Bárðarbunga update

Photograph by Eggert Norðdahl. All rights reserved and used under permission.

Photograph by Eggert Norðdahl. All rights reserved and used under permission.

I once again reiterate that it is Icelandic Met Office and Almannavarnadeild ríkislögreglustjóra that has the authority to issue warnings for Iceland in regards of eruptions and jökulhlaups.

For airborne ash advisories it is in the following order London VAAC and IMO that issues advisories. That being said here follows a brief update.

Almannavarnadeild ríkislögreglustjóra

This is the latest advisory issued.

The Police Commissioner in Húsavík and Seyðisfjörður have decided to close and evacuate the area North of Vatnajökull following the seismic activity in Bárðarbunga.

This decision is a safety measure. It cannot be ruled out that the seismic activity in Bárðarbunga could lead to a volcanic eruption. There is no change in the seismic activity at the moment and no sign of an eruption and but experience shows that seismic activity can be on going for a long time with out an eruption going off. This is first and foremost a precautionary action since the evacuation of the area is impossible on a short notice.

In accordance with procedure, the National Commissioner of the Icelandic Police has raised the Civil Protection level to Alert Phase. All roads leading into the area are now closed and the authorities in Húsavík and Seyðisfjörður are evacuating the area North of Vatnajökull.

The Civil Protection Alert Phase is declared; “if threat assessment shows that hazard is increasing, a preventive measure must be taken immediately to secure the safety of those who are in the area. That is done by strengthening response measures in the area, and by taking preventive actions such as evacuation and closing off the area in question. Increased preparedness and warnings are also common in this phase.”


BardagpsbNow let us play with the GPS values. Sadly I am not good at all with plotting so I do things by drawing arrows on maps. In this case I will draw arrows on an image from Google Earth. The values I am taking are from five stations. The stations used are Fjórdungsalda (FJOC, Red), Hamarinn (HAFS, Yellow), Vónarskard (VONC, Green) Dyngjujals (DYNC, Blue) & Grimsvötn (GFUM, Black). There is a slight uplift at all stations except at Grimsvötn that has had 20mm of uplift during this crisis.


I think that the lack of marked uplift is due to separation of the MAR occurring and that the magma is entering into the opening rifts. As such there is no net increase of pressure causing uplift except at the Grimsvötn central volcano.

Now, trying to interpret the orbits of the various GPS-stations is a bit of a headache. But in the end it follows the plate tectonics quite well. The side to the west of the MAR is moving northwards and the eastern side is moving southwards. The division seems to be either along the Veidivötn fissure swarm, or in between Veidivötn and Grimsvötn fissure swarms. The orbit of Dyngjuháls is most likely influenced to go strongly to the east by a local intrusion south of Kistufell. There is no evidence of inflation in Bárdarbunga.

Now for the two arrows that seems to be at odds with each other. Well, Vónarskard is south of the rift zone where the Western arm of the MAR meets the triple junction at Bárdarbunga. From the south comes the South Icelandic Volcanic Zone and then the main MAR goes up north. The plate on the map that is in the southwest is called the Hréppar micro-plate and it seems to be moving east while the part north of the Hréppar is moving to the west.

Photograph by Eggert Norðdahl. Used under permission.

Photograph by Eggert Norðdahl. Used under permission.

No wonder we are seeing such a seismic event. Iceland is having a really bad week from a tectonic standpoint.

Well, this is normally where I go and ask my brother at arms GeoLurking for a plot that explains things, but he is sadly not feeling well right now. I hope he feels better soon for many good reasons.

Ash seems to be fun

Image made by Down Under. Showing trajectories from a 10km ash column for today.

Image made by Down Under. Showing trajectories from a 10km ash column for the 21st.

Now, since this is Iceland and a lot of people remember the ash of Eyjafjallajökull halting air travel I am now incorporating a wonderful ash projection by commenter Down Under. Remember that only London VAAC can issue ash advisories. This is the most likely ash trajectory for the 21st from a 10km ash column.

