earlier in the process too a Katla volcano eruption.

    But I now fully believe that is what is going on. This just has not been observed in this high details as is done today.

    1. Nice one!

      Two focal points of the earthquakes it seems. Still miss all the godabunga cryptodome action though. And the southern tip seems to have gone more or less quiet again.

      1. Carl, if i may throw a rock into the cake. We have seen some deeper EQ’S in the last 10 days.

        Some hot rocks are melting the ice\VE0 event, that might of caused this summers issues. Up is not the only direction.

        I understand that no harmonic action was detected today/last night, could the fluid been doing down or move towards the dead zone and not cause the “normal” spikes?

        I agree with the idea of the getting gear over to the dead zone rather than the other one.

        PayPal issues, Jon. Some funds are on the way.

      2. I did not really get this. 🙂
        Yes, up is not the only direction.

        Yes, I agree with the deeper quakes, but, I still say we are far from an eruption. But I might be dead wrong about that… 🙂

      3. sorry, my bad. The main point i was making is.

        Maybe the Magma is retreating back down the vents as there is not enough energy to crack the top.

        Just guessing, but it could be starting to back to sleep.

      4. Neither Rick, it is just resting a bit before continuing it’s labouring. Soon a beautifull eruptionbaby will be born.
        Actually, think of what we are seeing is the terminus of giving birth. The quake-swarms are the cramps, the Jökulhlaups is the water passing. Problem is just that we have no clue how many birthing cramps is needed before our fiery baby is born.

      5. Well the only way magma under pressure can go is forward right? Even if it goes “down” it is still moving forward through existing conduits, weak structures (causing swarms). I have a hard time believing that the pressure would decline to such a degree that the magm would retreat.

        The deep quakes could probably be cause by the entire magmatic structure beeing pressurized to the poing that fractures occur at greater depths just as they occur at shallow depth.

        Katla has a tightly screwed on lid and will probably need alot of pressure to blow it. Until that happens I wouldnt be surprised if we will see fracturing on many levels (though the main body of magma will move upwards)

      7. Yes, thats it Carl. my thinking is connections between Katla and fissues outside the normal volcano.

        You wrote about Laki and how its time has passed for now. The area today and last night did not have any hots spots or past where eruptions, that i could fine.

        Also over the few months, the EQ’S have gone around in a circle, if you are looking down on the 2D map over time, like what the gif did today.

        The pulsing that is happening every 15+ hours
        just agree that more info and eyes is need were the the last fissue happen.

        Just thinking out loud, cheers for answering with respect and excuse my grammar and spelling.

      8. Daniel, magma can most definitely retreat again. We saw this most dramatically at Pu’u’O’o recently. Most likely causes probably include rifting which opens up space underground for the magma to flow into.

        In fact I have a suspicion that there is a lot more movement of magma going on than we are aware of. If back and forth movement sets in on a fairly continuous basis, which you might see under an active volcano like Katla, this movement will erode pretty decent channels along which it can move and, more importantly, there might not be a lot of tremor associated with this movement because the subterranean channels are for all intents and purposes “open”. This might explain those eruptions that seem to burst out of nowhere with no precursory tremor.

        /just some idle speculation on my part

  4. A translation by Google from: http://www.ruv.is/frett/snarpasta-hrinan-i-kotlu-fra-2002

    “Simultaneous Pasta launched Katla in 2002

    Seismic eruption that began in the Katla caldera just before three o’clock at night is the instant pasta which has occurred since 2002, according to data from the Meteorological Office. There was a large number of tremors in the night; some of them larger than three points. Have decreased activity in Mýrdalsjökull today, but if TREMBLES ground for twenty minutes. Geologists are still in service to the earthquake of last night and this morning.”

    Instant pasta does not sound good for you; causes bad indigestion.

    Could an Icelander please tell me what “Snarpasta” is? Thank you.

    1. Would seem so. All stations seems to have different degrees of increase. GOD showing the largest increase for obvious reasons.

      Looking at the webcam it is hard to imagine the absolute turmoil going on below. It looks so serene and quiet. 🙂

  6. Now it’s steam i see!!! It’s compleatly different, the wind blows it like a chimeney, isn’t it?

      2. No worries, it is easy to spot for a snow-storm used Swede… Survive a few of them and you get to recognise snow-storms and snow-drifts in high winds. If you do not, then you die.

