Posted on by Jón Frímann

Earthquake close to Hekla volcano. A earthquake swarm in Katla volcano

This has been a busy weekend in earthquakes, more then I was expecting. Here is a minor write up on the activity so far.

Hekla volcano:

A ML2.4 earthquake did happen close to Hekla volcano at 07:30 UTC. Depth of this earthquake was 3.7 km. The earthquake did happen on earthquake fault line that was created in a large earthquake in the year 1912. This fault line has been known since then and is well documented.


The SISZ earthquake this morning. This picture is released under Creative Common Licence. See Licence web page for more details.

Katla volcano:

Two new earthquake swarms took place in Katla volcano today. This earthquake started around 09:30 UTC this morning. Most of the earthquakes where smaller then ML1.0 in size. The depth was around 5.5 km on average. The largest earthquake was ML2.3 in size, with the depth of 5.5 km. That earthquake swarm was in Goðabunga area of Mýrdalsjökull glacier (Katla volcano). But here was also a minor earthquake swarm inside Katla volcano caldera. But in that earthquake swarm the earthquakes there where even smaller, most of those earthquake didn’t reach the size ML1.0. The earthquake swarm in Goðabunga area in Katla volcano might be due to dike intrusion in that area. I do not know if this might be something else. But given the data, this is the most likely the reason for this earthquake swarm in this area. The earthquake swarm did stop at 12:47 UTC. After that everything has been quiet so far.

Few earthquakes also did happen SE part of the Katla volcano caldera. But there have been earthquakes in this area since July. But this activity did start soon after the glacier flood from Mýrdalsjökull glacier.


Earthquake activity in Katla volcano. Copyright of this picture belongs to Icelandic Met Office.

All the earthquake swarms of today in Katla volcano, also the single earthquake close to Hekla volcano.

Icelandic news about this activity.

Mikið um smáskjálfta nærri Mýrdalsjökli (Vísir.is)
Jörð skelfur nálægt Hellu (Rúv.is)

Other: Short announcement. I have finally figured out how I am going to have my writing schedule. But my working period is going to be from 1. September to 1. June every year. This also means more activity on this blog and my other (Icelandic) blogs. During the summer time there is going to be reduced activity on all my blogs. But if something happens during the summer in earthquakes and volcanoes. I am going to write about it anyway or soon as I can do so.

Also note that I have started school to finish basic in electronic (house electronics and other basics in electronics). So I am busy during the day (most days). So my response might be slower then normal if anything happens in Iceland with earthquakes or volcano activity.

Other #2: I am having minor issues with uploading the gif images from my earthquake computer at the moment. So that is currently being done by the remote geophone computers at the moment. Because of this, there is no red colour if a large earthquakes happens in Iceland or close to a geophone station that I have up and running.

106 Replies to “Earthquake close to Hekla volcano. A earthquake swarm in Katla volcano”

  1. Following this blog for long but not posted before, nice blog anyway.

    After I readed this blogpost, I was looking on the webcam and there is smoke coming out of the katla volcano?

    http://www.ruv.is/katla

      1. That was not much clouds compared to the clouds forming over Hekla. This is nothing more than humid warm air coming up from the ocean and as it is pushed up and over the mountain (Hekla) and glacier (Katla) it cools into fog that forms the clouds. Normal meterology.

  7. Let me remind everyone who wishes Katla to erupt… There was only 4 earthquakes larger than 1 in this minimal swarm. It was not the start of an eruption, it was as Jón said, probably a small dyke intrusion into the Godabunga cryptodome.
    No eruption, no smoke, no crater, just a small quake-swarm.

    To put it another way. The combined energy release in this quake swarm was exactly 1/32 out of a normal swedish mining-blast… Do not get to exited untill you see hundreds of quakes above 2M pumping per day and going on for weeks… That is what happened before Eyjafjallajökull erupted, and I believe that is what is going to happen if Katla erupts. So we are far away still…

    1. I don’t wish that Katla erupts. Or only in the sense that I would feel safer after it does. So I wish for the smallest eruption possible. And people wishing for something big are wishing bad consequences for people living in Iceland!!

      1. I know you do not wish that. I should more have said those who are overly exited by Katlas reputation or something. But you know what I mean 🙂
        I would though rather see a big Katla, than a small Hengill due to the closeness to people.