All the wonderful pictures are once again taken by Eggert Norðdahl. I would like to state that Volcanocafé have been granted publishing rights, if any news agency wish to use the images, or wish to come into contact with Eggert Norðdahl for more images of the upcoming eruption, just send an email to us at our Volcanocafé email.


501 thoughts on “Bárðarbunga update

      • Not sure but if I remember correctly from “back in the days” of Eyjafjallajökul eruption the 1km with poor quality was most likely shifting in the icecap and could have nothing to do with the ongoing seismicity. I know the icecap is only an approx 600m deep but the default values are 1km.

        The 1 km will probably be altered (if checked) and location could be altered as well.

        Would appreciate it if any of the older veterans here could correct me if my memory has completely abandoned me. 🙂

  1. It’s taken me ages to get on here! Lots of traffic to the site this morning I guess. There’s a few bigish tremors coming through – and is it me, or are the drumplots ‘pulsing’? I’m pleased to see that any ashy clouds that do develop will come straight across Salisbury Plain and give us some nice sunrises or sunsets. Keep up the fabulous work (and get well soon Lurking).

    • The site is made to handle 250K views a day, so we are fine for now and even if we go above that we will get more connectivity automatically.. I am loading quickly.

  2. The Harmonic Tremor has increased a lot in the last. It is the highest tremor level since the earthquake swarm started. Far larger even…
    This combined with the uptick in earthquake both in amount and average energy… Intriguing.

    • When you say that it reached peak so far does it mean that one cannot just compare the “red spike” with the other?

      • It means that the level of energy released is higher than measured previously during the seismic crisis. As a comparison, this has an equal base energy release to Grimsvötn 2011.

      • I do not give a lot to that notion. Water runoff had a peak of 3000 units on the warmest day in Iceland. Currently we have 7000 units. The water runoff is just a boy peeing in the atlantic.

        • Webcam is coverd in cluds ;-(
          I think its breaking ground and then it defenite WATER RUNOFF following
          IMO needs recaling to 10./12.000 units 😎
          *not expert*

        • How do you explain the peaking in tremor at midday, since 11th. ( 2-4Hz ).
          Grimsfjall 2004 ( ‘sol’ data earlier) showed identical time-of-day relationship.
          So its not just a 24 hr period, its sync’d with time of day.

          • You are looking only at the 2-4Hz. Let us disect that one, the units are exponential so even the uptick there is akin to the boy peeing in the river right now.
            Also, daily tremor increase due to water runoff does not affect 1-2Hz (green) or 0.5-1Hz red.

            The water runoff is exactly even to the days, but what we are seeing now is more uneven with peaks at more odd times. If you look more closely you will see that some of the current peaks are in the middle of the night or happens a couple of times per day. It does not pan out with water.

        • Do people still believe that water is causing such a tremor spike? Like really? So I guess its also just water causing the uptick in amount and energy of the quakes. 😀

          • The diurnal water spikes are superimposed on a varying pedestal of tremor that started suddenly on the 16th.
            Two sources.
            I am not convinced the eqs follow a dirunal pattern before the 16th – haven’t seen the plot of that.

            • Some are twisting water run-off indicator in the graps:
              Its BOTTOM OF BLUE ONLY.
              I will QUIT explaining if people do not get that – peaking is quakes, only bottom before 16th are this water runoff, pure and simple. after 16th they do show, but the quakes rule, not water – and waxing and waning in this quaking are ruling after that, not the water runoff.

            • Follow the 2-4Hz blue before the 16 th in detail, not broad brush. The water run off increases during the first half of the day, declines in second half,peaks at midday. This indicates rapid water descent through ice-cap, with no delay. That tremor refects interaction with magma, as per Grimsvotn. Its re-run of Grim.
              Question is: where is the resultant steam?

              And were the eqs patterned diurnally before the 16th? It would be difficult to see how, but someone on here made that claim,

          • Look at the drum plots! There is definitely a component to those quakes that is not purely tectonic. Even the M2.7 at 10:12:09 (99.0%), the one most closely resembling a “straight” tectonic quake, is not 100%. As for the others, they are all trending towards “magmatic-gay” or at least “bi”.

