Activity in Iceland’s Dead Zone

Photograph by Skúli Thor Magnusson. Stunning view of the Veidivötn Lakes.

The Dead Zone

In the area going from Vatnajökull down to Torfajökull and Myrdalsjökull there is normally almost no seismic activity. This has given the area the not so scientific name of the Dead Zone. It contains the fissure swarms of Bárdarbunga, Grimsvötn and Katla. Grimsvötns fissure swarm is called Laki and Katlas is called Éldgja.


Bárdarbungas fissure swarm is called Veidivötn, and has had the largest lava-floods on the planet in the last 10 000 years. The largest of those is called the Thjorsahraun putting out an estimated 20 cubic kilometers of lava.

Photograph by Örn Óskarsson. Anybody who wishes to rent a cabin?

Rifting Fissure Eruption

When Katla, Bardarbunga or Grimsvötn has a major and sudden influx of magma from the hotspot, and the fissure swarm of the volcano in question suffers a rifting of the Eastern Icelandic Seismic Zone opening it up. Then what happens is a VEI-6 eruption at the central volcano, and a minimum of 10 cubic kilometers of lava erupts down a minimum of 100km fissure. It is the most destructive type of eruption likely to happen in the northern hemisphere.

The reason of them being that problematic is that it at the same time it releases a lot of ash into the atmosphere, about 100 times the amount from Eyjafjallajökull and also the fissure releases a lot of sulphuric gasses. This phenomenon is called dry fog, and was reported in most of northern Europe and the USA during the eruption of Laki in 1783.

The Laki eruption is the most deadly in European modern history due to the famine that followed. 1783 is also known as the year without summer.

Dead Zone activity of today

Image by IMO. Look at the line running up from Torfajökull/Myrdalsjökull, that is Veidivötn.

During the last 12 hours a series of small (1 to 1,8M) earthquakes happened inside the Dead Zone. They trend from Torfajökulls Landmannalaugar up along the Veidivötn fissure towards Skrokkalda.

What is remarkable that this phenomenon has never been recorded before.

At the same time there where harmonic tremoring in the SIL-station of Skrokkalda, Vatnsfell and also Snaebyli, shown here is the activity at Vatnsfell.

Image by IMO. Vatnsfell SIL-station showing harmonic tremor.

There has also been activity at the Dyngjufjöll, the principal SIL-station of the Bárdarbunga volcanic complex.

And here is a webcam of sorts for the Veidivötn area:

Caveat for the press

Please dear all, it is still far from any possible eruption in the area. At most this is a signal of what can come, nothing more.


453 thoughts on “Activity in Iceland’s Dead Zone

  1. I’m not very good with the techno-thingies so the Youtube-embedding might get horked up!

    But here goes anyway; a rather cool video from the newest iteration of Douglas Adams’ Last Chance To See series (2009) where his buddy Mark Carwardine gets shagged by a rare parrot whilst Stephen Fry watches. Pure happiness 🙂

    • I love that clip Tor Thank You. As a biologist I immediately wonder why the parrot chose one man not the other. This Kakapo , like the Kiwi is a bird of new Zealand. The Kiwi has an excellent sense of smell as it smells out worms to feed on. It is of course flightless, living always on the ground. The kakapo also lives much of the time on the ground. I suggest it also has a keen sense of smell. Maybe the man’s aftershave aroused this parrot.
      Moral…….Gentlemen, be very careful which aftershave you use !

    • Tor. next time just copy the youtube link into the text, without any code or anything and it should turn into an embedded video by itself. 🙂

  2. Mizar, your CPMC is none other than the Iceland Hot Spot. If the Hot Spot burps a magma or energy bolus, you get these quakes all over the place courtesy of the MAR. But as Carl points out, we haven’t seen the propagation up one of Icelands infamous rifts before which makes the current episode unique. Is this fairly normal once you make an allowance for the fact that it’s only in the past 15-20 years there’s been a detection net in place capable of registering this and thus nothing to worry about? Is it the start of a magma infusion/intrusion into the fissure? If so, how long does this need to continue before there is reason to worry for, if not ourselves, our grandchildren or great-grandchildren? What ARE the signs to look for if a Laki-style eruption is imminent (imminent = over the next 25-75 years)?

    • Volcanoes are very difficult to predict.

      One thing I can tell you. There is a continuing rapid uplift in Skrokkalda and Hamarinn, for many years now. This is a sign that sooner or later there will be a Veidivotn style eruption.

      I think an eruption like this will occur within the next 80 years, as we will have a new peak in hotspot activity and in Vatnajokull.

      • And we should remember that Bárdarbunga has not had a decent eruption for a hundred years. And since it is sitting ontop of the center of the hotspot it has jolly well most likely had that inflation going for a hundred years. So there is a large likelihood that Bardarbunga sits on enough lava now to do something rather fresky.

          • That is a rather hypothetical issue realy, nobody so far proven that the hypothetical link exists. I would say we would need to see a lot of research on it to clarify the matter, and sadly that is rather hard as long as there is a glacier ontop.
            Personaly I think that if there is a link, it is not a permanent one. More like a temporary fissure opening from Grimsvötn into Bárdarbunga via Grimsvötn northern fissure swarm. There was also a rather conspicous trail between Hamarinn and Grimsvötn before and during the eruption of Grimsövtn 2011. That trail is actually a stronger link between Grimsvötn and Hamarinn, than has ever been seen between Hamarinn and Bárdarbunga. And saying that usually pisses people off.

            But, Bárdarbunga is the least known of Icelands large volcanoes. This due it never having erupted so that we can get data.