      2. Thank you, Irpsit, for expressing my feelings so well. I have been reading this blog for over a year, not just because I am interested in learning about volcanoes, but also because I am fascinated by Iceland and its people.

        Those wishing for a major eruption of one of Iceland’s big volcanoes are wishing for an event that could bring harm or disruption to the lives of many people. I agree that it will exciting when Katla or Hekla or ???fjall erupts, but the only real good will be that it will relieve the built-up pressure, and lessen the chances of a more dangerous eruption in the future.

        And please don’t forget the sheep, Katla-cam watchers! Almost 80% of Iceland’s sheep died following the Laki eruptions of 1783-84. 🙁

      4. Evil, zombie-like? What have you done to the sheep to provoke such behavior? 🙂

      5. Nothing, they are evil zombies running after my ass…

        That is life, you wish for women running after your ass, instead you get horned woolly monsters hitting on your ass…
        😉

      6. But speaking in a Icelandic way, there is no point wishing or not wishing for volcanic eruptions, large or small. They would occur, small and large ones, always, that is just the way nature is. We, humans just have to adapt, and if we can predict, to mitigate damage and harm, then it is very very good. And I think this is the work that this blog is doing.

      7. Irpsit, now you got deep on us…
        Transfered into swedish that would be…

        Shit will happen, so build a toilett and start a comité on public sanitation issues in relation to fans.

  8. Volcanoes do not start eruptions by steaming, they only steam after eruptions. And this is even more true when a volcano is burried under 500 meters of thick ice such is Katla. There is no way steam could escape from the heated soil under that thick ice.

    Please, stop saying that this volcano is steaming. They are not. Often clouds over these glaciated volcanoes resemble smoke (and other weird shapes) but it is NOT! Its ridicule when people scream “hey Katla is steaming!” when it is not.

    You can only see steaming in the webcam of Eyjafjallajokull, and that is only sometimes (when wind is favorable).

    1. Some volcanoes do steam before they erupt. Look at Mount St. Helens just before it blew it’s top in 1980. It had some steam blasts before the main event.

      2. Opps, that’s my bad. Like I said before, I’m no expert and I wasn’t around back then. So I would not have known. Apologies.

      3. Speaking in a very easy way: volcanoes always start violently, not with soft venting of steam, but rather with explosions. Yes, sometimes they start with minor eruptions and then get stronger to large eruptions, like Mt St Helens or like Eyjafjallajokull, which started with some explosions but small and fountains of lava, and then puff… big eruption.
        Katla might start smaller also, but that is only if the eruption starts outside the glacier which is unlikely. The probable start for Katla is going to be a very explosive start (due to the glacier). The scale of “how big” and “when” are the two biggest questions.

      4. Katla is quite a different type of Volcano from Mount St Helens. For a start it has 200 – 300 meters of ice on top of it!.
        This volcano will not steam . I suggest you read this paper that describes what is under the icecap.
        Irpsit & Jon both live in Iceland and are extremely well informed. I suggest this as an good start to the structure of Katla and the surrounding area.
        http://www.raunvis.hi.is/~mtg/pdf/Jokull49_HBetal_Myrdalsjokull.pdf

    1. No. Geldingará (farm) is in Leirársveit – i.e. north of Akranes, west of Hvalfjörður (north of Reykjavík), i.e. nowhere near a significant Hydro-electric dam lake. BTW, I mentioned filling of lagoon´s as one cause for increase in strain. This usually happens from spring to autumn, mostly, depending on melt in higher areas.

      As a320er says, volcanoes do steam, both before and after eruptions start. The Eyjo´s first plume´s was actually quite white, then some ash appeared, yet it was basically white (seen from Hvolsvöllur). Probably only dark towards the bottom but on first day (April 14th, 2010) much was obscured by ordinary lower clouds, and only higher plume seen occationally. Only in later eruption period it turned dark (less water content, I presume). I think some photos were taken, some are on Flickr.com

      2. Yes, ok, wrong name, found it (again) now, sorry. The lake to the south is indeed a dam lake and there also is new Hydro station tunnels beeing built at Budarháls, maybe 10 km from this strain station, blasts there appeared on EQ carts last autumn.

      3. but there are errors on this chart!!!! Geldingará is in wrong place, should be just below word “Stöðvar” – So is Geldingaá also wrong. Must check ….