  3. On a lighter note. Any Helo in area near Vaðalda can proceed at will at 0 feet AGL.
    No risks of meeting cars! Beware of fast icebergs tho 😎
    *not expert*

  4. Thank you everyone for your contributions that help me try to understand Iceland a little better. It’s like trying to win the lottery. Sometimes you get a little bit, but rarely do you get it all! My refresh button is getting a serious workout.

    • I totally concur with your thoughts Bobbi. I will add my thanks also for a superlative site here to find so much information and having the ability to quickly focus on the important things.

        • There have been attempts to locate tremor sources by comparing time of arrirval at an array of stations of distinctive signatures in a tremor record. The ‘semblance method’: eg page 3 of pdf:

            • Not an expert – but as I understand it – it is something like when the images on youtube get out of synch with the sound, and you try to work out how long the delay is by looking patterns of mouth movements – are they in front or behind the speech.

              Similarly if you have a few stations all getting reports of a tremor, and there are spikes (which are a bit like distinct lip movements) then you might be able to figure out if a particular big and far away noise was masking something else (if after the ‘normal’ delay you subtract the other far away noise signal).

              Working out the correct delay for something that moves around is going to be tricky – and probably vary based on what rock density you have in each direction etc.

              repeat – not an expert – just what I think I understood peter was pointing at.

  5. DING!
    Wednesday 20.08.2014 11:46:17 64.380 -16.276 46.7 km 2.6 31.31 24.1 km NW of Jöklasel

    If that one is even remotely correct it is very interesting. It is in the Laki/Thordharhyrna fissure swarms region. I did not think they could become that deep there.

    • and in Laki too. Urest is peaking, more than this,
      it becomes “o´shit moment” (famous last words)
      😎 … ****** / *not expert*

      • I look at these peaks, when the pressure in that are gets to much and it un zips abit more, which becomes visible to us in the form of an 3+ EQ and high energy peak. Looks to be lowering again. I would be correct in typing this?

    • Checked: Top surface at 1400 meters (area of most unrest), edge of glacier at 800 m ~ so apx 500-600 m thick glacier. Will likely make food in an hour or two, maybe 6-12+ hours to make it thrugh this thick. But depends on intensity of torch.

  6. Pingback: [16.8.2014] Island Bárðarbunga Vulkan Eruption run-up - Seite 2

  7. Can those of you that look at zoomed quakes please confirm or not if the quakes have moved more N/NW instead of NE? I am mobile only till the evening and that is the impression I get from the IMO plots.

  8. Non-seismologist here, but do any of you have thoughts about the likelihood of air traffic disruptions? And if the volcano doesn’t cause an ash plume by this Friday, does that mean it isn’t likely to at all, or the situation could continue to build up for some time?

    And am I correctly interpreting your expert comments on the siesmographs and GPS data that the consensus is that the magma is probably getting closer to erupting?

    (Sorry for all the questions! This seems to be the only place on the Internet where people know what they’re talking about!)

    • Hard to explain. Plume height is the ruling factor, and if magma is “explosive variety” or not. Contact with water produces coase ash. That does not go as high and far. So its also question of eruption strength. So far no eruption has shown abowe ground and data analyses last few hours is not public. Go back and re-read Hekla posts and other posts by Carl on this.

    • As long as activity continues, the chances of an eruption increase.

      There is no-one, not even the professional volcanologists, who can accurately predict when (and to some extent if) an eruption will take place except in extremely special circumstances as Professor Pall Einarsson did half an hour before Hekla erupted in 2000.

      Even if there is an eruption and even if the eruption is powerful enough to launch fine ash into the jet stream (currently at an altitude of 12 km above the area), this does not automatically mean that air travel will be suspended for weeks or months. The ash from Eyjafjallajökull was uniquely fine-grained and of basaltic-andesitic composition. Most likely, but do not make any decisions on this, the ash produced from an eruption here will resemble that of Grimsvötn/-fjall 2011 which caused minor disruption, mostly of a precautionary nature.

