The Long Wait?

Holuhraun lava in daylight. Screenshot from a video by Kristinn Ingi Pétursson,

Holuhraun lava in daylight. Screenshot from a video by Kristinn Ingi Pétursson,

Yesterday, the Bardarbunga crisis celebrated its first month. As our readers have already remarked, the IMO has put out an update that summarises the earthquake data over the past month. In all, some 25,000 earthquakes have been registered by the automated system of which no less than 5,900 have been manually checked by a seismologist. That is approximately 200 earthquakes per day on average or eight quakes per hour, during “rush hour”, quite a few more. This is really quite a staggering achievement by the IMO!

Summary of earthquakes from August 16th to Sptember 15th (IMO)

Summary of earthquakes from August 16th to Sptember 15th (IMO)

Yesterday in an interview carried by Icelandic News Agency MBL , Volcanologist Ármann Höskuldsson said that the Holuhraun eruption is abating. This could indicate that the first scenario might be about to happen: “Subsidence of the Bárðarbunga caldera stops and the eruption on Holuhraun declines gradually.” However, at this stage no such conclusion can be drawn as the subsidence continues even if the eruption may seem to be in decline. However, the IMO today claims that “Measurements show that the lava field in Holuhraun continues to expand. There are no signs of decreasing lava production” and ” The subsidence of the Bardarbunga caldera continues with the rate of about 50 cm over the last 24 hours.”

If we look at what could possibly be one of the best clues available, the chemical composition of the lava, there are some interesting comparisons to be drawn with those for the 2010 Eyjafjallajökull. First, Holuhraun as released by the IMO on Friday, September 5th:

Chemical analysis of lava from the Holuhraun eruption (NordVulk)

Chemical analysis of lava from the Holuhraun eruption (NordVulk)

The four first samples in the table were taken from the lava erupted in Phase II of the current Holuhraun eruption. The last sample (HRW-04) is from pre-existing Holuhraun lava, i.e. from previous eruptions in the area. The key elements to look at are SiO2 and MgO. The percentage of SiO2 indicates how evolved the magma is. Juvenile, basaltic magma usually has an SiO2 content of around 45%. The first of the evolved magmas, Andesite, usually has an SiO2 content in the 55% – 60% range. The second, MgO, can give an indication as to how fresh from the astenosphere/mantle the magma is. However, this seems to vary slightly from location to location. Now on to the Eyjafjallajökull samples from 2010:

Chemical analysis of lava from the 2010 eruptions at Fimvörduhals and Eyjafjallajökull (Niels Oskarsson/NordVulk)

Chemical analysis of lava from the 2010 eruptions at Fimvörduhals and Eyjafjallajökull (Niels Oskarsson/NordVulk)

As is readily apparent, the SiO2 content of the first fissure eruption at Fimvörduhals was substantially lower and consistent with juvenile basalt whereas the samples taken from the main eruption were basaltic-andesitic to andesitic in composition. The reverse is true for the MgO content, indicating that the Fimvörduhals eruption consisted of juvenile magma more or less directly from the astenosphere/mantle.

Volcanologists have mentioned the likelihood that the magma erupted this far at Holuhraun may be more evolved magmas that have been pushed out by the initial intrusion and subsequent continuing collapse at Bardarbunga, something that the above chemical analysis may support. Also, the report by Guðmundur Heiðar Guðfinnsson and Sigurður Jakobsson published by the IMO on Monday, September 8th, suggest this may be the case as they identify the magma as partially being “olivine-normative tholeiite” (0-5 wt% ol). The SEM analysis of some samples indicates that the (Holuhraun) erupted magma contains minor amount of plagioclase phenocrysts (<1%) and even scarcer olivine phenocrysts and they conclude that the lack of Fe-Ti oxides suggests that the samples had quenched before Fe-Ti oxides could form. As this is evidence of evolved magmas, it supports the conclusion that the magmas erupted this far are older and evolved magmas from the Bardarbunga magma reservoir. This view has been confirmed by the foremost theoretical volcanologist, Professor Haraldur Sigurðsson, on http://vulkan.blog.is/blog/vulkan/