      4. but there are errors on this chart!!!! Gygjarhólskot is in wrong place, should be just below word “Stöðvar” – So is Geldingaá also wrong – seems beeing in middle of no-where. Must check ….

        (disregard my post below)

      5. Ah! But the important thing is that…. these dams close to Geldingaá, are just west of the area where large fissures happened from Bardarbunga like the Veidivotn. So, if magma is pushing up, then you might detect something at Geldingaá. I have no idea if the dam would actually worsen the situation. A part of the Bardarbunga fissure is under Vatnajokull, there eruptions are explosive and releasing huge amounts of ash, outside they release huge amounts of lava. So, the dam would probably add some minor explosive component to a future big lava fissure eruption. But that disaster would be really big for Iceland.

      6. Thank you for telling me that it is close to the Dead zone. It can explain a few things that I have noticed the last few days. Minute readings and quakes that are only picked up by one SIL and so on… Hm… I hate that it is no SIL in the middle of the dead zone.

      1. Thank you, that kind of made things much clearer for me. Although these are small powerplants they could probably influence a strainmeter during large changes in waterlevel.

    3. Eyjafjallajokull initial plume might have been white, but it was an explosive and tall plume, not just some steam. It was due to the contact of magma and water/ice causing explosive behavior. It was a fast moving and explosive plume. This is not a peaceful puff of steam that sometimes people think they see in webcams. No Icelandic volcano is going to start an eruption by that.

      When magma reaches surface it has to break rock, water and ice, and that causes explosive behavior. The least that can happen are some earthquakes followed by lava fountains. But that also does not start with steam. But it can start with the release of some (mostly invisible) gas before the eruption (magma degasing).

      1. Actually there is a special case concerning large earthquakes and steamy volcanos squirting about.
        After the 2000 Sprungur quake (mega-scale for Iceland 5+ something) the Volcano of Geysir started to have more frequent and voluminous ejecta being thrown out of the Geysir geysir. And if the Geysir isn’t pouring pure steam then I don’t know what is… 🙂

        I know, special case and there was no eruption. But, my point is that a large quake can change the pattern of a volcano so that its thermohydrodynamics is changed. And with a weirdly bad luck bordering on the impossible you could have small steamy puffs, and then an eruption. I know, marginal possibility-case.

  10. Hi,

    Could any explain a vulcano newbie what a dike/dyke intrusion is ?

    Thanks :O)

    2. This diagram may help explain some of the terms you will see on this Blog.

      http://www.sciencephoto.com/media/167497/view

      A dike intrusion is where rising magma finds it’s way along cracks called faults . Below a volcano there is a Magma chamber and pressure from this or from an earthquake forces magma upwards or sideways depending on the fault.

  11. The Other Lurker and Yet Another Lurker, I am having a mental breakdown from your names. Who of you two are the female icelandic person I e-mailed with before?

  13. In order to keep Carls mental state intact – and helping others perhaps – will abandon previous username, how about becoming “islander”? Hope this has not been used on this blog before.

    1. Sorry, it was not my intention to force anyone to change their name, it was just that I all of a sudden got unsure of whom I had been talking to when as I notied that it was 2 of you all of sudden 😉
      Islander sounds romantically piratic somehow 🙂

      1. heh I always wondered why there were so many loud mouth Lurkers here. I thought Lurkers were by definition silent. Might be causation there making them all speak.

      2. Yes, indeed, mosty silent and lurking in the background, only EQs and eruptions do make us speak.

    1. Actually I like the names lurkers. It seems funny 🙂 and quite good for a volcanism blog

  15. And while I am at it and talking about pirates, Iceland and other things… I got to think about my favourit line in a movie… “Þungur hnífur”.
    For those not of Icelandic origin I highly recommend Hrafn Gunnlaugssons movie When the Raven Flies “Hrafninn flýgur”. A must for any Icelandophiliac.

    1. Icelandophiliac or Icelandophile?

      Phile: Loving and friendly
      Philiac: An abnormal attraction to something

      Well either one could apply to us lot, I suppose! 😉

      4. There are so many possible answers to that, involving tremors, eruptions and making the earth move. But none of them are suitable for this blog, or perhaps even a first date, so we shall leave that unanswered!