  3. Good morning everyone again. What a lovely start to the day. @ Lurking. Thiose plots will lead me to much rumination. I need time to study them. Thank you.
    I saw that line of quakes yesterday and knew they were something different, but I could only glimpse and then rush off to family matters.
    I am intrigued by them. thank you carl for this rapid post. thank you Lurking and Ursula and others for your inputs.
    It;s so easy to jump to conclusions and to worry It is good to remember that as henrilerevenant above says, monitoring is as yet a young science. It is good to accept that whatever happens we cannot stop it. It is good to remember volcanologists are working hard to understand and to be able to predict.
    It is good we can be here to discuss events, to argue and to share.
    It is bad that I have nearly run out of my favourite coffee and I need another cup, maybe husband will be happy to drink tea for a change!!! 😀 (I must be the only English woman who really HATES tea! )

    • As a sample what Diana said:

      Science 23 April 2010:
      Vol. 328 no. 5977 pp. 410-411
      DOI: 10.1126/science.328.5977.410
      •News of the Week

      Iceland Eruptions Fuel Interest in Volcanic Gas Monitoring

      Lucas Laursen*

      Icelandic researchers and civil protection officials are continually analyzing several streams of data to make educated guesses about the duration and size of the eruption on Eyjafjallajökull, the volcano that on Wednesday, 14 April, turned from a modest tourist attraction into a nightmare for airlines and passengers across Europe. Everyone wants to know if the volcano’s ash cloud, harmful to jet engines, is going away or will remain a threat. At a briefing here called on 19 April to share the latest observations, University of Iceland geophysicist Páll Einarsson summed up the frustrating conclusion: Despite all the data, “we are still looking for an answer.”

    • The magic of it all. No matter how much we now, there remains plenty of room for the unpredictable and surprises. Preparing the world for the very big events is just impossible, and they can strike tomorrow or in several hundreds of years. Difference between us and scaremongers? We don’t freak out because some things are out of our usual perception range and try to keep reflections rational. probalby why I hate them. Some of our interests are not that far apart, but they discredit my thinking on these things by their silly conclusions and you’re looked at like a fool when you dare speaking of potential global consequences of volcanism.
      Back to the classic Sunday family obligations (quite a stabilizing thing after all…)

  4. henrilerevenant, thanks for this answer, and quite interesting questions. And to be clear, I have no idea, and I think no other has a definite explanation of how everything is connected there . But i know the well proven theory of the geology of Iceland is well studied and accepted. As the CPMC only exist in my mind, and for me difficult to prove (how should I… 🙂 ) I still play around with those thoughts.

  5. When I first started following Iceland’s Volcanic history ,I found it difficult to comprehend the size of the various eruptions. I had no real concept of x number of cubic kms. or meters height.
    I found watching clips on you tube very useful. It helped to put events into perspective.
    Try watching this clip to show the expanse of lava flow from the Laki fissure. You can clearly see the fissure running into the distance.

    Then watch this. The music I turned off but the microlite gives a good idea of the scale of the volcanic cones and lava flows

    Then to give an idea of the depth of the lava flows listen to this, watch the short clip in the post below

      • This is part of the docu i linked ( German version).
        I was looking for it in english. As long as the comments in the background are all in english there should be an englisch version probably by the BBC but i could not find it.

        • I’ve been looking too. It’s from a BBC programme called “Killer Cloud” and is part of the Timewatch series. The BBC website search engine is not very good (to put it mildly). I can’t find the whole programme.

    • Diana, Its such as amazing video.
      Personally I haven’t been yet to Laki despite living in Iceland for 2 years.

      But I have been in Veidivotn and in Edlgjá, which are fissures even bigger but older (so less preserved)

      Well, Edlgjá is an astonishing very long (60-80km) canyon, which averages about 100 meter deep and 200 meters wide. A hike there you feel you are inside a huge canyon, with lots of craters at this bottom. Outside the canyon everything is black for hours driving.

      Veidivotn is like a long row of big craters, which are filled with lakes, and many volcanic cones also abound. The area there is desolate. And lava fields are huge.
      One lava field reaches 200km southwestwards. Can you imagine that?

      But you can see similar crater rows and fissure eruptions nearly everywhere in Iceland. They less famous fissures are often large with volumes of lava that approached those of Laki. You have at Hengill, Thingsvellir, around Langjokull, to the north…

        • Irpsit, thank you. Iceland is an amazing place especially for rock nutters like me . I think my husband would enjoy the 4 x 4 trucks more!!!
          I so want to go there. All I need is a lottery win and the OK from my doctors. I dread to think what my health insurance would cost me.
          Thank goodness for this blog and the magical ability to see things on line. I still marvel at the web cams. I make no apology for my naive enthusiasm.
          I have given instructions to my family if ever I have to be put in a home for what ever reason it MUST have internet connection and they MUST buy me a top of the range Laptop!!!!

  6. If the volcanology is a table with 3 legs:


    Should not be a great anomaly in the measurement of these gases before any such event as Laki?

    would be these gases the 1st signal?
    the trigger and the moment could be when more than one leg of this table are activted?
    At the same mode you can measure the duration of an storm depending of the time the weather was going worse before the storm… when longer time worsing before, longer the storm…
    could be used with eruptions?
    If it could be used then what parameter is the important for saying us the duration?
    since seismic activity was started?
    since gases abnomalies were started?
    or not chance with this?

    Are there links to graphics of diffuse emission of Co2 and diffuse emission of So2 at Iceland?
    Other links of gases measurements at real time from Iceland?

    Might we use seismics and gases datas previous to the eruption on Eyjafjallajökull 2010 to review about the duration and size of the eruption on Eyjafjallajökull?

    • Carlos, short answer no.
      The reason for this being that the runup action magmawise would be at the parent volcano. And there is no way to know if that will end up as a normal eruption, or a rifting fissure eruption.
      The rifting fissur eruption is tectonic, it is just a tectonic rifting that runs all the way into a magma reservoir, and just sucks it dry more or less. The size and duration of the rifting fissure eruption is set by many factors, the most important is if the magma reservoir is filled to the brim or not when the rifting occurs.

  7. Great plots GeoLurking. If I understand it correctly, there has not been any activity in the dead zone since 1862, unless it occurred “out of site” under Mýrdalsjökull or Vatnajökull.

    • Last activity in the dead zone was in 1783 in Laki (Grimsvotn), if I am not wrong.

      In 1862 there was a fissure eruption in Trollagigar (Bardarbunga), which I think it is to the north of Bardarbunga, so to the other side of the central volcano.

      In 1910 there was a small eruption close to Hamarinn, but the fissure was undeneath the glaciar, but quite close to where Veidivotn fissure starts.

      Veudivotn last erupted in 1477.