Furthermore, the HRW-04 sample from a previous, older eruption is very similar to the recent ones. This indicates that the current modus operandi is not something new, that at least one previous eruption has followed the same pattern of a new intrusion pushing out older magmas from underneath Bardarbunga. This may be heartening news as the present subsidence of the caldera then most likely also is not a new feature, that it has happened at least once before without the entire system going into a full-scale caldera eruption and thus, that there is an improved chance of this not happening now. To judge by the current depth of the caldera, this must have happened several times previously. The salient question is if this time, the caldera will collapse far enough to trigger the ultimately inevitable great eruption.

Thus the long wait begins. Just how long is anyone’s guess.

Henrik (a.k.a. Pyrite)

IMPORTANT NOTICE:
Only the IMO and the Allmannavarnir can issue volcanic warnings and only London VAAC can issue Flight Warnings.

WARNING:
We know a few wish to go there right now. But, remember to stay on the where the wind is not blowing, this is a very gassy eruption high in SO2. Even one breath of the exhaust could kill you, so please respect any and all warnings from the appropriate Icelandic authorities!

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1,268 thoughts on “The Long Wait?

    • Thanks Islander,
      The lava flow seems quite a long way across the view, it will be interesting to see what has occurred while we have been without webcams.

      • It appears lava runs as before, only shorter
        and less “production”, feeding from shorter fissure
        altho, Southern Baby was active last time I read today (yesterday)

    • Appears not same unit (ML) here, other be Mw? Might explain this, there was “old” formula chacking ther size in beginning, in August, that had too “small window”. Might be this has not been corrected (some pages are not correct anymore, likely forgotten???)

  1. A “head’s up” for my fellow volcaholics….

    Something’s gotta give soon. The Bardarbunga GPS unit has been hopping up and down more than a kangaroo on crystal meth:

    DragonEdit: The first thing to “give” is usually human patience. / Pyrite

  2. WHAT IS GOING ON AT BARD. GPS CRASHING…..

    DragonRumble: SHOUTING is not allowed. Unless you’re a dragon 😛 / Pyrite

  3. Anyone have Drumplot access? Jon’s phones are indicating nothing! The wide glow on Bard 1 looks interesting! Tremor plots are not indicating anything unusual!

  4. I’m looking at the cam with my brightness turned up to the point of noise, I can see an occasional large clould rising up. God my gut is in knots!

      • CB I have a feeling (not scientific by any means), that this thing is about to blow. This is a big volcano. I’ve been though the St Helens dust annoyance back in ’86, still very fresh in my memory. I’m sitting with a vial of the stuff collected out of my truck bed right in front of me. When the ash reached 1g/cu M , I’d loose sight of the clock tower 1.5 blocks away (time to stay inside). The stuff itched like fiberglass dust.

        I’m concerned, St Helens was, in essences a burp. Bard could be a Bang. I know the Icelanders are reselient, but still.

        Damn, I’ve caught the first shots of this thing twice, the fissure and this one. Carl said “There will be no doubt”.

        Now BB is quiet, first round? Next?

        Excuse my spelling.

  5. I dont take this GPS oscillations too seriously. I mean come on, 3m vertical oscillations with no (or nothing above normal levels) quakes is just a bit fishy… 🙂

  6. Want something to read before bed? Try this: The Relation Between Mantle Dynamics and Plate Tectonics: A Primer by Bercovici, Ricard and Richards. Its an article from “The History and Dynamics of Global Plate Motions, 2000.
    people.earth.yale.edu
    Good stuff. Quantum cool.

    GL Edit: Added Link. For the Archival Dragon, may be a good addition to the link collection.

    A picture of Shadow trudging back to his weyr, grumbling to himself. Nice! We Approve. 😀 / Pyrite

    • Thanks. I tried to copy the link but my laptop was being a little b*&%$ last night. Even though it is several years old, the article is an excellent intro into the convection/thermodynamic component. So…thanks!