  16. Terrible writer and director, sorry. No wondering Vikings turn about in their graves – their “disturbance” often shows up on EQ plots – mostly around Eyjo and Vik (where the film was shot).

    1. Nah, the epos is quite comparable to Leones rendition, but not of course Kurosawas.
      I know that Hrafn never became a prophet on Iceland but here he was one of the more iconic movie-makers of the late 80 early 90s.
      Many Swedes know the lines from the Þungur hnífur (at least if they are my age) scene by heart.
      On the other hand, I fall asleep as soon as someone mentions Ingmar Bergmans over-rated movies.

      So, I sincerely recomend it to all non-Icelanders 😉

  17. Can someone explain me what kind of tectonic movement actually exist in both SISZ and Tjornes fracture zone. I know that these areas are much more prone to big earthquakes and less volcanism, why that is so? And why do these areas occur in Iceland and there is not a clear continuity between the eastern and western rifts? And why we actually see a continuity of parallel rifting and volcanism between both zones, further north, in Hofsjokull? I guess this last example was because of the hot spot movement there. But if the hot spot would be moving, that would explain the more active eastern rifts, but then, why do we have so active volcanoes south and far away from the hot spot, like Hekla and Katla, at the end of the eastern rift? This has always been intriguing for me. Actually the entire zone between the fissures in Laki, Eldgjá, then the two volcanoes Hekla and Katla, and then the no-volcano SISZ.

    1. Irpsit:
      If you ever get a good answer for those questions, email me the books. I think you just formulated the end all of tectonic questioning for Iceland. It will take a few hundred years to answer it.
      You only forgot the Hengill tripple-junction and the heavy quakes at the Sprungur area. As far as I know that is the only area with 5+ quakes in Iceland. But I might be wrong.

      1. Carl there are large quake in other areas. Dalvik area has history of large quakes, about 1934 (Dalvíkurskjálftinn) that damaged or collapsed houses. And there is no real “hotspot” under Iceland (not similar to other known hotspots, nor is there traces of its movement), only broken pieces of very ancient crust from very old times (that probably explanis diversity of them lavas coming up). A good reference was posted by Jón a couple of blogs in the past, explaning this (it is in Jons replay to Carls on “transient” theory).

      2. Thank you for the for me unknown area of large quakes.

        I have to go and check back, but it is a bit daring to remove the “hotspot” theory from the basic understanding of Icelandic volcanism.
        It is after all a basic tenement and would then require a lot of redefinition of the volcanic progression of Iceland, and before Iceland in Greenland. Also it would make it a bit odd that Iceland is lifted up 45 metres compared to earth average.
        I think one should think things through mightily before saying that the emperor is naked. You need a bit of proof before doing it at least.
        The heavy fractioning of Icelandic crust is not problematic.
        As far as I have noticed you can say 2 things about the icelandic hotspot. 1, it is not behaving in the same way as for instance the Hawaiian (no shit, Iceland is by far more complicated), but it is behaving like the Azorian. 2, it’s movement is heavily debated. Some sources says that it has moved from Greenland and onwards, other that it is moving more erraticaly but latest from Langjökull via Hofsjökull to the current location close to Bardarbunga. I would guess that if you have access to a large inter-gravitometric observatory in geostationary or rapid orbit you could easily A) Determinate the existance of any hotspot (standard modell or not), and B) determine it’s trajectory withing about 4 to 5 years…
        Ah, forgot that they had made a gravimetric-image of earth showing where it was… But for funding reasons (NASA, not Iceland) stopped plotting the shifts in gravity.
        It’s to late too look for the link of the gravimetric-image, I posted it somewhere in January I think. Look it up and enjoy the hotspot in the sun…

      4. Also Kopasker in the north had destructive earthquakes in the past, but I can’t remember if they were magnitude 5 or 6. I think both the Tjornes and SISZ are the places where magnitude 6 quakes occur.

      5. The hotspot is the accepted theory on volcanism in Iceland. But there is a group of people trying to disprove it.

        But they are not going anywhere with it, as the data seems to disagree with them in that matter.

      6. If the crust under Vatnajokull is really around 45km or so, then its a big anomaly. This abnormal crust thickness and intense volcanism could be explained by the hotspot, but it could be that the explanation is yet another unknown one. I think there is really some sort of “hotspot”.

        But yes, the hotspot seems to be very different from Hawaii.