      • Karen, also the nice thing is that probably many eruptions in Bardarbunga are not recorded in historic accounts, as the place is remote and there was no one living there, and before 1950 people would only cross the area rarely on horses, in what would be a very long and dangerous trip.

        I want to go there this summer, and have a look at the volcano, and see if i can see some nice ash layers from past eruptions. But its a quite remote place.

          • The nice thing in Iceland is that there is so MUCH to study, so many volcanoes, and often in remote and difficult to go places. With so little people in Iceland (and still less scientists), most of Iceland is still poorly understood.

            This makes everything very exciting.
            I am particularly fascinated to know more about ancient eruptions north of Vatnajokull, and those north of Hengill, as they are not so much studied as the ones of Hekla or Katla

  8. To those with an interest on Laki, look at this top10 ranking of most lava volumes on eruptions of Iceland since the ice age, last 10.000 years. The ranking are just estimations of lava volumes, and some ancient eruptions might have been not recorded yet by scientists too.

    Laki seems to rank as 4th largest lava eruption since the ice age, and Eldgjá as 3rd.

    Carl’s favourite Theistareykjabunga could be 2nd or even the 1st because the volume could have been underestimated. The other huge one, 1st or 2nd is Þjórsárhraun eruption from Veidivotn, which left an unbelievable lava field more than 200km long from Bardarbunga to Selfoss.

    Other giants on this rank (and could even surpace Laki, if they were underrated) include Hengill in 8250 BC and some eruptions of Langjokull.

    – 6650 BC Bardarbunga/Veidivotn (Þjórsárhraun) 25 cu km lava
    – 9500 BC Theistareykjabunga 18 cu km lava
    1- 934 Eldgjá/Katla 18 cu km lava (+ 5 cu km ash)
    2- 1783 Laki/Grimsvotn 15 cu km lava
    – 5000 BC Bardarbunga 15 cu km lava
    – 8250 BC Hengill/Thingsvellir 11 cu km lava
    – 7550 BC Prestahnukur 11 cu km lava
    – 5850 BC Hveravellir 11 cu km lava
    – 9000 BC Brennisteinsfjöll 10 cu km lava
    3- 950 Hveravellir 9 cu km lava

    Carl: by the way, I was thinking, couldn’t be that Thingsvellir could be an ancient caldera of Hengill? That would make Iceland’s largest caldera.

    • Yes, that is probably the correct list, I do have one addendum to it. You have a large field running from Askja up to Svartarkót that I have not found a volume calculation for. But judging from the size it should be around position 5 – 10.

      In my mind lake Thingvellir looks a lot like an old caldera. And Hengills fissure runs right through the lake. So yes, I do think that, but it is not proven.

    • I did this based on Global Volcanism Program list, which as we knew is incomplete, and this is even more so, for Bardarbunga and Grimsvotn (and probably Askja too).

      I wouldn’t be surprised with many more 10 cu km lava eruptions missing on this list.

  9. Specially for Diana…
    As today you have a lovely sunday morning because you didn´t hear your husband clock in dolby sorround at 4 am…

    For a lovely afternoon…
    A video of an amateur “reefer” (owner of a reef tank) with NPS (non photosynthetic corals)

    Photosyntetic corals could be keept in reef aquariums when the tech of lightening and water filtration was enhanced but this kind Non photosyntetic corals must be feeded (phytoplancton-zooplancton) and a few years ago it was an event nor scientist nor amateurs are able to do until the researches and enhance with the feeding techniques and kind of foods…
    I hope you enjoy with this video, Diana.

    • Carlos ! Wow that is amazing. It must need much dedication and careful set up and maintenance to keep this tank healthy. Quite amazing. I shall have to go and find out more about how these polyps are fed. When I win the lottery I would have enough money to set one up 😀 But first my visit to Iceland :D.
      Yes it was good to sleep in until 6.00am :D.
      I have just finished much work in the garden. Cleaning out my potato planters redy for the early crop. pruning fruit bushes and erecting a climbing frame for my Kiwi fruit plant. best of all watching a family of Long tailed tits, unusual visitors to my garden.
      I nearly trod on my robin he was in such a hurry to get to the bugs disturbed by my moving old leaves and planters . Spring is making headway, but it is still cold.

    • Bookmarked! I think it would be really useful if you could, once you have some time, put up a page with your icelandic links, please. If you don’t know how to link it into the menu, I can do that, if you create the page first (as you did for Burfell BBQ). Pretty please? 😉

    • Ahh… the source of the oddly shaped boxes.

      Thanks! I wonders how they hell they came up with the demarcations that they did.

  10. OT – I like many types of music from Earth Wind and Fire (70s guy) to todays’ pop but have just re-discovered Sibelius and for the Finns out there ( Carl ?) I know this chap may be close to your heart. Finlandia – amazing big sound ! or Valse Triste or Karelia Suite. I used to listen when a teenager but my mum’s brother was killed during the war and this was his favourite music and so it was more or less banned. Any time it was played used to start my mum crying. So glad that I can now listen to it once again after all these years. Amazing stuff – must find a concert somewhere. Sorry to post OT but had to share this with someone ! Have a good day.

    • Nah, I am just a neighbour of Finland 🙂
      But I agree, Sibelius is lovely, and I would also like to point to Norways Grieg.

      • Good choice – listening to Morning from Peer Gynt just now. I have an empty house at the moment and trying to listen to something other than hip-hop or very loud rock which my daughters can belt out of different rooms.Thanks for the suggestion.

    • There are still people sorry to post off topic. Hasn’t this group got over that. We have even chicks (;-)) talking about knitting and tatting… Come on. Next to volcanoholism this has since long time become a platform for a decent bit of soul striptease among virtually nice people.
      We should set an ethic code for important phases: no knitting and Gripen talk if some fat fissure eruption really starts to happen. But in the waiting phase, how great to extend our general knowledge and learn about others passions. You never know where you find inspiration / muse.
      But that’s only my point of view.
      Nice pieces of music.

  11. Found the full version of ‘Timewatch: Killer Cloud’ in English. It’s about Laki and it’s effect on Iceland, Europe and particularly England. Well worth a watch.