  7. It’s probably just me not remembering exactly the view but I’m sure the area of ice above the promontory of ice on the Katla view just to the left of centre looks like it’s different from this morning – the shadowing is much more pronounced as if the contours have changed

      1. I’m not thinking anything eruptiony about it – it’s just it looks like a more pronounced back to a cwm-like formation in the ice (I know a cwm technically is a post-glacial formation) – it was just the first thing that I saw when I put the webcam back on this evening as this morning Myrdalsjokull looked fairly consistent in its whiteness.

    2. Maybe because during the day the lightsettings and intensity changes. This mixed with changing snowlevels/position tricks the eye(s).

      Henk

    3. I’m a Finn, and I’m used to snow every winter, just like Carl. And I can confirm the things you’re seeing, are just snow playing tricks with your eyes.

      Want to learn it yourself? Move to Finland (or northern Sweden) for a few years, buy a car here, and drive tens of kms daily, both during daylight and the dark hours…

    1. Ophelia will hit Sweden today, and Finland during the night. Expected wind at 20-25 m/s and gusts at 25-30 m/s…

  9. As some has said earlier. If you need to ask yourself IF Katla is erupting (steam) then it is NOT.

    When Katla blows it will be very visible with a very explosive initial phase. As the magma will flashmelt alot of ice in a very short time I think there will be alot of ash and depending on the force of the eruption a high plume.

    A plinian column is probably not too improbable. At least a sub-plinian and if you see that on cam..You wont have the need to ask IF it is erupting. 😉

    1. I could not have said it better.
      Yepp, minimum a sub-plinian. Hard to mistake a 15+ kilometre pillar of ash, fire, brimstone, and huge lava-bombs flying around. Think Hell opening up.
      A little steam is not it.

    2. Excellent summary Daniel!

      The animation by Lurking makes it clear that the lid over the magma chamber is cracking (i.e. the eqs) along its edges. From the graph showing accumulated energy release, it’s clear that the pressure below is tremendous. Right now I’m asking myself the following questions: What is the chemical composition? How much gas and volatiles are present in the mix? What percentage of magma in the the magma chamber is eruptible? If the answer to the first is andesitic-dacitic and there are large amounts of gas in the magma as well as a large percentage of eruptible magma, this could be big (and I mean VEI 5++ big) if the magma chamber blows. But if the answer to the second and / or the third questions is “little” and “low”, Iceland may get away with no more than a large VEI 4 even if it involves the main magma chamber.

      When? Could be tomorrow or in 50 years’ time. I doubt anyone could say which with any degree of certainty and if they do, they’re taking a wild guess! 🙂

  10. maybe its just the webcam, as its not very clear, but there appears to be black ‘smoke’ below the glacier at eyja and there appears to be a red ‘glow’ to the lower right of the picture. anyone else see this?

  11. The amount of increase in cumulative seismic strain release for Katla during the last 24 hours is almost ridiculous.
    The amount of energy released since 1996 is 1,2e+14 today the release has been 0,8e.
    Another way to put it, 0,7 percent of the total energy release during the last 15 years has happened today. Or a nuke dropped if you prefer that comparison.
    http://hraun.vedur.is/ja/Katla/myr_allt.html

      2. Btw, Grimsvötn had a seismic release during 48 hours of 1,5e compared to 0,8e for Katla.
        Caveat:
        We do not have the information of needed cumulative strain for Katla to make any comparisons really.

      3. That last jump was the actual eruption itself. The days before were actually unusual quiet.

  14. I said that and you’re right… although… July! A sub-glacial eruption can be an eruption, with little or no visible manifestation until someone gets up there and looks for holes in the glacier.

    If she erupts properly then yes, it’ll be obvious to everyone!

    Mike

  17. To divert attention back to the grand pumping experiment at Hengill… Does anyone know how deep they are pumping this time? Its just that the last 3 EQs have been measured at between 5.2 – 6 km deep, and the magma reservoir is estimated at @7km deep. Are they fracking thier way downwards I wonder?

    2. I’ve not (can’t recall it at least) seen any official or public depth

  18. I’ve noticed a pattern. You get few really deep quakes 15+ km and then within a week there is a big swarm.
    Could it be that the big quakes pump up fresh magma and the resulting large swarm that happens at the shallower area is just the chamber swelling. Pressure building in the magma chambers, enough to cause cracks and leaks etc but not enough for a full scale eruption. Maybe a few cracks have allowed a little magma to get closer in the past – close enough to melt some of the Ice cap.
    If this is the case then surely sooner or later the pressure will be to great and then… boom!!