  19. The Emperor is naked. Good thinking. More basic studies have to convince me.

    I said no real “hotspot”, meaning it likely is not that hot. One article posted in Jóns blog (about Geology of Iceland) suggests no more hotter than 100 C compared to the surrounding rock. Others speak of mantle plume and put up pictures. There are no clothes on them pictures, no temperature scale, no chemical or age profiles.

    Why do modern times (say last 10.000 years) see largest eruptions mostly come in areas of the thickest crust. Is Iceland not like a boat on the Ocean, and it leaks. It leakes because it has hit (older) rock.

    I think (I do not say I know) Icelands volcanology is much more different, more about chemistry (that I am very slack at) and much more about mechanics (continental drifting / tetonic movement + thermal energy transfer / possibly from magma pushing more or less sideways “into” and over trapped much older continental crust). Iceland has part of Greenland lodged in the east fjords (Granite). No one has mentioned what millions years accumulation of oil can me mixed into, if crust is pushed into or over it. There is slight traces of oil north- and north-east of Iceland. Why not under it too?

    But of course I can be wrong about all I have said.

    1. There is evidence that the Hotspot under Iceland is not like other known Mantle plume Hotspots. The chemistry doesn’t support it. This leads some to think that rather than having a deep origin, it has a more shallow source.

      With Icelands proven large thickness in the Vatnajökull area, others have leaned more towards a layered pancake like theory, with Iceland consisting of a segment of continental crust laying on top of a segment of oceanic crust. The extra thickness might account for the increased melt generation that feeds the area, along with the MAR. This would also account for the lower hotspot temperature since it would not be magma of a deep mantle plume.

      With the chaotic makeup of other micro plates (postulated Hreppar and Tröllaskagi) and micro-continent (Jan Mayen), and the severe twist and rotation of Iceland in it’s formation, the pancake scenario has it’s merits.

      None of it proven, of course.

      I’ll shut up now. Wouldn’t want to be a “loud mouth” and offend anyone who is hyper-sensitive to conflicting opinion.

      2. When a tuna is tossed at you from out of nowhere its sort of hard to see the humor of it. I speak on behalf of all who lurk from behind the bushes or on the roof.

        True story; The general announcing circuit on a ship issues directives, warnings or notices to the entire crew. Such as” men working aloft” so that no one fires up a radar and knocks them off the yardarm. Import, the command had a raffle and the winner could make any announcement he wanted, as long as it was clean. The winner made this statement; “There are men lurking aloft, do not rotate, radiate, orenergize any electronic equipment while men are lurking aloft inboard USS (name withed).

        Funniest thing I had heard in a while.

      3. I do believe there is a hotspot, but since it is Iceland it is probably insanely more complicated than normal hotspots, but that is me guessing wildly.
        But the gravimetric map of Iceland showed Iceland to be almost uniformly lifted above earth normal with a slight biaz around MAR Tripple Junction and Bardarbunga. An idea (still guessing) is that the hotspot could be wider than any other “normal” hotspot, thusly having a lower temperature.

        About the temperature, remember that we are talking serious heat here, if it is “ONLY” a 100 degrees celcius higher than the surrounding rock, it is still ridiculously hot… 🙂

    2. Let me make this really simple.

      The established model says that there is a hot spot under Iceland. You are welcomed to disprove this by some real research. There are people doing that now. But the data does not seems to support there ideas so far.

      There is no oil in Iceland, even if there are remains of old continental crust below newer layers. The reason is simple. That old fragments of crust have been bent, boiled and fractured. Because of that any oil that might have been there is long, long gone.

      Icelanders oil dreams are just silly thing in my view.

      1. I’m not saying that its not a hotspot, just that it is most likely NOT a mantle plume.

        There is a difference ya know.

      2. “Oil dreams” maybe are unfounded for us, but as far as I know no actual explartory drilling has been done in areas like Húnaflói, where traces have been observed. I read some paper online on the Jan Mayen ridge and the mechanics, but I mentioned this as if Iceland is shifting sideways (moving and expanding) it may have expanded over some oil rich rock on edge the continental shelf, particularily to SE off east-fjords. I seem to remember oil has been found at 11 km dept (in Gulf of Mexico?) I however agree that likelyness of finding “rich” fields on land here is slim to none.