    • YES Thanks Talla. This seems to be the original!
      And for ( i think) the very first time i find the german title better. Cause the english one harbors a little fear mongering. And the documentation is not fear mongering, it is just a statement of facts. People back then could not act as globally as we can now. SO2 clouds, fog and ash. Of course many thought all hell broke loose but could not make the connection with a volcanic eruption in Iceland.

      • Agree that the title is a bit Daily Mail, but the information is fascinating. I remember watching it when it was first shown and it made a big impression so I’m glad Diana found the first clip so I could track it down.

    • Three thumbs up.

      (Why the extra thumb? Because two are not enough. Grab a friends thumb if you don’t have enough)

    • Thank you – an interesting watch!

      (I also learned that I can watch youtube on our TV, so it was educational in more than one way!)

    • Very good and sober documentary, although a bit funner that they mention Heimaey as the last Icelandic eruption given the events of the last two years

      • It was actually produced before Eyjafjallajökull.
        But they missed these eruption anyhow.
        And no less than 3 Heklas…

  12. stain is visible at el Hierro now that the sun has moved. a little degassing in the last 45 min, over a pretty wide area.
    I wish they’d bolt down the pan cam a little better, it sways with every breeze 😦

    • 5th and 6th tremor of the day..
      19/02/2012 15:15:44 27.7131 -18.0755 11 1.5 4 SW FRONTERA.IHI
      19/02/2012 15:16:34 27.6640 -18.0989 9 0.8 4 SW EL PINAR.IHI

  13. This morning I was working my way through all these records, mainly to try to compare the seismicity of the areas around Hekla . I was wondering if there was any correlation to activity at the moment.
    I had to give it up as Husband awoke and needed to be fed and watered!
    We seem to have more activity at the moment than in the early months of years 2000 .
    To find the list of years click on the tab labelled Aðrar vikur (Other weeks )
    This week is week 07, so I clicked on the year 2000 and then week 07. (The month names to the right do not always match)
    Below each weekly map is a very nice description that could prove to be most useful.
    I am trying to think of a way to make easy comparisons of these maps. It would take some time and would best be done with overlays of some sort.
    Oh dear! Another thing for me to think about. Who said retirement is boring?
    Has anyone any ideas on this?

    • Yes, the run up to this Hekla event has both been longer, and contained more seismic events. One should though note that this probably would be withing statistic average if we had more statistics to go on.

      • I agree Carl. Considering there are no records that I can find prior to 1993 we are thinking very much in the dark.
        This is a good reason for people to not jump to hasty conclusions.
        I do believe that our comments and discussions here may be very useful to the next generation of Volcano addicts!!

        • Great work Diana.

          The other thing it would be so useful to have, would be measurements of sulphur and CO2 gas around Hekla. Though i live 50km away, I only go there about once a month or two (because of the current snowy roads). I am sure locals will feel the changes just before the eruption. But I have a solution… 😉

          Just before the 2000 eruption the peak was without snow (the eruption was in a February). Now Hekla is full of snow on its top, but still with some steam (which is normal). I use my binnoculars to check this. Nothing has changed yet.

          So i hope when I see something changing at its top, that I could infer another sign of eruption. Maybe its very foolish, but since I can have a distant look at Hekla every day (when weather allows), I might find something. The same goes for Hengill. It was steaming quite a lot last Friday but less on Saturday. I am sure they pumped more water last week.

    • Psst.. those are the maps generated from sveni listi. The source files are the same ones that I put my master file(s) together with. The thing has more that 270,000 quakes and is several megabytes, typically more than you would even attempt to digest with a spreadsheet. A full on database application is better suited, though I haven’t gotten around to setting it up in one.

      To give you an idea of just how much data it is, I’m running a quad core Phenom II system. I imported the quakes into DIVA GIS, and made a shape file. Doing a translation from lat-lon to Mercator projection took about 20 minutes.

      • <<<<<<< Gulps! Sheesh! I don't think I will try anything too much with my baby dinosaur Hal. I think he would possibly get indigestion and blow something inside!!!
        `Lol ! Lurking I think i will leave the graphics and stuff to you. Far too advanced for this old bird!

  14. About Eyjafjallajökull…

    By 26 February 2010 the Global Positioning System (GPS) equipment used by the Iceland Meteorological Office at Þorvaldseyri farm in the Eyjafjöll area (around 15 kilometres (9.3 mi) southeast of the location of the recent eruption[15]) had shown 3 centimetres of displacement of the local crust in a southward direction, of which a 1 centimetre displacement had taken place within four days. (See the GPS Time Series page of the Nordic Volcanological Center’s website for detailed information on the degree of movement detected in the Earth’s crust in the Eyjafjallajökull locality.)

    This unusual seismic activity along with the rapid movement of the Earth’s crust in the area gave geophysicists evidence that magma was flowing from underneath the crust into the magma chamber of the Eyjafjallajökull volcano and that pressure stemming from the process caused (in geophysical terms) the huge crustal displacement at Þorvaldseyri farm.[18] The seismic activity continued to increase and from 3 to 5 March, close to 3,000 earthquakes were measured having their epicentre at the volcano. Most of these were too small (magnitude 2) to be interpreted as precursors to an eruption, but some could be detected in nearby towns.[19]

    The most recent scientific observations are on the website of the Institute of Earth Sciences which details the current situation for the eruption in Eyjafjallajökull. The Nordic Volcanological Center also maintains an Eyjafjallajökull status page

    • At that time I was not following Icelandic situation at all.

      But if I, or any of you guys, were following this in early 2010, we would be suspecting something was about to happen in Eyjafjallajokull.

      Now we don’t have such clear sudden displacements, but we have some long term uplift in Hamarinn, Katla and Hekla. With Hekla we already know we cannot predict it well, but with the other two we should expect sudden uplift and earthquakes before an eruption.

  15. @ GeoLurking/Ursula/Karenz, and any other schpreadscheet gurus out there,
    I’ve a plot ready to post which may be of interest (especially for Judith and our Canarian friends) it’s nowt special really… But anyhoo,
    I’ve saved it as a chart in an Excel workbook… How do I save the image to post on Tinypic?

    • I save the worksheet as a PDF then convert to jpeg, & then upload to tinypics.

      Not tried it, but you may be able to copy the chart (click on it followed by “control c”) direct into photoshop (“control v” into a new file), then upload to tinypics.Just make sure that you have saved the spreadhseet before you try this.