  7. Re: glow above the fog — I suspect that’s just the glow of the fissure reflecting off swirling clouds. If the caldera goes kerblooey, there will be no more fog. (And likely no more webcams.) The fog might be replaced by ash and gas, but the fog would not survive.

    • I agree, But the position appeared to be right, just right of R2D2, It was bright enough to show through the fog even though we couldn’t see through to the lights of the R2 unit, Fog cleared up some after the event.

      I’m with the Dragons when they say “There will be no doubt”,

      I’ve looked at the charts (that I have available) and see nothing. Only the erroneous GPS which coincided with the “glow”.

      OK, excited, glow from the fissure, wait till the weather clears. Watch the charts. Patience, patience, the earth is on its own time frame.

      For a moment though

      Sorry if I jumped to conclusions

        • Can’t believe how much effort it took me to ID the location of the Von station—and in fact, it is the dry caldera on the SE portion of that big mountain. But in the course of it, I had a good look at the terrain via Google Earth. Amazing place. I am new to volcanoes but a longtime lover of mountains. Now I want to visit Iceland!

  8. Something is cooking up at Bardarbnga. GPS subsidience data has gone wild and there is red glow visible even through the pea soup fog.

  9. Bardarbunga earthquake animation from september 11 to 18th
    All over 99% quality events over mag 0.5.
    Dot size is proportional to event magnitude
    Dot color is function of date – see colorbar
    Terrain elevation is shown – see colorbar too
    Data from IMO, NOAA
    Made with Gnu Octave

    I have change the threshold of quake intensity. Seing this I still don’t think it’s very useful to get so low.

      • what do you mean ? There is no scaling factor. But there probably is a “stretch” due to the 3D display. You can calculate it by converting the longitude and latitude range to kilometers. I’ll think about it.

        • according to http://www.nhc.noaa.gov/gccalc.shtml
          the distance between 65 17.8 and 64.5 17.8 is approximately 56km

          and that’s looking to be taking up about the same amount of screen space as 10000 meters vertically on your animation

          so I guess that means the vertical scale is exagerated (multiplied by about 5.5) – or have I misunderstood ?

          I like the animations as they are – it’s nice and clear when looking for patterns, but that’s how I think I understood the question posed by Evan 🙂

          • Yup that’s it. But i’s not exagerated (I mean I don’t modify the figures) , it is like I was cutting or shortening the Z axis. Depends of your perspective (ha ha )

    • Nice. Shows clearly that there are “EQ columns”, meaning the magma for these various events originates at a common source [at depth], and is traveling vertically. The only apparent lateral dike intrusions occurred very near the surface. I see no evidence Bardarbunga is the source of the current fissure eruption. On the other hand… it does all appear to be part of the same “pressurized plumbing system”.

  10. The long wait… keeps me wondering: what if this dark veil on the cams symbolizes the end of an eruption – the big boom that never happened, at least not during our short life spans?
    Perhaps Bardabunga will be still hidden in the mist of the unknown for generations to come – and darkness is all that will last when it is all gone.
    Yet, maybe not so. Just thoughts assaulting my poor tired mind.
    We are such brief passengers in this life and Nature so long lived…
    Likely not meant for us to unveil its truths.

  11. From the weather observations reported by IMO the wind is starting to come from a friendlier direction and a little stronger. Is there any sign of the fog lifting?

  12. Hmmm, that red glow and a whole lotta shaking goin’ on at Bardarbunga…coincidence? I think not!

    Do you want to know what time it is in Iceland right now? All you have to do is just look at the time and date index by your username. That’s GMT(Greenwich Mean Time), also the same as UTC for the most part. Iceland is entirely within this time zone.

    In case any of you ask about the UK, whether because of the Scottish vote for independence or not – it is currently 1 hour ahead of GMT due to it being on BST (British Summer Time) about 7 months of the year. The UK will revert to GMT on October 26 of this year.

    • And our favourite volcano is still there doing its thing. Plus Scotland has chosen to stay with us 🙂 A good start to the morning.

        • … but, I would have vvoted for pizza, so I dont have much of an opinion.