      3. There is no oil in Iceland. It is just too young. But most oil found on planet Earth is from 65 to 200 million years ago. Iceland is just around 20 million years old at the oldest points.

        Even the older crustal fragments are in place. They are both too small and have been hit by too high heat to managed to keep any oil in them. If it was there to start with. But that is a far from certain in terms of geology.

      4. Good explanation of the oil, I think I couldn’t have written it that short and yet informative.
        The problem with Icelands oil dreams is that you signed away your rights to the arctic in the Jan Mayen accord. Ie, Norway more or less stole your oil. But, in the long run you produce so much energy in other forms that it is possibly worth more if you would just start to export it in the form of electricity… But, that is not popular among the current Icelandic government to even talk about…

      5. Is it not taken that eastern Greenland and north west Scotland formed part of the same Tertiary volcanic province prior(ish) to the opening of part of the north Atlantic and that Iceland has formed along the spreading MAR. As the older ‘basement’ rocks of both nw Scotland and Greenland are of predominantly Pre-cambrian age, there can be no hydrocarbon resources in these. Nw Scotland does have rocks of Jurassic age that contain small amounts of oil shale as on Raasay and Isle of Skye and have been locally exploited on a very minor scale. It would need exceptional amounts of these to be present to produce a viable commercial deposit.

  20. I think a reasonable model for Iceland is:
    A hot spot under continental crust on a spreading center.

    The spreading center could initially separate the continental crust from Greenland. As the hot spot drifted beneath the continental crust, it caused weakness under this crust, which caused the spreading center to “jump” to the easiest place to break apart: the weak zone over the hot spot. This created the microplates and multiple rift zones under Iceland. Without the ridge, the hot spot would erode and incorporate the continental crust until it resulted in a Yellowstone-like large caldera forming eruption. But the spreading ridge relieves the pressure, in the form of volcanoes, before this can happen. Without the hot spot, the continental crust would have just stuck with one plate, and the midocean ridge would expand as they all do. Without the continental crust, you would have islands like the Galopagos.

    Of course, I have no geological degree or anything like that, so don’t take my post as anything more than semi-educated speculation.

  21. Semi-educated speculation is not necessarily worse than educated speculation. At the moment I cannot recall the papers concerned, but I have seen the Icelandic hotspot invoked as the culprit responsible for the Glencoe “supervolcano” in Scotland as well as having first formed Greenland and now moved over to form Iceland. If we move on to ill-informed speculation, hasn’t anyone connected the Icelandic hotspot to HAARP yet? 😉

  22. Just out of interest and maybe the information could start a new direction of thinking or put a piece in the Iceland jigsaw.
    Yesterday I was asking Volcanic related questions to the remote operated diving robot operator on the Ship Nautilus.
    http://www.nautiluslive.org/
    He responded to one about the MAR telling me this account.
    In 1978 he was a young scientist and was lucky enough to be present in a great new discovery.
    They were surveying the MAR and were taking temperatures of sediments on the folds each side of the ridge. They expected to find high temperatures when they came to the centre part of the ridge.
    The temperature at the centre was not as high as predicted . He said this confused everyone. The temperature had decreased on each side the further away from the centre they went, as they expected.
    So where was the missing Heat at the centre?
    A few hundred meters further along the ridge they found the first ever discovered black smoker on the MAR . Of course the temperature here was hot.
    They took further readings over a longer area and discovered that these Black smokers were the “Hot Spots” of the ridge and seemed to collect the heat energy from the areas along the ridge crest between the vents.

    My question to you is, ” If Black Smokers represents the collection of heat energy to one venting area, rather than a uniform release of heat energy along the crest ,up- welling, part of the MAR under the sea. Then what happens in Iceland similar on land? Are there places where the heat energy is released? Are these Geysirs?Are they Volcanos? or is the heat equal along the length with no steady release of this energy as in black Smokers?

    Maybe this is a dumb question and someone has answered this, or the answer is obvious.
    Has the drilling for hydrothermal energy used one of the on land “MAR hotspots”,( Not to be confused with the deep magma Icelandic Hotspot)

    1. I think I have answered myself here.
      http://en.wikipedia.org/wiki/Hydrothermal_vent
      However this does not explain the transfer of heat energy from either side of the smokers along the ridge. Does magmatically heated water “drain” toward the vents?
      What happens with geysers and hot spring areas? Do they take heat energy from the “Ridge Crest” either side of them?
      Sorry I am thinking “aloud” here.

