Posted on by Jón Frímann

Small glacier flood from Mýrdalsjökull glacier (Katla volcano)

During the night (and when I had unstable power) there was a small glacier flood from Mýrdalsjökull volcano. Some minor harmonic tremor change was detected following this glacier flood. This even was small one, many times smaller then what did happen on the 8 to 9 July 2011. Due to security concerns the Civil Emergency Authority did close the main road in Iceland for this area. Since they never know how big the flood can actually be. The main road was closed for about one hour. This glacier flood was detected around midnight 20 to 21 July 2011.

This flood is actually so small it is hard to see it on the harmonic tremor plot from the SIL stations around Katla volcano.


Tremor plot from 07:50 UTC this morning. It is hard to see the harmonic tremor from this minor glacier flood. Copyright of this image belongs to Icelandic Met Office.


Tremor plot from 07:50 UTC this morning. It is hard to see the harmonic tremor from this minor glacier flood. Copyright of this image belongs to Icelandic Met Office.


Tremor plot from 07:50 UTC this morning. It is hard to see the harmonic tremor from this minor glacier flood. Copyright of this image belongs to Icelandic Met Office.

What happens next is impossible to know for now. But it seems that activity continues to be high in Katla volcano. All that can be done is to wait and see what happens. But I am going to continue to monitor the changes in Katla volcano as best that I can do until I finish my summer job (29. July).

Icelandic News about this.

Aukin leiðni í Múlakvísl og órói í Mýrdalsjökli (Vísir.is, Icelandic)
Náið fylgst með Mýrdalsjökli (mbl.is, Icelandic)
Hringvegurinn opinn á ný (Rúv.is, Icelandic)
Breytingar í Múlakvísl (Rúv.is, Icelandic)

425 Replies to “Small glacier flood from Mýrdalsjökull glacier (Katla volcano)”

    1. Very useful. My list of geology-volcanism links for Iceland keeps increasing!

    2. Thanks G1 – the IMO site is clearly full of useful info. I often click on a link that someone else has posted like the one above and there is fascinating stuff there. However I struggle to find these pages from the main IMO – has anyone got a list of these links?

      Other charts I can remember seeing were some tremor charts that had been smoothed or filtered so the trends are clearer – anyone know how you find those?

      1. The most interesting figure is that for conductivity (leidni, microSievert/cm). If there’s a sharp increase, then there’s every likelihood of fresh magma having reached the surface. However, with two recent ash-depositing eruptions, conductivity is high as it is (such as the 402 uS/cm at Múlakvisl), so it’s going to be hard to spot with any certainty for us rank amateurs.

  3. Sæll Jón. Vona ad thú talir íslensku 😉 Mig vantar enska ordid fyrir rafleidni (leidni) i sambandi vid aukid jardhitavatn i jökulám. Kannski thú getir hjálpad mér.

    1. I think that this word is electronic conductivity, but it might also be water conductivity. I am not fully sure on this word in English yet.

      I am born and raised in Iceland, so I speak Icelandic perfectly.

  5. All this activity at Mýrdallsjökull has become very interesting… and dangerous.
    I hope you guys in Iceland will avoid anywhere near the endangered areas – those floods can be fast, and voluminous.
    Everything concurs for this: a small eruption, the unusually high temperatures, the ash layer on the icecap, magma closer to surface…
    I don’t believe at the imminence of an eruption. At least not a huge one, as commented above. Maybe some other small events like these we are seeing.
    I am getting pretty sure that Lady K is preparing something big for the future.
    As for the flood: is the location where the flood has started in the field of view of the webcam? If so, we can see it!

  6. Yesterday I followed your blog-post, as I did July 19th. I remember the discusion about the steam formation at the glacier. Most of you concluded that it was just cloud formation. On July 19th the wind was from right to left on the Katla webcam.

    Yesterday I noticed that cloud formation occurred at the same three locations but the wind shifted from left to right. That cloud formation had a periodic nature. About every 3 minutes.