          “That was in the spam box. I took it out but now your avatar looks strange. Will there be a day I understand such things? GeoLoco”

          GeoLoco – take a second look please. a) Wrong Gravatar, b) spelling “Geolurking”, common case L?!?, c) nonsense message. duh! / Pyrite ROFLHHB

        • CNN took a poll before the Scottish vote. It isn’t clear who they polled; apparently just the act of polling suffices for them. Anyway, the result was interesting: Yes – 52% No – 58% – apparently there was 110% participation in that poll! 😀

  13. …but then again, I don’t know. It’s probably most likely just the glow of the Holuhraun fissure. But we’ll have to wait and see what happens after the sun’s up.

    Off to bed for now!

  14. Special good morning to our scots / brits,
    Look at Europe’s map and you’ll know we (the Swiss) have a “feeling” for independence and autonomy. But as always after elections or something voted (we do that something like four times every year – we vote for absolutely everything), the best thing is to look at the positive side of the result. Don’t feel as winners or losers. Feel as one nation that took a decision. I’ll have to do that on september 28th, when I’ll stand on the looser’s side in my country where we’ll have to decide about the future of our health insurance system…
    You sure all learned a lot through the interesting debate. Everyone got a better feeling for the importance of Scotland in the UK, and we all are happy to have a strong UK. And there’s no need to find another place for all the nuclear submarines stationed near the scottish coast…
    Wasn’t meant to be a political comment. It’s just about sharing the interest we have for our neighbors. So now, UK, concerning the EU, stand together and aim for your independence. You have friends waiting outside the german-french dictators’ realm…
    Now is that sarcasm, cynicism, madness, humor, am I an enlightened visionary, only entertaining myself because parts of my work sucks? Tell me if you know, I’m not so sure… 🙂
    Have a nice Friday!

    • Morning Geo, a good no vote then 🙂 I am so relieved, it was a crazy scheme by the SNP. It has divided communities that have been peaceable up until now. I always remember united we stand, divided we fall.

      • Dear scotsfjohn. Just a note from south of the border (Whitby) to say I stayed up all night watching the referendum results rolling in. (Instead of staying up all night watching mila 1&2) Glad to see there was an outbreak of common sense and wisdom. Good to see all the “No” campaigners shouting “Yes” as the results came in. Glad you’re all still aboard, we will have to look after you a bit better. And now, back to BB, although back to bed would probs be more sensible…zzzzzzzzzzzzzzzzzzzz

        • I don’t think we are that much worse off than you in England. It is the remote geography of some parts where fairness is needed in equalising travel costs instead of capitalising on essential users. It would be nice to see more spent on access to remote areas (roads) as it would benefit tourism. Ironic is it not that one of Scotlands main incomes is tourism made up primarily of English 🙂

          • Certainly I intend to come North of the Border again at some stage, especially as I won’t now need my passport or injections………………..

            • Bleh… As a Scandinavian I had fervent dreams of bearded men with large swords assaulting travell-worn UK travellers at the border checkpoints performing force-kiltings 🙂

            • I woke up to the ‘No’ this morning and felt really gutted, but GeoLoco is right, time to move on and accept there’ll be no independence in my lifetime. However Westminster has promised ‘Devomax’ to Scotland and also promised an answer to the West Lothian Question for the English so it’s not all bad. I still plan to live there as soon as I can afford it! 🙂

            • @Carl: yes, that would be something to see! Also my cousins could have made a fortune smuggling cheap Scotch and Irn-Bru to England (some of them live north of the Wall and south of the border, and know all the back roads). 🙂

            • Devo Max sounds more like an alternative comedy cartoon to me.

              With Scottish and English ancestry, and being born in Wales, and Scottish relatives by marriage, I have steered clear of the debate. It was up to the Scots to vote, they did and now we carry on regardless of the outcome. It will be interesting to see if the Devo Max and answer to the West Lothian problem will be resolved by January. Very tight timescale.