      1. Diana B.
        Love your thinking aloud… *s*
        Can’t answer your questions alas, as they are similar to my own. But it is nice to see other people thoughts around.

      2. Thanks Starwoman.:)
        I tend to do all my “Thinks” early in the morning between coffees 1 & 2 and before husband, chores and normal activities makes my “Scientific” part of my brain close down!
        It sometimes emerges briefly during periods of automatic activities such as ironing, vacuuming and sitting watching yet another programme of car maintenance or restoration so beloved by my beloved!
        Sorry! I will get back on topic when I have finished cleaning my PC desk

  23. The latest swarm in Mýrdalsjökull. Its the West side of Katla, this could be the main body of Katla adjusting to last years Eyjafjallajökull eruption, slowly de-stressing.
    However somewhere in my mind a little voice says that this area could be Katlas version of Fimmvörðuháls, is there any logic in this?

    1. The latest swarm took place at Godabunga. It is thought that there is a shallow(ish) cryptodome at this location. One theory is even that it is not connected to Katla but rather a part of Eyjafjallajökull.

      it would be interesting to see if the ejecta from Eyjafjallajökull has the same composition as the older tephra ejected from Katla in 1918.

      And on the other hand if the cryptodome is indeed connected to Katla it is still an expression of the main magmachamber. So that would mean that the main body is further away from Eyjafjallajökull but has a westerly connection to godabunga.

      1. it would be interesting to see if the ejecta from Eyjafjallajökull has the same composition as the older tephra ejected from Katla in 1918.

        Basically is the godabunga magma the same as the Katla or the Eyjafjallajökull magma. By this I mean mineralcomposition, gascontent, and so forth…

      3. If I remember correctly they compared the tephra from 1918 with Eyja and got a blody nose. Same type but different but sufficiently different to not be related. That made the supposition that Godabunga is related to Eyja instead in an article published after 2010 eruption by Turkell (spelling… might be Turkleton as well…) But, the problem I have with this is that the cumulative seismic moment for Eyja and Godabunga is wildly different in its patterning, so different that I do not think they are related either. The cumulative seismic moment is mismatched for all 3 of them, so in my eyes there is probably no connection between Eyja, Goda and Katla. But… guessing here.
        Let me rephrase this, I would not be surprised if Godabunga will show itself to be separate volcano when it chooses to erupt in the not so distant future.

      1. Is it known if Katla is an explosion caldera c/f Santorini, or a collapsed chamber caldera ‘cos Haabunga could be different as well.

      2. I think it is considered to be a subsidation caldera, if it was an explosive caldera it would have been on the hugeish scale.
        If I understand it the general modell is that Iceland do not have enough energy to drive an explosive erupion on that scale. Be that as it may, I think at least Askja could go explosive instead of subsidising. The last time it had a mini-caldera event it was explosive, and I have not found any paper about the much larger caldera and how it formed. So, it might have been an explosive event.
        But, Katla is probably just subsidizing.

  25. I happen to run across a story about volcanic activity in West Bohemia in Czech with over 10,000 magma related quakes since 8/23 including some over 3.0.

    Is this bunk or just an under the radar small volcano?

    1. There has been quite a few earthquakes in Bohemia lately. I noticed them at the CSEM-network, with quite a few above 3.
      But… It is as far as I know just tectonic activity and not magmatic. But I might be wrong.

      1. I did not know that area had had some many earthquakes. They speak about magma movements in the article, are there GPS readings there going up?

        There is a small hot spot of volcanism well further west in Germany, I cannot imagine that its because of that, and sometimes in central Europa powerful earthquakes happen, like the one in Basel. Only a GPS measurement would clarify the question.

  26. Either Iceland is setting a new record in nothing happening, or something weird is afot.
    Nothing is tremoring, nothing is quaking, nothing straining, and nothing at all happens on Jóns Helicorders.
    Jón, have you adjusted the setting for Heklubyggd so it is lower?

    1. I guess we all know Irene is heading our way, but at the moment not even the vind is moving…. Called “the lull before the storm”. ((((Now something MUST START shaking, blowing or erupting…)))) Sorry for not commenting on all answers directed at me. Been busy.

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