      Basically, one may as well cast the leaves or sacrifice a goat if one wishes to know whether or not one will be able to go on that trip on Friday.

  9. Before everyone gets too carried away – the final activity at Eyjafjallajökull that led to the eruption began in Jan 2010. From the last week in February, activity was continuous until the Fimvörduhals eruption began on Mar 20th. The seismic activity was just as intense during the final three+ weeks albeit possibly the avge eq was 0.3 – 0.5 mags less. It then took another 3+ weeks before the main eruption began. Although BB is NOT equal to Eyja, it could take substantially longer than the next minute… 😉

    • Aaaaand repeat! Even in the ‘smooth’ times the red line is high which indicates more activity than usual (I’m basing this on 3 years of watching Hekla graphs not on any scientific knowledge)

  10. Looking at the plot that should not be named, its very apparent how freaking strong this intrusion is, by sending a tremor pulse across most of Iceland. 🙂

  11. I don’t know why scientists say in the Icelandic media that the quakes are still at 5-10 km depth, because that’s not really what I see on the list.

    • Lobster! Are you looking at quakes with a quality of 99.0% ONLY, or are you looking at everything? If you include everything, know this – any quake not assigned a 99.0% quality has not been checked by the seismologist on duty so ignore those!

        • Just ignore those! Until a seismologist has checked the solution for a quake manually, even those at 90.01% could be wildly wrong, especially when it comes to depth. I know it’s hard to wait until they do, but in the meantime one can look at tremor and strain data or drum plots in order to get an idea about what is going on!

  12. 12:55:44 64,773 -16,720 1,1 km 2,4 90,03 15,9 km NNV af Kverkfjöllum

    What have we got here? Shallow but *northwest* from Kverkfjöll?

    • Hvusslax – 1.1 km is the default value the automatic system assigns an undetermined quake. Until it says (99.0%), which means that the seismologist on duty has revised the calculations, you can’t really draw any conclusions. All that you can say about this particular quake is that as the quality is 90.03%, it probably is a real quake, that lat & long are accurate and that the total energy release (it may turn out to be more than one quake in the same location) is most likely accurate within 10% or so.

      • Thanks. How seriously should one take the automatic system concerning depth? Does it systematically underestimate it?

        • My own experience is that even a quake (automatic solution) given an initial quality of 90% may turn out to have been several at the same x,y location but at different depths. Because of all the uncertainties, I (try to) ignore anything not checked by the seismologist except the fact that the automatic system has recorded a quake. If there are a lot of quakes, especially if in a (slightly) different location, then obviously something has happened. What I do then is I check other information such as tremor charts, drum plots etc in order to get an idea.

    • Lurk, Feeling Better? It’s 5:45am here and i can’t nuke any coffee cause it will wake DH up. Are we any closer to eruption. Make it simple for an old woman pre caffine. Best!motsfo

    • Well, I am starting to get the feeling back in my hand, so that means my brain is re-learning how to process that sensor info.

      As for eruption… Its been stated a few times that what is surprising is that no eruption is on-going. The signals seem to indicate that one is, but noting is manifest.

      For the curious about that hand bit. I just got out of the hospital yesterday from my stroke episode. (minor, but something you definitely pay attention to)

      • Take care GeoLurking. Thankful it was only minor. Bro-in-law had one early this year and was 5 days in hospital, now back to full fitness and able to drive again but as a bus driver obviously can’t do that for another year. Thankfully his was also a small stroke too.

        • Well, I don’t have to do the DOT hoops (no CDL involved). I just need the doc to say “go fer it” so I can get back to running calls. That way if something does happen, I don’t have any lawyers beating me up for running over a school or something.

      • OO, Glad to hear You are on the way back. DH had minor askemic(sp) stroke on New year’s day. Found out about his high blood pressure and diabeties then. After South Beach diet and loosing 40 pounds and cutting sugar out completely he’s doing very well. i hope the same for You… All the Best!motsfo

        • Not that You have to loose any weight! Just that You do Better! (mots mumbles about not communicating before coffee.) …….. argh!