    • “You have friends waiting outside the german-french dictators’ realm…”
      sait the child playing alone in the sandbox…

  15. Maybe the dragonlets are revving up the fire deep down in the cavernous mountain reserves of magma, so to get their next meal warm if not hot, and by now the glacial lake below the pluggy ice is starting to boil? Don’t you see the huge bubbles of boil in the erratic behavior of the hapless GPS? But the grainy Icelandic Glacier piece is not keeping up well with all the commotion below.

    • Vu la simplicité perturbante du graphique, je ne me poserais pas plus de questions. En zonant par ici et en ayant lu les quelques articles rédigés au sujet de l’Islande et de Bardarbunga, tu comprends probablement bien plus que l’athlète qui a dessiné ce machin – dont on ne remettra pas en question la volonté salutaire d’avoir tenté une approche vulgarisatrice permettant aux laïcs de se faire une première idée…

      • I was very surprised to find that I sort-of understood that even before submitting it to the mercies of Gargle Translate. My French teacher of many moons ago would have been astonished at my achievement! 😀

    • Hello, icelandic for caledera is sigketill or askja. Askja is of course also the name for the famous caldera volcano…

      Erm… Katla anyone? / Pyrite

        • And the Dutch got it from where? That’s right, raiding Norse and Danish Vikings during the 9th Century – “Kittli”. And beyond that, who knows.

          PS. You Dutch were such a meek people! It took first the Romans and then the Vikings to make something out of you. 😛

  16. For those who were confused about Geolurking’s ruminations on how caldera’s react to under pressure and edifice load (in this case there isn’t much of an edifice apart from a bit of ice), I tried to put it schematically.

    Basically the theory posits a zone of reverse faulting that starts around the cavity inducing stress higher up at the surface which then exhibits normal faulting. Eventually the two zones meet up and you have a block or piston that has lost or maintained its integrity to a greater or lesser degree (i.e. it falls into the cavity as a jumbled assortment of rock or drops as one block like a piston or something between the two).

    Right that’s the theory. Why doesn’t it work here so well? Looking at dfm’s plot, it looks like the quakes actually got deeper over time rather than shallower and secondly, if all of the quake activity is due to subsidence, then the zone of under pressure (It’s not really a cavity, just an area of lower pressure) is pretty deep, about 12 km or so.

    • btw, note how the lower zone displays exactly the same cone-shaped plug posited in one of the first papers discussed here. (you could draw in your own little zone of crystal mush for the shallow chamber like this and you’ve basically got the same model as suggested by Nettles and Ekström:

          • A bit about Brazil.

            During the days of Bob, one of the late quake swarms spread out into a diffuse front of quakes headed out away from the island. From the dynamics of it, it appeared to be a sill emplacement at several km depth. Then we noticed that it had a general motion pointed in the direction of Brazil. Renato has long lamented the lack of interesting volcanic stuff down in his country, and it appeared that Bob was going to send a finger of magma down for Renato to sweat. Sure, it would have taken a several years to get there, and it would have had to intrude into and jump through the mid Atlantic ridge, but we through it was funny.

          • Hi, Bruce, Thanks for the Hi and Hi back… don’t have much time to be on here… sure missing it. Too much stuff to do for the family and You know how they demand attention…:) All the Best! motsfo

    • A very, very helpful diagram, thanks. I couldn’t before fathom what “reverse faulting” meant.
      It seems to me that the downwards arrows represent movement of material, but the upwards arrows show forces — the caldera rim of Barda is only very slightly elevating, for example.
      It also occurs to me that the diagonal lines just above the magma chamber can be thought of as a natural, incomplete arch (well, in actual 3-dimensional terms, an inverted funnel). Some quakes, then may represent giving way of parts of the crest of this incomplete arch. Such quakes might be expected to promptly cause caldera subsidence.

  17. Hi Bruce, why would all the earthquakes be caused by subsidence? Would it be logical to have some caused by the upward motion of magma?