    Cloud formation will happen if there’s an increase in water concentration in the air or a decrease in air temperature. If there is water at slightly higher temperatures than the surrounding air you will observe cloud formation. Just look at a lake in the evening. The water is still warm and the air is cooling down. You will see fog formation.

    I think that the “steam columns” (July 19th) and the cloud formation yesterday are orriginating from water that is slightly warmer than the surrounding air. The location of one of the spots is (on the webcam) just above the minutes indication in the face of the glacier. I assume that there’s a waterfall with melting water from the glacier.

    Yesterday evening, arround 19.30, the cloud formation at this spot stopped

    1. @Richard:
      Thanks for your feedback.
      That should explain what we have been witnessing. 🙂

  7. Thursday
    21.07.2011 10:20:04 64.499 -17.522 5.0 km 2.3 99.0 13.8 km E of Hamarinn Hamarinn still active!

    1. I think earthquakes that appear in that area west of the caldera are normal and happen fairly often anyway.

  9. Jon, would you be able to photoshop in arrows pointing to the activity you speak about in the IMO charts. Sometimes I just don’t recognise what you’re referring to and it would be a great help if you have the time. 🙂

    2. I can try to do so. But I am no good with images program. But I use program called GIMP.

      But I might not always have the time to this if there is a lot going on. Like is the case with Katla volcano.

  10. Things are heating up with Katla………;)

    Sorry, couldn’t resist that one lol.

  12. Gygarholskot (gyg) SIL station is showing a quite rapid increase in tremor. It doesnt seem to be weather nor human made. What can be the cause of it?

    Gygarholskot is somewhat close to Hekla isn´t it?

      1. Ah I just noticed GYG is quite far from Hekla to the NNW.

        Dont know what is up there but there seems to be a repeating pattern of these spikes. Just that this time it was larger than usual. Maybe the river flowing close by experienced a smaller surge of meltwater or something.

        Never mind.. 😉

      2. Actually the closest I can see if Langjökull. But nonetheless the spike died down so Im just rambling here. 😉

  13. Thursday
    21.07.2011 13:16:54 63.637 -19.207 3.5 km 1.4 99.0 2.1 km E of Goðabunga It’s piking up?

  15. These earthquakes in Iceland usually come in “waves”, which leads me to suppose that the current localized activity in the above mentioned volcanoes is of tectonic origin, mere consequence of rifting.
    After all, we have seen it worse, haven’t we?

  16. i been reading this blog for a little over a year now. i have notice that everyone is very thankful for Jon time and his dedication to this blog (website) i think one way everyone could help him pay on some of his money problems is for him to have a one time fee of around or equal to a 1.00 us dollor. that would give him more time to spend on his blog and his book writing.

  17. All earthquakes has now been checked by IMO. Seems they want as accurate information as possible since they usually dont check every little tremor as they have done now.

    Something is brewing and I dont want to seem all doomy and gloomy but I would bet an e-beer that we will see an eruption within 2011. I would even go as far as to say within a few months. And that is really sticking my neck out. 😉

  18. @Lurking….

    If you are around and have all availible data would it be possible for you to make a plot of the recent months earthquakes beneath myrdalsjökull? Would be interesting to see if there is a hint of a magmachamber down there.

    Of course only if you have the time to do it. 🙂

    1. @Daniel:
      Actually, he doesn’t.
      He’s pleased to take his few leisure moments to provide us with such useful information .
      He plots stuff, as he says. But there’s much more to add to the competence he shows while doing them.
      We can only praise his constant willingness to help our greed for knowledge.
      Good ol’ Lurk… 🙂

  19. See? This one seems to have started the “wave”:
    4.7 2011/07/20 02:46:14 52.562 -31.767 10.5 NORTHERN MID-ATLANTIC RIDGE
    Then it goes further North to Reykjanes ridge, folows across the country up to Grimsey and then Kolbeinsy and possibly as far as Jan Mayen.
    Another example just happened:
    15:25:46 63.532 -23.859 1.1 km 2.4 63.85 5.3 km NNW of Eldeyjarboði

    1. Azores had a lot of erthquakes arownd M 3 in last weeks, specially in triple point region.

    2. It doesn’t work like that. This earthquake is also located on the African, South-America plate borders. Not the Europe, North-America plate borders.