        • Well, I had an event that got their attention several years ago, turned out to be dehydration, but at the time it spooked me into cutting some of the BS out of my diet. I’ve always hovered around 213-215 lbs, but when they took mass measurements when I got there, I was at the 105 kilo range. That’s a bit heavy for me.

          On a plus side, I did get a chance to see an MRI tech take out his sadistic tendencies as he snatched the EKG electrodes off of me prior to sticking me in that noisy culvert. I asked him if he had some latent bikini wax fetish or something… he didn’t seem to amused by that. I’m missing small spots of hair on my chest now.

      • I think I know how you feel, that episode of mine, I had headaces for a few days, I normally don’t, 1/2 of yesterday is missing, a friend found the shovel for me, I must have walked passed it for many times, my head is clear today, but feel tired, so a go slow, scary thought of loosing once marbels

    • Wife and I had a rough night. She has Apnea. We .got this new whiz-bang CPAP unit.-her mask really sucked. This was supposed to be superior to any thing out there. We go to bed get the mask on, I’ve had lots of experience with O2 masks from my aviation background. This thing was not like any thing that I have ever seen.. Stiff side panels for the cheeks and a bar of stiff plastic that fit across the upper lip. She wakes up crying. in pain. we spend two hours later , I said:-get your old soft mask”. She did. Now at 6:40 PDT, she is sleeping. Dog woke me up at
      5:30. 5 hours of sleep..Good thing my flight north to transfer the UH-1 crew was delayed.. Always embarrassing when the pilot nods off after switching tanks -then
      that exquisite moment of awakening when there is silence from the the engine(s) when the fuel in that tank is gone.. 😉
      Now Bardabunga-I think this is going to be impressive. Memories of St. Helens
      was that the old girl rattled and banged until the big one….
      Never forgot flying by Goat Rocks on May 17th….

  13. Well I for one can’t wait for the Bárðarbungabunga party ((c) Silvio Berlusconi) when she finally goes pop!

  14. If there would hypothetically actually be an eruption in this region of the current main swarm, where the star is, would this be actually Bardarbunga, or perhaps an unknown volcano under ice?

    • The idea of an unknown volcano or fissure swarm is interesting. Something is there for sure, cause dykes dont just go on random through the crust in this style. 🙂

    • I little while ago. Earthquake count:
      Magnitude less than 1 in all: 356
      Magnitude 1 to 2 in all: 1147
      Magnitude 2 to 3 in all: 198
      Magnitude more than 3 in all: 2
      Total: 1703

        • Same here – it’s gone down again now – so you may yet be right! This up and down count is actually adding to the excitement! 🙂

          • My initial refence was all-country table (http://en.vedur.is/earthquakes-and-volcanism/earthquakes/#view=table ) over 48 hrs, but did not expect it to run total over 3000 quakes. Official start time of eruption is what counts and the winner please post screenshot of his number as he/she has posted it on VC to Voolcanocafe email (ASAP when, if, etc.) and screenshot of table. I hope Dragons can sorth this out 🙂 We are ok on small error margin, +/- 5% or 50 quakes.
            Prize will be signed print of (future) eruption plume, by “Head of Photo Dept, VC Institude” co-signed by appropriate-judges (of VC clan hireacy!)

  15. Many thanks guys your good humour, patience with non-specialists (like me), and expertise is much appreciated at this worrying time.
    Any chance of upping the frequency of the updates? I understand you all must be very busy.
    Once again profound thanks.

  16. This is why I love this blog. Not only for the things you can learn and all the info, but also because of the friendly atmosphere and everyone’s sense of humor. 😀

    • Joke of the year (decided by Edinburgh Festival). “I’ve decided to sell my vacuum cleaner: well, it was only picking up dust!” 😀

      • so my favorite joke is: Doctor delivers test results to patient,” Well, Mr. Smith, i’m afraid i have some bad news for You. According to Your latest results, the slightest shock will kill You.” … At which point, Mr. Smith keels over dead. ……………. i still chuckle…

  17. Thank you for interesting discussions.

    There was an interview with Freysteinn Sigurðsson geophysicist in Icelandic Radio this morning:

    I believe it is interesting for the followers of this blog here so I will try and do a short translation for those who do not understand Icelandic.