      Good luck.

    • It’s really nuffink schpecial Judith, but thanks for the anticipation x
      I’ve learnt as much about information technology as I have about geology in the last few months 😉

      • Thanks Karenz x Second tip seemed to work…
        I’ve been ruminating on the “are the EQs getting shallower lately? Question”
        The plot? I think it may be an illustration of the 1st rule of statistics: 78.2% of statistics are made up on the spot!!!
        The graph shows all EQs (including tiddlers) from sometime in earlyish November until now (for some reason Excel reads dates in the format xx/xx/xxxx as garbage?) A total of 1500 EQs (about 10% of Canarian EQs since 19/07/2011)
        The plot does show a trend to shallower EQs.
        It shows that the recent concern about shallower EQs is not without foundation.
        But do please bear in mind that the data has been selected… Why the last 1500 EQs? Because that’s what my excel would (just about) drag and drop from the IGN catalogue.
        Interestingly that set of data illustrated what people have been saying…
        Why haven’t I showed all EQs since the beginning? Again excel limitations…
        So EQs have trended shallower lately, but overall they remain within the wad…

        The moral of the story? Just remember who’s doing the plot and with what particular set of data x

  16. Wow…. that is neat.

    I just noticed a number next to my name on the WordPress bar at the top (the one you get after you log in) it shows you the number of posts that you have made that have responses to them. Clicking on it shows you a link to the posts.

    That’s handy!

      • This does not seems to be Hekla (closer stations are quiet), but could be Vatnfjoll, which is another volcanic system to the south.

        I dont think it is Katla or Eyjafjallajokull either, as the tremor shows only in some of its stations to the north. Therefore, it can be also Tindfjallajokull or Torfajokull.

        But this does not show any signs of magmatic tremor. Maybe a small flood or avalanche caused by the recent rain of today?

  17. Avcan FB Comment By Avcan

    Sorry dont know how to post the graph but can be seen on the Avcan FB Page..

    Spectrogram of MACI processed by AVCAN with the data from the IRIS network with a sampling of 4000Hz frequency, where the two seismos produced yesterday in Tenerife, the first of these 3.3, to the right of the graph can be seen

    • As you can see, Antonio Manuel González Brito there were two events captured by MACI, another thing is that the second is not capture in other seismographs with the necessary scale and and therefore not be could triangular accurately to be included in the catalogue of the IGN. The second was to be a replica of the first and much less intense. Also shown in the seismogram which you can get with the GEE (Global Earthquake Explorer) programme. (JR)

  18. I wonder if those regular tremors at Slysaalda they everyone thought were related to Hamarinn are instead from magma moving into Veidivötn instead. Any thoughts on this?

    Also does anyone know whether the fissure swarm of Bardarbunga runs right through Hamarinn and onwards to Veidivötn or does it run around it?

      • Skrokkalda is close to Hamarinn and Hamarinn is part of Bardarbunga which also includes Veidivotn, they are all the same volcanic fissure system.

        but the tremors that we are seeing now are in Slyssalda not Skrokkalda, and also southeast of Hekla.

    • If so, it is interesting that it is in the northern part of Katla towards Eldgja. How far is Eldgja from Veidivötn? Could the recent line of earthquakes be Eldgja instead of Veidivötn?

      • Maybe some flow from Katla – Rather unusual how well it shows up at “mjo” (Mjóskarð SIL station), I think origin maybe rather to northwest of Katla, in direction west of Torfajökull, as it shows better in this direction than north-east (towards Eldgjá.) Maybe it just passes and we never know.

      • I am almost sure this is related to the events of yesterday.

        Remember when me and Lurking were saying that this was some magma from Katla flowing down (deeper) in direction of Veidivotn. The tremor also happened at Skogar yesterday. Today we see it, also there to the north of Katla.

        I am not sure yet, could be Katla, could be even more likely Torfajokull. Could be also Tindfjallajokull (volcano north of Eyjafjallajokull) or Vatnsfjoll (volcano south of Hekla)

        And we had some poorly located earthquakes today to northwest of Katla…

        • I still say that yesterday ran the other way. The tremor yesterday started at Bardarbunga, and then started at the SILs downstream. There is a clear timeline for it.

          But today is magma intrusion into the northern part of the magma chamber of Katla.

          • I also thought that but when I saw lurking graphs, they show the earthquakes starting in Katla, late followed by northeastwards earthquakes occuring along Veidivotn. Yes, it sound strange I know. I am not sure on any of this yet.

          • I don’t think it’s magma initiated at all.

            Magma movement that is showing up, is from it infilling the area left as the plates inch away from each other. What ever reservoir is closest does the filling.

          • Lurking, I agree about the order of things.
            First crack, then magma.
            Sofar so good.
            But, I still think that yesterdays Katla quakes where just Katla quakes.
            So quake number one in Katla could be unrelated. And quake number two was far north of Torfajökull. So, I see two different swarms. Or more to the point, normal ongoing Katla quakes, and something odd happening north of Torfajökull. That northern oddity then started a harmonic in Bardarbunga. That is clear from timeline of harmonic tremoring.
            The reason for me believing this is that there has never been any evidence of Katla havin a fissure running in the direction up to, and through Torfajökull. But there is evidence of Bardarbunga having a swarm of them running down.

    • Jón is wrong on this. Highest amount of energy in the tremors was at the Dyngjufjöll SIL. And that is the SIL that is on purpose recording Bárdarbunga.
      How in the name of Hork could a SIL north of Bárdarbunga read most clearly an emplacement in Katla god only knows how many hundreds of kilometers to the south?

      Could someone explain that?

    • From trying to count pixels, I think maybe every 30 minutes. I can count about 50 pixels in every 24 hour period. An update every 30 minutes would equate to (24 hours times 2 updates equals) 48 pixels per day.

    • And that is why it is so hard to distinguish one thing from another at the SIL-plots.
      It is pretty much impossible to distinguish an earthquake from a harmonic tremor episode. They both kind of look like an earthquake. It is much simpler to distinguish them if you can look at the data in higher resolution.

  19. Mainly spurred by Diana’s issue with seeing all of the activity from in one plot…

    Why not make it 4D?