      You can see this if you look at map of the plates.

    1. This cluster behaviour suggests that magma is moving and pushing up at those points. It might not erupt there right away. But it is hard to know what happens for sure when a eruption finally starts.

      This areas also appears to have increased hydrothermal activity due to the magma. This is also why there are glacier floods taking place at rather rapid rate at the moment. Even if they are just small ones.

    2. Torfajökull quakes are due to cooling magma (possibly chamber), or that’s what the literature says.

  21. Iceland is usually busy when I sleep so I miss things. Today I have a complicated evening meal to prepare after a busy day and what do I find? She has been busy again!
    I noticed that patten too Renato. It really looks like the Mid Atlantic ridge is having a little stretch doesn’t it?
    Many of the stations along the line west of Myrdalsjokull and Vatnsjokull are showing increased tremors. Nothing too marked. Could these be caused by increased flow from glaciers?
    Slysaalda, Skrokkalda in particular and this one is just wierd Vatnsfell http://hraun.vedur.is/ja/oroi/vat.gif

  22. Sometimes it’s good to go back to basics, and it’s always good to change one’s perspective. So don’t think I wanna give lessons with the following link, but just imagine on what we stand. The rocks beneath our feet are on the move, we’re all kind of surfers…
    http://www.ucmp.berkeley.edu/geology/anim1.html

  23. There never is any break this days.

    New harmonic tremor spike is currently taking place in Katla volcano. It was started with a ML0.8 earthquake at 16:56 UTC. I am going to post more information later on and earlier if this is something larger then small event.

    1. I was just about to ask if something was taking place in the area.
      All SIL stations around the volcano show a sharp, apparently enduring, spike.

    2. Looks to have dropped back to normal levels on the last update. Maybe the spikes were just the recent quakes and not a harmonic tremor spike?

    1. Kind of gives support to my expectation that we’re heading for a major eruption.

    1. Water levels? If there was a small flood after last nights small tremor spike we could expect to see the same again soon.

      2. “Múlakvísl, Léreftshöfuð; V414” might be the best one, if you look at the Graf and set it to 14 days you can see the huge spike in water levels from the glacial flood back between the 8th and 10th

      1. The “dashboard” is in a second monitor. The blog is in a web browser window in my primary monitor!

  26. Just missing the Hekla
    2011-07-21 17:15:49,7 63.970 -19.973 6.9 0.7 31.68 15.1 km Heklu V af
    only 31.8%

    1. There have been more earthquakes last few days west of Hekla. But I think they belong to the faults in South Iceland (South icelandic rift zone? don’t know the name anymore :P)

      Sander

      1. Yes they all belong to the SISZ, which means they are 100% tectonic in nature.

      2. Yes, but these tectonic forces propogate and eventually affect magma systems.

    1. Actually it looks more like the Eyjafjallajökull eruptions has coincided with the Katla eruptions since they are so many Katla events. The chance of an almost simultaneous (geological time speaking) eruption seems pretty big.

      And that would actually put to rest the theory that Katla always follows Eyjafjallajökull. Statistically speaking it would be really bad to base that assumption on so few events.

      I might be completely wrong but I think it looks like mere coincidence. But thats just me. 😉

      2. Fair point Daniel, but Eyja has preceded a Katla eruption the last three time Eyja set off. Historically, when Eyja erupted, it was follwed by another Katla eruption. And I didn’t say there would be almost similtanious eruptions, Katla has followed Eyja by a few months up to over a year. 🙂

        Twice is odd, three is bordering a coincedence into a pattern, and with a good chance Katla could erupt in months or some time to come, it would be an emerging pattern for sure. 🙂

      3. Don’t uh… fall victim to the human tendency to find patterns in everything.

        With the relatively high frequency of Katla eruptions, it is pretty likely that anytime Eyjafjallajökull erupts, Katla has either just had or is well into getting ready to erupt.

        http://i51.tinypic.com/abijj7.png

      4. Oh… an a caveate, both the normal and poisson distribution are crap for predicting when it will occur.

      6. I’m not falling victim to anything. I was saying what history shows about Eyja and Katla volcano, and it’s looking possible that history repeats itself. 4 times…..that’s a undeniable pattern.