    According to him there seems to be forming an intrusion or dyke (an underground crack) more than five kilometers below the surface. Magma is probably flowing from the center of the Bárðarbunga system into the dyke.
    It is difficult to predict the sequel but he claims there is no evidence that magma is moving closer to the surface.

    It is not known how much magma is present and how much magma can flow into the dyke so it is not possible to say whether this process ends with an eruption or not.

    Normally an eruption is most likely to take place on early stages when magma is squeezing away from the center of the volcanic systems and the norm is for the eruptions to take place near the center of the volcanic systems.

    In this case the dyke is already stretching pretty far from the center of the volcano – more than 20 kilometers. Freysteinn Sigurðsson compares the dyke to a pice of paper NorthEast from Bárðarbunga; it is more than 20 kilometers long, it is several kilometers high and the width could be about one meter. Magma that is constantly flowing into it is similar in quantity as half of Ölfusá (which would mean a magma flow close to 200 m3 per second).

    Freysteinn says it will be exciting to watch the progress and I am sure we all agree with him on that 🙂

    • “he claims there is no evidence that magma is moving closer to the surface. ”

      I find that hard to believe, look at the amount of quakes shallower than 5km in the last 24 hours. Unless they are just preparing a way up for the magma of course.


        • Well I guess that if there is an intrusion 1m wide at 5 km down there must be some surface stretching and cracking to accommodate it even if the magma does not rise further.

      • I dont know about that but I believe Freysteinn SIGMUNDSSON´s (I had his fathers name wrong up there) source of information is the most accurate awailable. If I understand correctly the site you are referring to takes raw uncorrected data on earthquakes and produces the image so it might not be accurate.
        But it sure is a great tool and will with no doubt be perfected.

      • Look through quakes that have 99% attached to them, and then look through the quakes at the eastern swarm. Most of them are still deeper than 10km in depth. This is just the beginning I think.

      • Frances – I repeat – IGNORE all quakes that do not have a quality of 99.0% as they have not been checked by a seismologist!!! The picture these automated and unchecked quakes paints is widely if not wildly inaccurate and especially when it comes to depth.

    • Yes it seemes to be – and the two images show clearly how big the difference is between corrected and uncorrected data. The top one is corrected – the lower one uncorrected.

      • Could I ask the good people here a couple of (probably dumb) questions?
        If the only earthquake data to really count is that of 99% quailty, why don’t I see any filters on the tables/maps on IMO website to include only this information?
        Can this filtered information be found elsewhere?
        And does this kind of event often result in no eruption?
        We are due for our second icelandic holiday on 17th Sept and I confess I am a little scared.
        Many thanks for your patience and your very interesting site.

        • Hi Rachael. You have absolutely nothing to fear. All possible danger zones will be closed and like you know, Iceland is a pretty big place so you´ll have plenty of other stuff to check out, far from Vatnajökull.

        • It is because those are most several kilometers wrong untill they are manually checked by a professional seismologist.
          You can find them here in the form of plots, the plotters here access a scientific datalist that is a bit hard to interpret for the newcomers, and some in here has years of experience at doing stunning plots that are easy to understand.
          I have never seen activity of this order without an eruption, but then we are in unchartered territory here. I do think there will be an eruption.

          Let me say it like this from the depth of my knowledge about Iceland and Volcanoes… I wish I had your tickets so I could go there. Let that sink in for a while. 🙂
          Just go, the Icelanders are the best in the world in regards of volcanoes. Follow their directions and you will be able to safely watch the Grandest Show that Earth has. Enjoy!