    I had been meaning to do this for some time, but it took the skill set of fiddling with the IGN data to make it doable. (I don’t care what you use, juggling that many quakes is a pain in the arse)

    • Well, one just has to love Hengill…
      And that tail of Eyjafjallajökull going straight down is specacular.
      And ontop of it TFZ…
      All of Vatnajökull look piddly in comparison.

      One thing though striked me. And that is the area of quakes up above of Hengill. I have never seen it being especially active, and on your plot there are two distinct funnels running down. Any chance of a close up? There are after all a couple of nice features up between Thingvellir and Langjökull that could get nasty if they reactivate.

      • Close up.. eventually. Right now I am rebuilding my octopus. For some reason the horizontal leg quit responding so I have to take it apart and fix it.

        In order to do just hat area, I have to extract it specifically from the data set. While I’m fighting the octopus, come up with what boundaries you would like for that plot and let me know.

      • I will…
        And I guess my big mystery for tonight will be the octopus…
        I now have the image with someone doing strange things to an electronic robotic octopus while shouting “it is alive, it is alive!”…
        I need to do something with my imagination really.

      • Nothing exotic…. an ‘octopus’ is nothing more that a filament transformer wired so that you can inject a signal into a circuit and look at the resulting trace on an O’scope. Similar to Lissajous patterns, you can use it to check for bad components without removing them from the circuit board.

        Later, someone built a dedicated version of it called a Huntron Tracker and made some nice money selling it, but it’s nothing more than an octopus.

        I built mine about 20 years ago and was setting it back up, and noticed that one of the legs was dead.

        For the digitally minded… this is analogue stuff. I cut my teeth in electronics working on vacuum tube systems. Logarithmic sweep circuits etc. This is old school.

        • Ah, then I get it.
          I just never had heard that name for it… Swedish speaking you know…
          But I still can’t get the image out of my head… Will probably give me nightmares. 🙂

    • Great Lurking!
      This is a huge work!

      In 17 years, most earthquakes happened under Hengill and Tjornes. And we can clearly see the intrusions coming deep under Eyjafjallajokull, but not as much under Katla or Bardarbunga.

      Maybe next eruptions will be at Tjornes or Hengill?
      Just my wild bets

      • You know, your buttocks are existing pretty much ontop of Hengill… You are welcome to come and visit if it blows.

    • Amazing plots. And a lot of hard work, if you had to get the data week by week.

      But surprised by how few EQs there have been in the middle of Iceland.

      • Yeah… the directory is pretty messy, I tackled it one to two years at a time. It’s a monster flat file.

        Where I ran into trouble was trying to get a cumulative seismic moment plot that matched what IMO puts out. I never could get the numbers to work. That was even using the boundaries that they used.

        With Carls revelation of the the zoning, despite the weirdness of it, and that they keep it up to date, the need for doing it isn’t there anymore.

    • Lurking, this is amazing, thank you!
      It is really clear that Dead Zone is dead, and that Hengil and Tjornes Fracture Zone win by far in the number of quakes. Although also clear the Hengill’s quakes are mostly pink and therefore small (I can’t tell what the magnitude is from the scale, the numbers are too small).

  20. What if this is related to Torfajokull. That explains the Veidivotn events yesterday, and the tremor happening north of Katla tonight (which could actually be occuring in Torfajokull).

    Torfajokull tremor would show up in north of Katla, southeast of Hekla, and in stations around Veidivotn.

    • Interesting really…
      Because there has always been a theory of there being a connection between Bardarbunga and Torfajökull… And as far as I know nobody knows if it has a southern fissure swarm. It would at least explain yesterday. And I would not rule out today entirely either.

      Horrible thought really. A parasitic volcano siphoning both Katla and Bardarbunga, talk about doublewhammy.

      • Maybe this whole action is just tectonics. After all Iceland must continue her rifiting, every day. This is just what we see.

          • In a normal setting, that would be correct. But like Hekla, the fissure vent that looks like a stratovolcano, it’s not quite the same as we should normally expect.

            Hekla is driven by the stresses that are pulling the crust that it is on, apart. Yes, it has magma ‘chambers’ and they do fill. But whether Hekla opens up and does it’s thing is also a matter of what the crust that it sits on top of is doing.

            The magma that eventually drove Eyjafjallajökull bored it’s way to the surface, forcefully. We could see is coming. We may not have known what it was, for all we knew it could have become another cryptodome or eventual pluton emplacement. The rock was solid, and the magma had to work it’s way to the surface.

            For Helka… what if the surface just pulls apart (tectonic forces), and weakens the region over one of the magma ‘chambers’? You get an eruption.

            The same thing applies to any of the ‘fires’ eruption. The magma is there, and the removal of the overlying stress just kicks the process into gear.

            That’s why I think we have such oddball indications.

            The plates eased the overburden pressure, and the magma in nearby accumulations in-filled the now lower pressure areas until it achieved a new equilibrium.

            Now that (based on my view) the magma has reached new areas, will the heat further weaken the overlying material?

            If I were a vulcanologist I would be jumping through my ass right now to get gear out there and study it.

  21. And… since we are caught up in psuedo Laki mongering.

    Some researchers who have an alternate view of the harsh winters following Laki.

    “The anomalous winter of 1783–1784: Was the Laki eruption or an analog of the 2009–2010 winter to blame?”

    Click to access 2011_grl_darrigoetal.pdf

    I still think it was Laki… but I guess someone has to come to it’s defense.

    Pinatubo in the Philippines caused a measured 0.5° to 0.8°C drop in global temperatures.

    From the video linked earlier, it was noted that Laki was emitting as much SO2 as Pinatubo, every three days.

    • 09-10 is one of the warmest winters on record here…
      What I think is that those moroons have made the standard weather mistake of thinking that their bad winter is everyones bad winter. Last real winter we had was 96-97… I blame that weather on the Dolphins.

      I’d still go for Laki as the cause of the chill.
      I have my familly books dating back to a while before Laki, and the church books, so I have started to go through them for weather and volcano coincidences. Sofar I have 3…
      I have missing summers ín 1784, 1816 and 1913. Complete with stories about the fog of 1783.
      Albeit these books and records are of local nature they contain some rather nice testimonies and death records. And the most fun thing is that 1816 is the one with the lowest effect on the crops (there actually was one, but small). I am going to write something up one of these days.