      7. Wasn’t directed specifically at you. You happened to have the lead post on this particular topic and made the logical place to tag ancillary information.

        However, I would remind everyone here that all people are pattern recognition machines. It’s what allowed us to make it this far. It’s also something that occasionally makes us see patterns where there aren’t any.

        Statistically, it would be very unwise (foolhardy) to make a overall assumption about the eruptive patterns of Eyj and Katla based on such sparse information.

        Is there a possibility that the two affect each other? Yes. Geophysicists have busted their collective hump trying to identify that connection, or piping. So far, nothing definitive. Just hints. Even in my plots of every flipping quake that I can find in the SIL lists, I can’t come up with more than a hint.

      8. “There are tens of volcanoes all over the world that erupt within 18 months of an eruption of Etna. This is proof that all the world’s volcanoes are interconnected and controlled by Etna by some mechanism not yet understood by science.”

        People are free to believe what they wish, but more often than not, their beliefs say more about the minds of the believers than about the real world around them. Coincidence is not correlation, correlation is not causation.

      9. You know why it’s Etna that is used as a reference? It erupts so frequently that you’re bound to find your wished/favourite set of volcanoes erupting at least once within X months after Etna!

  29. Arrived this evening to see Iceland dotted with quakes! Wow! One thing I’ve looked for is a map / key for the seismic stations (the black triangles). The tremor chart has tiny orange spots that hardly work, the quake maps black pyramids. But I’d love to know which station produces which chart at a glance! If anyone has a web url I’d love to know. Thank you! Hope you got my donation, Jon.

  30. I believe when Katla went off in 1823 she set EJ off again, that is why the EJ eruption is 1821-3. Whether this news is science or 1820s press based I don’t know.

  31. Has there been a new Jökulhlaup i Mulakvisi? Looks like temperature, conductivity and water mass raised once more…

  32. Thursday
    21.07.2011 18:52:12 63.668 -19.160 3.5 km 1.7 90.03 5.4 km NE of Goðabunga

  33. Its interesting to see the migration of the quakes inside the caldera. At first they were SW to NE. Now they are SE to NW forming a cross now. Along with this is the cluster Jon mentioned at the SE rim of the glacier and now the new flooding. I’ll draw a simple hunch from this: the magma filled up a weakness to the point it could and encountered resistance and is now exploiting another one. Eventually, with all the changes taking place, at some point when there is a new wave from deeper underneath, there will be no where else to go but UP. This leads me to wonder if the eruption will be over a wide area and quite large. Of course, I could be entirely naive’ and mistaken.

    2. I like the way you explain the idea. Dopamine makes me see a simple logic behind it. I like simple things, or at least simple versions of what of course can be analyzed to an incredible, unlimited complexity if You break it down to molecular interactions.

    3. Looking back over the past year and a half, there are four areas of activity inside the “caldera”, cruciform as you point out, three in the northern part and one in the southern. (Godabunga is a fifth but it lies outside and is not part of the Katla volcanic system.) Activity is certainly up, but as Jón points out, it’s hydrothermal in nature even if the ultimate cause is rising magma deep below the volcano. To judge by the level of activity, the amount of magma involved is substantial, albeit not very great. Yet.

      According to the IMO seismologist responsible for earthquake interpretation, after you remove tectonic quakes, anything more shallow than 4½ km is hydrothermal in origin. If you look at the table, you’ll see that very few quakes are deeper than this.