    • possibly. But if the model is correct then upwards migration would inflate the upper chamber (pushing the upper chamber floor downwards) – at least that is how Nettles and Ekstrom described it http://onlinelibrary.wiley.com/store/10.1029/98JB01392/asset/jgrb11517.pdf;jsessionid=A6158C4184D7A04B38B8BF082DD6EADC.f01t04?v=1&t=i098bkf2&s=2c8617c3308a29e5e40163142063dfd6ceefce69
      The big question then is would we see deflation at the surface at the same time as the upper chamber inflates? And if so, wouldn’t there be more surface manifestations, fumaroles, harmonic tremor, etc. ?

      Like just about everything to do with volcanoes. One question leads to a million more..

      • PS sorry for all the typos and GeorgeBush-type malapropisms… hope I’ve edited them all out… went out last night .. might not be such a good idea to be writing too much this morning 😉

        • I can’t remember, what is the reason everybody is saying that the upper chamber is deflating?
          Just the glacial ice surface descending with all of its 800 or so meters does not cut it for me.
          Even if upper chamber is deflating, magma may still push from under the lower chamber… Anyway this is supposed to be a hot spot, actually somewhere right under our beloved volcano (with sharkanoes etc), though “right under” should be understood in context – in geology we easily brush off a million years or so…
          There is still space between upper and lower chamber, even in this model.
          But seriously, there were cauldrons in the ice SE off Bardarbunga, me thinks, early on in the story. Anyway the crust is supposed to be quite thick under Barda, so there is still plenty of room for the magma to reside well before it would appear and wreak havoc. Nothing like the fools questions…
          It quite appears that I have become swept away with this Barda-question, so questions abound, and I know some will never have an answer…

          • Lapillus all good questions! Wish I knew the answers! The subsidence in the caldera floor is a good sign of deflation (even though it is only 1 – 2 m at this stage). The Nettles Ekström model, however, posits exactly what you were suggesting. That the shallow chamber can inflate and push down at the same time, resulting in subsidence at the surface. I dunno, sounds a bit far fetched to me, but who knows?
            Personally I think this conical shape that Nettles and Elkstrom describe is the natural shape under a caldera (see Acocella’s work on this – Rhyolitic Troll/Geyser Soze posted a link to this a couple of days ago) and it is also the same geometry Geolurking was talking about yesterday. I don’t think the shallow chamber is a major player in this whole scenario.

            Ok, there certainly appears to be a shallow chamber as this explains the cauldrons off to the SE at the beginning that were most likely fed by a radial dike from the shallow chamber (wild presumption on my part) and the way the caldera responds to regional stress indicates it behaves like a hole and not just a block of country rock. But I don’t think inflation/deflation of the upper chamber needs to be taken into account to explain what we are seeing. Rather I think everything we see can be explained by the dike, evacuation at depth (like 20 km) under Bardarbunga to the dike and subsequent kneading and slumping of Bardarbunga.

            just my 2c

            If this is right, we could see a lot more slumping (sorry, but 2 m is nothing compared to what we might soon see) and no magmatic event at the main crater, or possibly a moderate ring fault event. Maybe this upper shallow chamber is a bit of a ghost and doesn’t really exist in any major form (though as I stated above this doesn’t tally with what we are seeing).

            Two more points that should be borne into consideration.
            1. has anybody calculated the drop in volume of the 700m glacial ice if it melted? How much of this could account for the slumping of the surface (mind you, I don’t believe this for one moment as we have seen uplift on the rim that is consistent with the massive ring faulting expressed by all the quakes)
            2. Normally calderas only form when you have an aspect ratio of 1:1 or higher (width/depth). If the chamber is any deeper than that the lid is generally strong enough to hold its own weight. Why is that different here?

            • btw, while I was at it, I modified the model to account for the inward dipping /outward dipping geometry at Bardarbunga:

            • Ice is about 90% of the density of water. So to get a drop of 1 meter, you should melt about 10 meters of ice. Melt the entire ice cap and the drop would be 70 meters (and the lake 600 meters deep). Ice melt is not impossible, but note the sharp drops after some of the deeper earthquakes. That can’t be instant ice melt.