          • Many thanks for your reassurance.
            I have been reading all I can find about this but it seems a very confused picture especially when you know nothing to begin with!
            I’m sure we’ll have as great a holiday as we did last time, didn’t intend to go twice but after the first time we now don’t fancy going anywhere else! ( great people, great food, amazing sights and wonderful, wonderful scenery!!)

            • I can assure you, as an Icelander, everyone here’s cool about it and nobody feels like they’re in any danger. We’re used to eruptions and completely trust the officials to stay on top of everything. We have a great system here to monitor everything, scientists, police, rescue squads and everyone’s working together to keep us safe. As long as you’re not going hiking up on Vatnajökull while it’s erupting you’re going to be fine 😉 There’s so much to see here anyway, far away from Vatnajökull, like Snæfellsnes, the western fjords etc.

            • Rachael
              Iceland in the summer is jam-packed with volcanologists from all over the world. Its their laboratory and mostly their instruments. Barely a rock can move without them spotting it. So its the safest place to see the planet in action. I am really envious!! This could be the one holiday that is truly life-enhancing- ‘power of nature’ and all that.
              Follow guides’ advice and you’ll be fine.

    • There we got exactly what we needed, IMO plots that only contain the corrected quakes.

      Someone just asked why we need corrected quakes. It is because the uncorrected only muddles the picture, they do not help.
      Notice how sharply you can see the fissures as the magma moves.

      You can see the path the magma took, first via a normal radial fissure extending from Bárdarbunga, then it found the Fissure swarm and went up that one. Splendid!

  18. ………. Hang on Bardabunga…I need to go shopping to get some milk and essentials…… Be back in half and hour. If you could wait until after our evening meal I would be grateful……..

    Seriously I think it will be a while yet if there is going to be an eruption …there again…..Who knows 😀

  19. 13:49:38 64,678 -17,471 0,1 km 2,4 99,0 5,0 km NNA af Bárðarbungu

    Here is a manually checked M2+ quake practically at the surface in the north side of the caldera.

    • Other checked quakes in the same location. Several at less than 5 km depth.

      Tími Lengd Breidd Stærð Dýpi Gerð
      2014-08-20 13:49:38 -17.471 64.678 2.4 0.1 qu
      2014-08-20 10:59:16 -17.455 64.671 2.3 4.7 qu
      2014-08-20 08:28:00 -17.475 64.683 2.4 3.1 qu
      2014-08-20 06:58:04 -17.465 64.679 2.2 6.7 qu
      2014-08-20 05:04:46 -17.487 64.683 1.9 7.5 qu
      2014-08-20 03:29:27 -17.479 64.685 1.7 7.0 qu
      2014-08-19 22:30:55 -17.45 64.668 2.2 3.2 qu
      2014-08-19 18:26:22 -17.486 64.68 2.0 4.2 qu
      2014-08-19 17:34:20 -17.474 64.676 2.4 6.4 qu
      2014-08-19 03:20:13 -17.48 64.681 2.3 7.0 qu
      2014-08-19 02:20:39 -17.484 64.677 2.0 4.8 qu

    • One of the first signs of a smallish sub-glacial eruption would be the formation of surface ice cauldrons such as those at Katla in 2011. They were accompanied by eqs such as the one you point out that by their depth were clearly in the glacier.

  20. Any thoughts on this post of jonfr.com? http://www.jonfr.com/volcano/?p=4736

    In the one of the final paragraphs he writes the following:

    “This high harmonic tremor means that magma continues to flow into Bárðarbunga volcano at same rate as before. There is a small fluctuation in the flow of magma into the volcano, other then this minor drop in harmonic tremor. Earthquake data shows that the magma is pushing north-east at slow rate. It is unclear how much magma the sill that is now forming can hold or how long it is going to fill up. I however see clues that magma is already looking for paths up to the surface.”

    • The quake he refers to at 0:58 is presumably the one registered on the IMO site as M2.7 , 10 km deep in the caldera.