      • Thats really nice Carl. Maybe 1816 was more spoken about because it was a more recent age. I think 1783 was at least as dramatic. I think your 1913 was related to Novarupta, probably the largest eruption of the 20th century.

        If you could go backwards, you will find maybe the 1600 event or the 1453 event

        • I could get back to 1652 with the books I have. Before that there where no humans living where my family hails from (yes, there where Sámi, but they where not strong on writing things down).
          But if I ever get down to the central archives I could pick the data from a place that had churches at the 1600. 1453 is a nogo though.
          1913 is decidedly the 1912 Novarupta eruption. It was actually my grandmother who made me think about looking through that year. She told me when I was a kid about that summer, and how they did not get any crops, and that there where ice in the morning on the puddles, and that there where snowpiles remaining throughout the summer, and of snowfall happening in july. She was at the time 13 as that summer didn’t happen.

          I though found a bit of a nutty year. summer of 42 was bad, and the winter 42/43 was really cold, the worst on record regarding average temperature (europe). But, I can’t find any corresponding volcano, so I guess not everything is volcano related. And, I have a hard time thinking the firestorms in europe could have amased that much particles in the air to blot out the suns energy.

      • We also have had real mild winters here in Canada. The two weeks solid of -40 in mid February is not longer for at least over a decade now. This winter is very “unwintery”, we got rain, and rain, and rain. It is just past mid February, and it feels like late March. Meanwhile, Europe is freezing over. I don’t know for the rest of the world, but there is a definite warming trend here.

        • Northern Europe is not freezing over.
          It is just that southern Europe sees winter for the first time in two decades.
          And that is just normal that they get now and then, warming or no warming.

  22. Alaska’s Aleutian Islands has rumbled to life and is at risk of a sudden explosion, scientists said on Sunday.
    Kanaga Volcano, located 1,200 miles southwest of Anchorage near the port city of Adak, had a tremor Saturday morning followed by other seismic activity for about an hour, said the federal-state Alaska Volcano Observatory.
    , satellite data detected what is believed to be a thin ash cloud emitted from Kanaga
    lots more in the article

  23. And some really strange Swedish new…

    They just dug a dude out of snowed over car out on a desserted forrest road. He was apparantly alive after a whopping 2 months in the car. Durin those two months we had two weeks of between -25 and -30 degrees Celcius.

    I guess Subaru has a new sales pitch.

    • Yes, I read that. Apparently it was just some guy from central Sweden, deciding he has had enough of life there and drove to Norrland and parked on a remote road in early December. Then stayed in the car for 2 months under all that snow and last ate anything on 19 December! Amazing he is alive. Apparently he survived by eating snow. Also, since none of this is a crime, the police can’t really ask him why he did what he did and so there are plenty of speculations around…
      Here’s a photo of the car:

      • The really odd thing, it would have taken him two hours to walk out of the forrest… And it would take me about 3,5 hours to walk where he was found.

        I guess that in the end it will show that he was “foonny in da head”… Because he so apparantly wanted to be exactly where he was.

    • Err… food?

      2.2 kg of body fat is about 3500 calories (kcal). For a sedentary male about 178 cm in height, and 91 kg, that’s about 2500 calories per day. In extreme, maybe 1500 calories per day.

      Let’s say that he/she/it managed to get by on 1000 calories per day. That’s about three and a half days per pound of fat loss. In sixty days that’s a loss of 20% of body weight (in fat) leaving an emaciated 72 kg ghost of his former self.

      But that’s assuming that he had that much fat to start with. (in this case, the fat was used for what it was intended, food reserves)

      Water, well, unless he was collecting it from the snow, he’d be dead with out water.

      It’s not implausible, but it is the extreme. Glad it wasn’t me.

      • Hang on, something with Imperial systems has gone wrong here. There are 2.2 Imperial Pounds to the Kilogram. A Pound of fat equates to 3,500 kcal if you are trying to lose weight, so 1 Kilogram of weight loss would be 2.2 pounds, and a kilogram would be 7,700 calories.

        • The bane of trying to switch back and forth between systems.

          There very well could be an error there, so feel free to re-calculate. It was intended as a quick sanity check.

          • I think a doctor said he’d lose something in the order of 20 to 30 kilos in that time, the igloo effect might have kept him at around 0 degrees rather than colder – but there was some speculation of semi hibernation reducing the effect, though that was disputed.

          • And one should remember that he had a bit of food with him, and as it sound a horkload of beer cans…
            He most likely went out into the woods to drink himself to death.
            To actually sit in a car in the woods in the winter drinking untill you fall asleep should do you in. I guess he had a too good sleeping bag with him for actually freezing to death quickly. And after a while the body gets better at handling the cold, normaly by burning of severe amounts of calories.

  24. Somebody commented earler that on pixelwidth on the SIL-plots are about 28 minutes 48 seconds. Let me take Mjoaskard as an example.
    During the last few hours it has had microceisms (mini-quakes) ranging from every other minute to about every ten minutes. Several of those micro-quakes fit into the same pixel wide stapel on the SIL. And since it goes on for hours… well, it sure looks like a harmonic tremor to anybody looking at the Plot, but it sure is not.
    Why there are microceisms at Hekla now is a good question, but Mjoaskard is about 8km from Hekla, so my bet is that it is a local Hekla phenomenon.

    Here is the public SIL-link for Mjoaskard.

  25. Before you all go to bed, I would like to thank you for some wonderful posts. Great stuff, so much to learn and ruminate about.

    • Katlas activity has a completely different look really than the Heklas miniquakes.
      One component looks like a bit of wind.
      But then we have other things too.
      For instance there is a clearly visible harmonic spike that lasted for 3 minutes close to Smjörgil station, but it is not visible anywhere else. And then if I go to Slysaalda I get microseisms, not any tremoring at all.
      No, I still go with what is happening in Katla is inside the caldera. This is somethng going on in the main volcano, not any fissure thingies.

      It is Iceland, there are normaly several things going on at the same time. This is one of those instances.

  26. And now I am very much overdue for some sleep. My eyes can’t take more looking at squigles slowly moving over the screen… The SILs are really much easier to follow then the live feeds.