            • I did a few figures on melting when they first gave figures for the ice slumping, but the biggest vaiable was the amount of air in the ice – glacier ice being derived from snow usually has a lot of air in it. Anyway, you have to melt a lot of ice to get enough decrease in volume to account for the observed drop in the surface.

            • Geyser Soze,
              They are impact craters. They might look superficially similar to calderas but are fundamentally different. What was the point you were trying to make?

            • Just thought they were cool pictures☺and trying to visualize the role of ejecta column collapse in the formation of a caldera floor😆

      • Is not that a case of trying to push from a low pressure environment (surface)into a high pressure environment (magma )chamber,unless a situation of under pressure is introduced for example ,eruption or partial emptying of chamber,or perhaps rifting and then edifice load can play its part.Also because the under pressure is not stable the subsidence would have to occur simultaneously?

  18. Just checking (manual fraid) all the EQ for Bárðarbunga for the last 18hrs have been on the northern edge nearer the GPS, previously there seems to have been a pairing between north and south. one wonders why

  19. Now I know why it was called “The Long Wait”.
    It was premonition of the long wait before we would get gui drumplot feeds back to see.

  20. Of course when the fog finally does lift, it will probably be because of a SW gale and the dust storms will be back 😦

  21. The fog still lingers at Bardarbunga but not so in Scotland.
    Status Quo in the UK but maybe Yes and No people can now work on towards true unity with both sides addressing grievances and inequalities.
    Her Majesty can now continue to relax in her holiday home in Balmoral but there is one Clan that has been, in my opinion totally ignored and not given due coverage during all the furore
    A group without whom Scotland could never have be called “The Brave”.
    The Haggis.
    I ask that we all pause for a moment and reflect on this Iconic symbol of “Freedom”. For we are all free in the UK. Free to speak our minds. Free to worship as we chose. Free to make decisions about how we are governed. I think the whole UK should now start a movement to protect and respect the Haggis and all the wonderful heritage it represents.
    I have gone political. I am sorry. I plead not expert in all this .

    • Being political should be allowed if it’s about celebrating freedom of speech, religion, love (amongst consenting adults) and that kind of democratic stuff.
      Yes, democracy means giving power to the mob that can be quite idiotic, but freedom is such a cool thing. And it allows me to live. Some boneheads in my village would have had me burned some centuries ago for comparing Odin and Zeus with Allah and his christian pendant and Shiva and so on… No I’m here happily trying to imagine what they were before the big bang…
      Did I expand politics to religion? Geeeeeez, I’m no expert, of course. 🙂

    • It looks to have too much energy for fog. It could be cumuliform clouds forming as the cooler air moves in over the lava. It could be steam also.

      • Rising Steam. rising Fog, Forming clouds, choices choices. It least the water vapour might take some of the toxins out of the air

        • This is definetly steam rising, on humid days the steam is much more visible than on dryer days. In reguard to Carls dam, I am convinced that it will not happen in this phase, There is a good liklyhood however that the lava will manage to block Svartá, which in turn will flow over the advancing tounge creating dence steam. This will help to further halt the progress of the advancing lava and it will in turn flow to the sides further “up-stream”. We are in for a BBQ of Carls hat, it is infact overdue.I am checking everyday for a video from Sweden of this joyus occation.

          • As I said, I will BBQ my hat if there is not a lake, but since the event is ongoing I say we wait and see.
            Now, when will you be BBQing your hat? And if I remember you will do it wearing a pink thong?

            • Whatever the outcome of this I am certainly NOT taking the secret contents from the box under the bed just to please you, thongs included. BTW I recommend garlic-butter in good quantity on the whole inside of your hat, befor you put it on the grill, just like when you grill small trout.

  22. People have been getting fidgety about this:

    http://hraun.vedur.is/ja/Bardarb/BARC/

    I spent yesterday in the field with the scientists downloading data from GPS stations near Kverkfjoll.

    (they’ve dragged out the older units that need manual download every couple of weeks for this event; they usually only deploy those on GPS ‘campaigns’ where they go out in summer and intensively resurvey an area for a few weeks).