      The signs to look for, as I understand it, is deep quakes (~20 km) signalling the rise of magma from the mantle. This will be followed by “rapid” inflation over the hole area as the magma rises and the quakes get shallower. In the case of Eyjafjallajökull, the area of uplift had a radius of ~25 km but the maximum value of the inflation was no more than some 7 cm just prior to the eruption.

      When Katla shows these two signs; deep and rising earthquakes accompanied by rapid inflation of the whole edifice, then we may assume that an eruption may be imminent (timescale; months to a few years). As things stand, the next eruption could be decades away unless there is a substantial intrusion of fresh, hot basaltic magma into the magma chamber, in which case there could be as little as days or even less between the beginning of such an intrusion and the ensuing eruption.

      1. Great reasoning here.
        So the attack of the “killer earthworms” is postponed, since the worms are still crawling deep beneath the surface.
        Thanks, Henrik.

      2. Well, it depends on the type of magma. Assuming Eyjaföll (the volcano under the Eyjafjallajökull glacier) and Katla share a common magma source with similar magma types erupting, yes, you might be right. But if I have understood it correctly, Katla and Eyjafjöll have slightly different magma types. And this difference breaks IMHO this reasoning.

        Additionally, Katla’s magma chamber is something like 2-3 km below sea level. Accounting for Katla’s height, I’d restate that anything above 3-4 km depth is hydrothermal (excluding magma and dike intrusions).

        Carl on Müsli had a theory about the factors behind Katla’s explosive nature of erupting. I kind of believe it, as Katla is situated in an area full of cracks. So, we may never see a proper inflation period identical to that of Eyjafjöll. I believe, Katla is already inflating, but it can not be seen clearly by GPS measurements. Maybe with radar and/or tilt measurements, but not clearly with GPS.

      1. If you remove those spikes from the recent earthquakes it looks pretty normal to me.

  35. Do Katla & Torfajökull share their magma source?? Or connected in any other way. I ask because the activity seems to be increasing lately as it has been with katla, is this merely a coincidence or could there be more to it???

    1. Apparently there is no connection between Katla and Torfajokull. But, in Iceland the activity of one volcano can trigger another. For instance, in 1477, there was a large eruption in Bardarbunga which happened to its SW, and it trigger the last eruption at Torfajokull. However, the fissure systems of Katla seems to run parallel to Torfajokull and so there might be no link between both. Some scientists have also noted some activity happening in Torfajokull before Hekla eruptions. I really don’t know.

  36. So does this mean that Katla is getting closer to erupting? Or does nobody know yet? Or… Am I being a bit naive? 😀

    1. Katla is always getting closer to the next inevitable eruption. It has been since 1918. 🙂

    2. If I stare hard enough at the web cam, it might blow? I can’t stop watching!!

  37. Remember a volcano has a sense of humor…if you watch it too close it will wait for you to go sleep! We’ll wake you if that happens. Renee

    1. The bubbles in Katla (kettle) are starting going upwards. Soon, the water (magma) is going to boil (to surface)

  39. Nice technique. I’ll try that with my old car. If it blows my insurance may pay me a new one…
    Sorry, I just can’t resist the temptation to make a bad joke… Everyone has it’s problem…

  41. Its funny how the blog has changed so much since Katla started rumbling. It was pretty quiet here before with a few people posting mostly factual content. Now that a large crowd has gathered, yet Katla activity has ebbed and flowed, the mileu seems bored.

    Thereby, I have an idea to perk things up. Lets start a gambling pool and start laying odds on Katla as to when, how, how big, how long, etc etc. The winner will gain widespread notariety and given a special title as the Blogs Official Soothsayer.

    I nominate Lurking to develop a grid.

      1. I don’t think the VEI scale takes into account lava flows, just the tephra (ash). A volcano can be VEI 1 and still erupt several Km3 of lava.

      2. Really? I was always under the impression that the things included in the VEI scale included everything a volcano would throw out, including ash, lava, and miscellaneous pyroclasts. I suppose gases would have to be excluded though, because they have a disproportionately large volume, so that immediately flaws my argument. Hmm. I’m not sure.