      1. Nope, earthquakes are single spikes, if you look closely you can see the all the frequencys being up for a several minutes (?), which is too long to be just earthquake noise.

  22. A boy died in a blizzard, in june 2005, just a few miles from the safe hut at Hrafntinnusker.
    Mid summer, so even then you have to be careful in the highlands! There has been a memorial erected for him.

    Henk

    1. Should have been an addition on Carl’s comments about the snowstorm.

      Henk

    2. Yep! I saw that memorial during my hike from Landmannalaugar in early july last year. Pretty scary when you’re the same age, in the same place, around the same time of year, alone.

  24. i am coming to iceland on saturday 8th october 2011 for 2 weeks touring round the island….is it going to be safe with the possibitly of Katla erupting?

    1. Yes, absolutely. *If* Katla would erupt in this time, you can simply spare the south of the Island by not going further than Hella/Hvollsvöllur or Seljalandsfoss. There are plenty of other things that you can see and visit instead. I would worry more about the weather though.

  25. i am heading north once i arrive, Borgarnes then onto Saudarkrokur, Akureyri, lake Myvatn, Egilsstadir, Hofn, Vik and finishing up at Grindavik. I was over for a visit Feburary 2011 and toured the south and west and fell in love with the place. I have been keeping watch on the weather etc via IMO. Is the weather going to be bad???
    as in snow???

    1. You have to prepare for one thing only: The weather can change totally within an hour from a summer day into hellish winter storm. If your guide or local contact does not account for this, take another one, a more experienced one.

  26. (Corrected English version for you Jon. Love your posts, but the English drives me nuts! If you like, I can be your shadow editor, since I am extremely bored!)

    Not a lot has changed in the past few hours since the earthquake swarm started in Katla volcano. An eruption has not yet started in Katla volcano, when it might start is still a mystery.

    Here are some traces from my Heklubyggð geophone. Currently that is the geophone that I have closest to Katla volcano. I am collecting donations so I can buy two new geophones, your help is appreciated. The blog post about that can be found here. I don’t expect to have the geophone in place before an eruption starts in Katla volcano this time around. So far, the donations are up too 5,410.74 DKK, so I am not that far from what I need to collect in order to purchase the geophones. I don’t have to pay customs for this according to an email I got from the customs office when I asked about it. But I have to pay 25,5% VAT on this when it gets here. That might be a good amount, I think, in Icelandic Kronas (ISK).

    One of the largest earthquakes (above). This is not the strongest earthquake in the swarm that took place this morning in Katla volcano. This is also a double earthquake; that is two earthquakes taking place at the almost the same time. That is the reason for the odd looking wave form on this earthquake trace. This picture is released under Creative Commons licence. See Licence web page for more details.

    A ML3.0 earthquake that took place in Katla volcano this morning. This picture is released under Creative Commons licence. See Licence web page for more details.

    The largest earthquake in the earthquake swarm this morning. Its size was ML3.55 with a depth just short of 1 km. This picture is released under Creative Commons licence. See Licence web page for more details.

    A ML2.94 earthquake in Katla volcano this morning. This picture is released under Creative Commons licence. See Licence web page for more details.

    So far it has quieted down in Katla volcano, but that doesn’t mean a whole lot, as magma can go on the move at any time, and without any warning at all. So monitoring Katla volcano is important, with that fact in mind. According to Iceland Met Office, this is the largest earthquake swarm in Katla volcano caldera since the year 2002.

    I am expecting more strong earthquakes to take place in Katla volcano, but it is impossible to know when a new earthquake swarm might start, and how large/long it will last. For the moment, we’ll just wait and see.

    Iceland Met Office has put up a news about this in English. Thanks too the readers how pointed this out!

    1. I cans ee your not familiar with the field of volcanology, as you have errors in your version…

    2. It is Jon’s content that is essential and also to get it as quickly as possible. I would therefore rather read Jon’s instant text as is without proof reading.

  28. Is there a chance that all the pumping of water down to near Hengill’s big magma chamber and all the earthquakes it creates might aggravate Hengill into an eruption??

    James

      1. Do you mind not being so short. Either elaborate or don’t answer to my question at all.

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