A ML3.2 earthquake (automatic size) happens in Katla volcano caldera

At 18:44 UTC a earthquake with the size ML3.2 and the depth of 2.9 km did happen in Katla volcano caldera (this size is based on automatic data and is going to be subject to a change).

The ML3.2 earthquake in Katla volcano. Copyright of this picture belongs to Iceland Met Office.

Currently there is strong wind around Katla volcano. This strong wind is interfering with IMO SIL network around Katla. But so far no harmonic tremor has been detected after this earthquake.

This earthquake appears to have be formed due to magma intrusion into the rock in Katla volcano caldera. It’s signature on my geophone shows that clearly.

The Z component unfiltered. This picture is released under Creative Commons licence.

The Z component filtered at 1Hz. This picture is released under Creative Commons licence.

All the component on my geophone. This is unfiltered data. This picture is released under Creative Commons licence.

All the component on my geophone. This is filtered data at 1Hz. This picture is released under Creative Commons licence.

This might just be part of normal Katla volcano activity. But it is a fact that it has more earthquakes during the summer and autumn then during the winter. But it is close to impossible to know if this just normal activity or something else. All that can be done is to wait and see what happens.

79 Replies to “A ML3.2 earthquake (automatic size) happens in Katla volcano caldera”

  1. Thursday
    01.09.2011 18:44:27 63.702 -19.303 1.1 km 2.5 90.01 7.4 km NNW of Goðabunga
    01.09.2011 18:44:27 63.660 -19.194 2.9 km 3.2 90.03 3.5 km NE of Goðabunga

    What does it mean when two quakes happen exactly at the same time, still kilometers apart from each other?

      1. What is the mirror made of? Three seconds after the mentioned EQs there was a quake at the Caldera of Tindfjallajökull. My imagination is that there is a big bell at Katla that was beginning to swing first (in infrasound), and a bell at Tindfjallajökull three seconds later began to swing in resonance. Then, what is the bell?

  2. Ok, so I have been looking at the tremor for some months now, and am I right about this?: when the tremors go up, it comes an earthquake straight before it goes back down.. If i’m right, why is this? Is it kinda building up a lot of pressure and then releasing it?:sand also, it seems the higher the red, green and blue goes there, it’s bigger earthquakes!?

    1. Katla takes a long time to erupt. It has had a subglaciel eruptions in 1955, 1999 and July 2011 with periods of increased quakes and tremors since 1999. The 1918 eruption was pretty big and glued things shut pretty good. Apparently, it has a lot of work to do in filling up slowly to the point of no return.

      I don’t get too alarmed when it rumbles like this. It seems to be the pattern…but then one day when you feel adventurous, put on your sunday hat and go for a walk near Mýrdalsjökull and you feel the ground shake and smell sulphur and suddenly hear the sound of rushing water, you say to yourself, “summa beech, the bastard picked my day”

      1. RonF: You know that all of the “eruptions” after 1918 are unsubstantiated don’t you?
        They where probably “just” jökulhlaups or some other…

        Ah, as long as there is rushing water, bring your surf board and shoout “hang loose” and off you go on earths biggest river 😉

      2. Ya, I realize that, but didn’t want to get verbose or too detailed. Wiki also uses the term, “eruption” so I took that license as well 🙂 They could have just been geothermal of some nature.

  3. Hmm, I wonder if those tourists in Thorsmork have felt this major earthquake! It is quite close to Godabunga too. But of course one quake is nothing. There would have to be much more quakes before the eruption.

    Quite windy here, getting more and more as the night falls. Wind gusts have been up to 20 m/s, about 72km/h, but that is the sustained wind in the Westman Islands. Its the post-tropical storm Irene.

  4. Tremors seem steady on increase, but perhaps not reaching that “critical number” (4,000 was at bottom of the BLUE LINES for FIMM last year – unusually quiet start, it was only when it was seen, people became arware of it) usually 5000 to 7000 for other eruptions I have seen. http://hraun.vedur.is/ja/oroi/god.gif
    Forecast for midnight (00:00 UTC) September 2, 2011 and Irene passing to south of Iceland http://www.vedur.is/vedur/spar/atlantshaf/
    IF Katla erupts now to 39,000+ feet, its plume might go to North-East, but I simply do not know its next destination, either Greenland or Norway perhaps.

  5. @Diana!

    Hilfe! A week or so ago you posten a link to a page with a number or longterm cumulative seismic moment plots for Eyja, Goda and Katla. I have lost the link after my bean bowl accident (story on the last blog post)… Sniffle… Could I be a bore and ask for them again?

    If I am demented again and it was some other wonderfull person who posted that link, could you do it again, or if you are totally without blame but saved the link… Well, thanks in advance!