    Shleep well everyone!

  27. @ Lurking….. My hero! Many, many thanks. The above comments cover most of what has become very obvious in the plot.
    Eyaf’s “tail” is most spectacular. This was an eruption. Hengil’s “Tail” cannot surely be created by fracking, and it hasn’t erupted . Can it purely be tectonic or is it a a mixture of both and we may see an eruption relatively soon?
    The “Dead Zone” is really almost dead but now not so dead I think.
    The TFZ is amazing. An arch on either side of the rift can be clearly seen.

    I shall continue to study this plot, particularly the west of Myrdalsjokull and Vatnajokull.

    ………..and I dedicate this song to Lurking, My heroic number cruncher.

  28. Six earthquakes already since midnight.

    1127572 20/02/2012 00:26:24 27.6266 -18.0332 11 1.2 4 SW EL PINAR.IHI

    1127573 20/02/2012 01:27:00 27.6235 -18.0896 9 1.1 4 SW EL PINAR.IH

    1127574 20/02/2012 01:29:07 27.7274 -18.0372 11 1.1 4 SW FRONTERA.IHI

    1127575 20/02/2012 01:45:56 27.7119 -18.0500 13 1.0 4 SW FRONTERA.IHI

    1127588 20/02/2012 03:13:46 27.7167 -18.0426 12 1.6 4 SW FRONTERA.IHI

    1127589 20/02/2012 03:21:46 27.6409 -18.0901 10 1.1 4 SW EL PINAR.IHI

    • The gap? Momentary outage. Happens all the time.

      The 0.59 tremor is still there, though not as strong as in the past.

  29. A Volcanic Eruption in Hekla, February 26, 2000
    An eruption began in the Hekla volcano at approximately 18:17 on the 26th of February, 2000. The timing of the eruption is based on a decrease in strain build-up rate recorded in the Hekla volcanic vent by a strainmeter located in a borehole about 15 km from the volcano summit. A decrease in pressure occurs when the crust opens at the surface due to magma pressure. The first earthquakes or small tremors were recorded at 17:07 at an earthquake site south of Hekla which is operated by the Meteorological Office. Previously microearthquakes were recorded at a site operated by the Science Institute, University of Iceland, situated on the northwestern slope of Hekla at approximately 16:55. At 17:20 Páll Einarsson at the Science Institue notified the scientific community of movements in the vicinity of Hekla which could signal the beginning of an eruption. At the Meteorological Office tremor was recorded at the nearest station at approx. 17:20. Fairly well located earthquakes of magnitudes 1-2 were recorded at 17:30, 17:45, 18:17 and 18:26. They were located one to two km southeast of the Hekla summit at a depth of a few km (not well constrained). I arrived at the Meteorological Office at 17:30 and notified the National Civil Defense of Iceland at 17:38 that the probability of an eruption in Hekla was high. I then contacted the Civil Aviation Administration and notified them that an ash plume from Hekla could be expected to extend to flight heights, i.e. 10 km. I also contacted the Meteorological Office Forecast Bureau and asked them to calculate ahead of time the expected direction that the ash cloud would follow and make radar images at short time intervals. At 17:31 the automatic alert system at the Meteorological Office gave out the highest alert for the Hekla region. At 17:47 the strainmeter at Búrfell showed a distinct variation, which could be interpreted to be due to magma forcing its way to the surface. Past experience of the Hekla eruption of 1991 meant that an eruption could be expected within 20-30 minutes. I notified the National Civil Defense, the Civil Aviation Administration and the meteorologists about this. The eruption then began at 18:17. The first reports from eyewitnesses were made in the following minutes. The weather radar images showed no sign of an ash plume until 18:20, but a plume at this site has to reach a height of 2 km before it is detected by the radar. On the next radar image at 18:25 the plume had reached a height of 11 km.
    February 27, 2000
    Ragnar Stefánsson

    Strain measurements
    The Meteorological Office operates a volumetric strainmeter network in southern Iceland. Strain changes were observed at these stations in association with the Hekla eruption on February 26. These strainmeters, coupled to borehole walls, detect variations in bedrock volume. Map 1 shows the location of the strainmeter network. The network has been in operation since 1979 in conjunction with the Carnegie Institution of Washington.

    Figure 1 shows the strainmeter data from Feb. 26 to March 1. Figure 2 shows part of the records in greater detail. The strainmeter at Burfell shows continuous contraction in the bedrock from 17:45 to 19:20. At the same time other strainmeters show extension or an increase in bedrock volume.

    Figure 3 shows the strain rate at stations Búrfell and Skálholt. The Búrfell strainmeter shows that the contraction rate increases rapidly to 18:17, and then decreases. After 19:20 an increase in volume is observed (Figure 1 ). It is assumed that this change in the rate of opening marks the time that the conduit reaches the surface, i.e. the start of the “visual” eruption at 18:17. The strainmeter at Skálholt does not show a significant change. It is at a distance of 45 km from the volcano whereas Búrfell is at a distance of 15 km.

    From the results of the strain measurements we can define three phases in the eruption in the first 24 hours. Firstly, the opening of the conduit to the surface from 17:45 to 18:17. Secondly, the continuing but much slower expansion of the conduit to 19:20. And finally, after the conduit is fully developed, all stations show an increase in volume when magma flows from the magma chamber under the volcano. In the first two phases there is also some kind of emptying, but the opening has the most influence on the strainmeters. The reason that the polarity varies between stations in the first and second phases is that the conduit is an approx. 7 km long intrusion. In a direction perpendicular to the intrusion, where the station Búrfell is situated, we observe contraction. However, in wide areas parallel to the intrusion, out from its ends, we observe extension. All the other stations are in those areas and Geldingaá is to the north.

    The strain changes we observed are similar to those of the Hekla eruption in January 1991. First observations however show the signal at Búrfell to be smaller now, but the other stations show similar or larger signals. We have yet to find an explanation for these differences. A slightly different direction and location of the fissure in this eruption compared to the 1991 eruption could possibly explain this difference. Right before midnight on Feb. 27 extension stops at Búrfell which could indicate that the lava flow decreases.

    February 28, 2000
    Kristján Ágústsson

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