        • jonfr is pretty smart but he doesn’t always get things right (I don’t know if anyone can tell in this case if he is right or not) *I’m not an expert*

        • IMHO what JonF’r had spotted was the magnitude of the daily surges in 2-4Hz tremor was increasing day by day. We cant see them easily now, but before the 16th they were clear:
          -see Carls trace in his earlier article:

          The daily periodicity is due to ice-melt rapidly sinking to ice-cap floor down conduits. I think the tremor is the water’s interaction with terrain-surface heat, These daily surges are not found at the moment at Grimsfjall. But they were in the days before the 2004 eruption. Heat at the surface could be fumarolic with that activity increasing as magma rises.

  21. Just so people get some perspective on how deep the dike swarm is, I did some number crunching of the earthquake data. Keep in mind, this is ONLY for the 99% corrected quakes. Any other quakes, the depth is very unreliable from what I know, and judging by the corrected vs. uncorrected, this seems to be true.

    Of the quake swarm in the eastern dike that’s propogating north, the average depth over the last 48 hours is set at 11.12 kilometers deep. Of the 63 manually corrected earthquakes, only ten of those are shallower than the 10km line, with the shallowest two earthquakes sitting at 5.8 and 7.3 kilometers depth. The deepest quake is at 14km deep.

    So overall, grab your popcorn and sit back because there is a long way to go before these quakes reach the surface. Also, with such a deep quake pattern, it’s likely that we’ll see stronger earthquakes than what we have been seeing if magma starts moving upward as the rock is likely more brittle at a higher depths than it is at 10km+ depth. For now, it seems the magma is still intruding from the Bardarbunga area and pushing down the dike laterally like a mole burrowing through the ground. How long this goes on for is anybody’s guess, and if the lateral movement gets stopped while magma keeps intruding, I would imagine it will start to intrude upwards towards the surface.

  22. Idiot question: Would the magma be hot enough to melt surrounding rock? Or is it just the pure pressure which opens new cracks?

    • The magma will heat the rock, yes. This will show as a drop in noisiness since really hot rock tends to deform rather than crack. In all cases, the cracks occur due to the fluid overcoming the hoop stress of the prevailing rock. The strength of that rock will depend on sheer strength and lithospheric stress (due to the weight/mas of rock over top of it) Rock in the roof of the “chamber”/dike will have lower lithospheric stress, which is why dikes tend to work their way towards the surface. Once the pressure of the fluid/magma drops below that threshold, the dike slams shut and it stops.

      If it makes it to the surface, you get a successful eruption. If it never gets there, it’s a successful intrusion/emplacement.

    • In case you were wondering why i spend much time online. We stayed at the hotel. It is totally cloudy and if i were back home, i d s it will rain any minute and stay that way.
      Have not seen the sun today 😦 So it is occasional visits to the pool and relaxing on the balcony. ( I had really been hoping to leave the awful summer back home )

      • Sorry to hear you’ve had no sun – but you have Bardarbunga to watch! Have a wonderful holiday whatever the weather. 🙂

  23. Bazingaa!

    Thanks to IMO and their new page only containing corrected earthquakes we now know exactly what has happened.
    The swarm followed a radial fissure (like Gjálp) extending like a spoke out from the central volcano. The magma followed that untill it found (lo and behold!) the Grimsvötn Fissure Swarm!

    This is HUGE! Infront of our eyes we have witnessed the proof for a mechanical and fluidic link between two of the largest volcanoes (of their type) on the planet! If there was a Nobel Price in Volcanology this would be it.

    Flipping huge! Now we know.


    • If the Grimsvötn Fissure Swarm Theory (well, is it a theory?) is true, why didnt the swarm follow SW route as well towards Grimsvötn?

      • I would say it is a theory only in the way scientists use the word theory. It seems though to be a very strong and consistant theory.

        Here is a theory that is a theory as normal people use the word theory. The fissure between Bárdarbunga and Grimsvötn is called Gjálp (fact), my theory is that the fissure was damaged during the 1996 Gjálp eruption and that the route was blocked.
        Also, ´the pressure from Grimsvötn (central volcano) would be tremendous, so any magma trying to go directly would quickly be halted in its tracks.

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