      1. Ah… I tend to agree with you on the divination part of it, but it is easier to divinate if you look at Slysaalda plot instead of the rather noisy Goda-plot.
        Look at 01/09 at around 7 o’clock in the morning…

        On the late night 23d there was a nice one at the more easily read version of Goda:

        But you are correct, it is easier to divinate when the divine talks more clearly 😉

  6. Apparently just a rumble, and the weather is just a little breezy. All is fine, no problem with airplanes or the like. Seriously this must be a coincidental small quake with a near by low pressure system.
    At least I hope so I have work tomorrow.

  7. What’s wrong with this picture? …


    [source: http://hraun.vedur.is/ja/Katla/god_trem.gif ]

    I like the fact that the three frequency channels are separated so they are all more visible than the standard cluttered Icelandic tremor plots in which one channel over-writes the other two … (Why make cluttered plots when it is totally unnecessary? I mean really, the plots are *not* using real paper, lol!) … But even this plot can use improvement for interpreting the seismic data.

    In particular, if the vertical scale were a logarithmic scale, so equal percentage changes in tremor intensity showed as equal distance changes in the plots for all three channels, then it would be more valuable as a tool with which interpret the seismic data.

    As it currently is, what appear to be large changes in the red, low frequency, channel are often *less* of a change, on a percentage basis, in comparison to what appear to be smaller changes in the other, higher frequency, channels (but where in fact the high frequency changes are *greater* than the low frequency changes on a percentage basis).

    Ya see?

    (Caveat: the vertical scale could already be logarithmic, but it is not indicated, and the vertical units suggest it is linear.)

    I wish there were a free utility program which for converting the line plots back to the raw data, so I could replot it using a logarithmic vertical scale, just to se the difference, but the only programs I can find for converting graphs back to raw data aren’t free.

    1. I think I understand what you mean, but logarithms were not my strong poit at school!. I have just refreshed my memory and funnily they seem to make more sense to me now.
      I have always wondered about the vertical scale on these graphs and never felt at ease with it.
      However today is a really bad day for me as I have just had the CSI (crime scene investigation) Unit crawling in and round my car. The perpetrator was “contained” by my husband and his work colleague until the police arrived. So now I am having coffee and deep breaths!
      It’s amazing how watching Hekla can calm one’s nerves!!!

      1. Wow. A car break-in for theft? I’m glad you and car are okay. See, sometimes husbands can be good for something useful. 😉

      2. The Police advisedthe perp to give up crime as a career.:) he is no good at it!
        He was released from prison yesterday. Went to visit a friend. Got stoned out of his mind. Somehow opened my car . Rifled through it. All he found to put in his pocket was a small bottle of my perfume (White Musk!),I had left it in the door compartment. He was overtaken by all this hard work and went to sleep on the back seat! This is where he was noticed this morning by husband and colleague on their way to work. Poor Guy got woken up by the Two burly Postmen, minutes later cops arrived got him on the floor and handcuffed!
        Husband said he enjoyed telling the guy exactly what he thought of drugged up young thieves!!!! According to the police he did a good job of scaring the guy without resorting to violence! 🙂

  8. It will be interesting to see where the latest quake will be placed and how strong it was.

    Due to that it was a large(ish) quake I dont expect it to be downgraded too much but the hypocenter and epicenter might be changed.

    31.08.2011 04:00:04 63.630 -19.064 4.7 km 2.4 33.87 5.8 km NNE of Hábunga

  9. Interesting article maybe someone already mentioned it but okay 😛

    Says an eruption is expected in the near future of Hekla and an eruption in Katla is impending..
    Never seen the IMO say this kind of things. Mostly they only say something when the eruption really is occuring or when the signs are so clear that they can’t fail..
    Probably to save their reputation 😛


    1. Seems like the expression in the article is somewhat “foggy”.

      The Hekla volcano is expected to erupt in the near future and an eruption in Katla is also impending.

      The key word here is “also impending”. They say Hekla will erupt in the near future which can be interpreted pretty much as anything. Can erupt tomorrow or in a years time. Geologic time is like our coffebreaks..Alot longer than you might think. 😉

      And then they say the “also impending” giving the hint that it would also be in a near future which in geological time can be anything between a week and half a decade. 🙂

      But still interesting.

      1. I don’t know. Sometimes the word usage just confuses me a bit. In English (US English) a lot can be “read between the lines” and you can get a somewhat different message that what is stated just by the way a sentence is worded. I’m pretty sure most languages are like this.

        To me, “pending” would be ‘waiting to happen’ and “impending” would be ‘fixing to happen’

        I’m not a grammatical expert, and by many accounts would be a ‘knuckle dragging moron’ just for being from the Deep South (US).

        (“‘fixing’ to happen” would be considered incorrect in it’s own right and is best categorized as a colloquialism)

      2. In British(English) English, pending and impending are very similar. Both mean waiting to happen: “pending” is “awaiting a decision or settlement or about to happen”; “impending” is “to be about to happen or (if bad) loom”.