      1. Only ever made a bet once and the greyhound decided to stop and relieve itself!
        I tell a lie! I actually do buy the odd lottery ticket 🙂

    4. Wow, some of these predictions are rather depressing! VEI-6 indeed! My metaphorical money would be on a VEI-5 eruption starting in early to mid November and going on until around Christmas, resulting in Europe panicking and shutting airspace for a few days to a week around the tenth of December, which will turn out to be longer than technically necessary. Just because that’s how Europe works.

      1. Date range? No, just the actual date, otherwise, I could give a date range of 2 years.

      2. Ok, meant it like that:

        VEI 6: Starting September 2, 2011- ending around October 16, 2011.

    6. VEI 3 or 4, starting on Saturday 20 August 2011.

      I know this for a fact as I have a family party booked in for then, and Grimsvotn erupted while I was away at the previous family party. Now that’s REAL scientific reasoning in action! 😉

      By the way, is anyone writing all of these down?

  42. At about 20:26 UTC on Jon’s Hekla helicorder an earthquake larger than usual can be seen. It hasn’t been located by IMO yet, however (or maybe it’s not an earthquake?).

    1. Thursday
      21.07.2011 20:25:50 63.581 -21.268 6.3 km 2.3 90.09 31.1 km S of Þorlákshöfn

      2. Its on the tab labelled “Reykjanes peninsula”, it’s offshore so that’s why you probably missed it 🙂

  43. Hi everyone

    Can I throw a spanner in the works?

    When these small earth tremors started on Katla – just a few months after Eyjafjallajökull went quiet – all the tremors on Katla started under the north western quadrant of the Myrdalsjökull icecap. Over the months the tremors moved south-east until now they are under the caldera of Katla itself.

    In recent days I have seen those tremors start to move back towards the north west. Last week the tremors were in the south east of the caldera, now the are moving into the north-west

    http://en.vedur.is/earthquakes-and-volcanism/earthquakes/myrdalsjokull/

    Could it be that the magma intrusion rose up from under the north-west of the icecap; moved south-east; caused the flood and some ice-cauldrons to open in the caldera, but is now retreating away from the caldera and back up to the north-west?

  44. Hi everyone

    Can I throw a spanner in the works?

    When these small earth tremors started on Katla – just a few months after Eyjafjallajökull went quiet – all the tremors on Katla started under the north western quadrant of the Myrdalsjökull icecap.

    Over the months the tremors slowly moved south-east until now they are under the caldera of Katla itself.

    In recent days I have seen those tremors start to move back towards the north west. Last week the tremors were in the south east of the caldera, now the are moving into the north-west

    http://en.vedur.is/earthquakes-and-volcanism/earthquakes/myrdalsjokull/

    Could it be that the magma intrusion rose up from under the north-west of the icecap; moved south-east; caused the flood and some ice-cauldrons to open in the caldera, but is now retreating away from the caldera and back up to the north-west?

    1. I posted a similiar comment today and my hunch is that we are seeing continued magmatic pressure moving from under the crust and as this has worked its way up it, it exloited the weakness in the caldera where it blew in 1918 and once it did all it could there, the continued pressure moved over to the weakness in the NW rim.

  46. Just in case Clive didn’t see my reply and for others who want to see the SIL stations named. Try this link for the tremor map. For some reason the orange squares all work on this one and the names all appear! Well it always works for me!
    http://hraun.vedur.is/ja/oroi/index.html

    1. Diana – thank you SO much! My version of this chart had only half the squares working. And I could not track this version. That is of great help and, again thank you!

  47. Check skr think there’s a tremor starting or it might just indicate the earthquake that just happened there.

  50. Katla VEI5 on 7/9/11 – 10/10/11
    Hekla VEI3 on 28/10/11 – 9/12/11
    Bardabunga VEI7 on 2/1/12 – 5/4/12
    😀 Like the lottery I’ve based it on birthdays. As good away as any. Hopefully, I will not be the winner.

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