      3. I agree with you Lurking on this one.
        Hekla has been pending an Eruption since 2006 according to IMO, and I have the feeling that IMO is starting to be a bit pissed off at Hekla for not erupting…
        Katlas impending eruption according to IMO seems to be the same as the consensus here, it has started it’s enging rev-up, but on the geological scale so anything from months to years or decades….

        But this is the first really sharp message from IMO regarding Hekla since 2006 pending eruption notice when they stated that it was topped off and ready to go… I have a vague suspicion that they also are watching the transients as they are building up and chenging pattern. Especially since we all of a sudden have the Geldingaá transient happening.

        They are by the way picture perfect examples of a transient since they go oposite to all other strain-metres. It might though indicate that the eruption will be flanking to the north-east instead of the regular pattern. Normally it is Búrfell that has the hard eruptive transient. Time will tell though.

      4. People in the deep south don’t say “impending”. I’m from Tennessee and we say “fixin” as in “She’s a fixin’ to BLOW”.

  10. A large earthquake did just happen close to Fox Island. The size is about ~7.0. This earthquake appears clearly on the SIL network and on my geophone.

  11. (USGS/NOAA) 2011/09/02 10:55:54 (UTC)
    Preliminary Magnitude: 7.1
    Latitude: 51.758 Longitude: -171.372
    Location: 45 miles/72 Km SE of Amukta Pass, Alaska

  12. @Carl et al
    re Fimm & Ejaf comparative petrology
    Forgive the re-cap, but only just having the chance to catch-up. Are you saying the Fimm magmas are deep mantle derived, cf Troodos complex in Cyprus containing an increased proportion of ultra-basic material, eg peridiotite/dunite and that Ejaf material is ‘upper’mantle/lower crust or that there is evidence of differentiation?
    Could you please,for those of us who don’t know, tell the proximity of these two geographically.
    Also, may be of interest

      1. I suspect would be more exact… I am just guessing here out of my field.
        As far as I can see it is differentiated, with more buffering at Fimmvörduhals and according to Erik Klemetti the ash of Eyja proper is andesitic/rhyolitic mush compared to the basaltic Fimm.
        So, Eyja had evolvaed magma and Fimm juvenile magma.
        But… I am not in any way a geologist, I am even really bad at this. I just noticed that the components where really really different in its chemical set-up.
        But guessing guessing nothing else! 🙂

      2. Carl
        Sorry this is an example of where english (language) gets itself in a knot and offends people. When I said “are you saying…..” it was meant sensu lato, ie a paraphrase of your article – very revealing and interesting ‘cos Iceland could almost be another bushveldt complex with vast mineral resources (WW3 with Icelanders now oops!) – rather than sensu stricto ie a dogmatic statement!!
        Have a good w/e.
        (Captcha – Bekattla dedkofil) perhaps a sign from the gods??!!

      3. Ah, no I got you, it is just that I wanted to make really shure to others that I was just guessing out of my field this time around.

        Risking the WWIII with the Icelanders, yes, on this I am shure, we did after all do 48 drill-holes on a field that we first had surveyed from the surface. The drilling was done with the good memory of the land ownder who got paid for his troubles.
        What we found was quite stunning with a stratigraphic layering of various orebodies ontop of each other. That is flood-basalts for you…
        With 3 different ores ontop of each other we are really itching to do a combine mine. Olympic Dam chalcopyrite ontop, but with a platina impurity instead of the gold impurity that was expected). The copper was what made us drill to beginn with. Directly under that a cryolite strata, then a layer of grey-rock before a rich layer of olivine takes over.
        It made the mining geologists go bandy-legged and play kazoo on their noses.

        Bekattla Dedkofil makes me wonder what a filia you are enjoying if you are into dedko..? 😉

  13. Well Folks! It’s Friday night again. The week end stretches before us.
    I am convinced that volcanoes have an inner sensor that alerts them to weekends.
    Etna is probably the worst culprit, but I am sure the Icelandic Volcanoes also may like teasing us in our leisure time and will not be out shone!.
    So do be careful Irpsit. Think before going trekking!
    All the SIL stations round Myrdalsjokull are showing an upward trend, small, but upward.
    A pleasant and relaxing weekend is wished to all. 🙂

  14. The total number of earthquakes in the past 48 hours seems to have dropped to only 48 as at the time of writing. Is this good – or is something brewing?

    1. The remnants of Irene are passing over Iceland at the moment so there may be exceptionally heavy rainfall?

  15. And since I kind of love this unimposing and gently sleeping giant of Iceland.

    Another quake at Þeistareykjarbunga.
    02.09.2011 17:37:29 65.872 -16.959 5.3 km 1.4 79.94 0.3 km SW of Þeistareykir

    For those who are not intimately familliar she had a 30 cubic kilometer eruption when she constructed the Þeistareykjarbunga Shield Volcano. Oddly enough that eruption is considered smaller than the Thjorsaraun (Veidivötn) 21 cubic kilometre lava-flood. I have never really understood how a smaller eruption can be bigger, but perhaps I am stupid…



    Why it is my favourite volcano?
    “This is Connie Chung at the Test’ikel’bungah volcano…

      1. Jack, I thought you at least would follow the logical error.
        The shield volcano was produced in one single eruption. The volcanos volume is 30km3, hencefort it is really weird that it was produced by a 18km3 eruption… Do you see my point here? Did the lava mashmallow up and inflate post eruption or? I am perplexed at the numbers not adding up… 🙂

      2. Actually you stated the eruption being 30 km3, not the mountain! So your two posts above contradict each other (size of volcano vs. size of eruption).

    1. Seems you got the wrong link from GVP.

      And even if Thjorsaraun (Veidivötn) may have had less ejecta maybe it is considered larger when comparing the rate of ejection? Stabbing in the dark here.
      What i meant was maybe it was more explosive and as such considered a “larger” eruption.

      1. The “wrong link” comment was @ Carl above. It was for some indonesian bump in the ground. 😉

      1. I think either Veidivötn, or that it does not get affected in the same way as Hekla by the pressure emaneting from the Sprungur area. It is also more seismically active which probably relaxes the area above the magma-conduits sufficiently to slow down the cycle of eruptibility.
        But I think they are not that close to each other in how they are constructed. I think Hekla is more complex.

    1. There is one large at 14ish, and the there is one at about 2 to 3 km depth that they found during the rapid lift after 2000 eruption. And then there is a dyke trening in under Búrfell that might, or might not, have a magma-chamber too…
      And then to top it off it is supposedly a rift/dyke/fissure direct feeder also going up the wazoo of the volcano…
      I really really want to see a seismointerferometric map of Hekla with good resolution some day. I have a feeling that it is in many ways as insanely complicated in it’s innards as Etna.
      I think the correct term of it would that it has “a serial progression of tubinged magma-reservoirs that are horizontally and vertically oriented and stratigraphied in a metamorphic transmutative state of change over time and causation”. Or some such… 😉

      Or… Shit happens… and Hekla is big fan!

  16. And while talking about Hekla…
    There seems to have been a shift during the last days in movement at Hekla with both Haukadalur and Isakot shifting in patter. Haukadalur is now moving south-east and Isakot due south.
    Not an extreme motion, but still enough to make me lift my right eye-brow a notch.

  17. Hekla papers about magma chamber…

    Below 14, Chamber count 1

    This one is interesting and infers one at 9km, and it also actually shows and talks about the SIFZ as pressuregiver from the MAR triple junction (damn, I was second on that one…) Chamber count 2

    InSAR analyzis placing the chamber at 14-20km… And a dyke opening up to 5.8km depth. Chamber count 3

    1 at depths between 2-4 and 1 at depths of 40 – 60km!!! Chamber count 5…

    And enter Sturkleton the Confuser (Sturkell)
    Main magma-chamber at 11km. Then he goes into weird with tubinged reservoirs. Enter the Dike reservoir 6,6 times 0,8 times 1,0 inside the 1,5km high superstructure of Hekla making it; “From this it seems that Hekla is presently behaving as a stratovolcano, rather than a typical Icelandic rift-zone volcano.”
    Chamber count 7…

    No bloody wonder we are confused when even the experts can’t get a definitive answer…

  18. And 8, Sigmarsson the GIANT-CHAMBER!

    “The magmatic system beneath Hekla most probably was
    established during the Holocene. The shape and the size
    of the magma chamber may be inferred from the relationships
    between the compositon of the lavas and the
    location of the eruption sites. In a cross-section perpen-
    dicular to Hekla’s ridge, a bell-shaped reservoir 5 km
    wide and 7 km deep appears the most likely; its top
    could be at depth of 8 km according to geophysical data.”


    1. I am starting to have a feeling that if I continue down my by now rather large article collection on Hekla we will end up with 200 different chambers…

      I actually think that my earlier jokulatory term is starting to be more and more correct… Etna and “a serial progression of tubinged magma-reservoirs that are horizontally and vertically oriented and stratigraphied in a metamorphic transmutative state of change over time and causation” is quite correct.

      1. “a serial progression of tubinged magma-reservoirs that are horizontally and vertically oriented and stratigraphied in a metamorphic transmutative state of change over time and causation” LOL! 🙂

    2. Eh… That amounts to >100k km3, i.e. Hekla should theoretically be capable of hefty VEI7 (max. 10% of chamber erupts at a time)?!

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