    The weather sucked; very cold, rain, fog, low cloud. Snow forecast soon.

    At the elevation of the BB caldera GPS, it wouldn’t surprise me one bit if there wasn’t snow or ice occasionally accumulating and melting on the antenna.

    • Yes ice and snow is a pesky inconvenience that causes 25 magnitude 5 quakes in a month in a place that prior to 1974(that was a good vintage😊)there were zero quakes of this size for 50 years?😃

        • I think peoples intelligence deserves to be recognized,everyone here is looking at a read out from an instrument with no other context on what they are seeing.So yes they speculate on the dips and rises and yes some it maybe ice build up on equipment or technical problems.I was trying to point out this is obviously an unusual situation that is obvious beyond any single instrument reading.☺

  23. Further to my posts above: maybe I am just very very slow.. but I suddenly realized the “shallow” chamber probably IS at about 8 to 10 km depth, judging by the earthquakes and the fact that calderas don’t normally form below an aspect ratio of 1:1, i.e. if it is 8 to 10 km wide then it is probably 8 to 10 km deep (or shallower).

    But I now don’t think the chamber is shallower than about 8 km, which would explain the outward dipping earthquakes down to 10 km (can someone else verify that please?). We don’t need to posit a deep reservoir at all if the upper chamber is that big and that deep in the crust (except as the original source of melt). 8 km deep and 8 km wide is pretty damn big.

    The outward dipping / inward dipping thing is not all that unusual, given that a normal caldera displays both. Bardarbunga just has more outward dipping on one side than normal. So in other words, we are not looking at a particularly unusual caldera geometry at all – just a pretty big one that has deflated a bit and the reverse faulting on one side is more pronounced than on the other where normal faulting dominates.

    OK, off to soothe my aching brain..

    • I’ve been keeping stats of the M>3 ‘quakes at Bárðarbunga since August 23rd. The deepest of those are two: one at 10.4km and the other at 10.3km. I then checked the IMO table for the last 48 hours. There is one, an 0.8 which was 11.6 km depth that was 8.6km E of Bárðarbunga. In keeping with your hypothesis, if the chamber is 10-11km deep then all (that I can access) are within that depth except for the 0.8. It’s so little that I’m wondering if it could be an aftershock in the rock below the chamber? Or perhaps it’s in a radial dike somewhere? Or maybe movement of magma up from the deep? Speaking of “deep”, I’m well out of my depth here! Anyway, that’s the best information I can offer you, Bruce. Hopefully someone else has access to a broader range of stats.

    • Bruce,

      Thanks for thinking out loud here, seeing your thought process is very enlightening.

      Things below the caldera are no way as simple as the drawings can express, inward, outwards, cone, reverse cone, sills, radial dikes, regional dikes, sheets and chambers all interacting and under some sort of directional pressure.

      When this thing ends ( in our lifetime or not), I am sure there will be a few experts that will take a kick at the can and try to explain the observations, it will be interesting for sure.

      What really puzzles the heck out of me is the two lines, north and south and nothing around the east west edges. There was one M5 on the west side but it was very deep. OK, so one explanation would be the chamber is in fact offset from the caldera and the rock is too ductile to manufacture M5 quakes. But you would expect there to be some sort of east west “edge” to this thing.

      The stress field diagrams ( do not want to copy the pictures here but wish I could- see Dike emplacement at Bardarbunga, Iceland, induces unusual stress changes, caldera deformation, and earthquakes
      Agust Gudmundsson, Nora Lecoeur, Nahid Mohajeri, Thorvaldur Thordarson ) tends to explain this pattern the best and all of what we are seeing is a result of the intrusion of the dike and pressure on Bard.

      The sag in the floor of the caldera is maybe a result of this alone, the almost graben like fall of the floor rather and a total roof collapse. Maybe not loss of volume of the upper chamber just a pressure drop.

      If you go back to the more extensive radar map that shows outside of the caldera it appears there are areas outside of the caldera on the east that have dropped

      Credit Earth Sciences University of Iceland

      • Hi Ian, I was wondering that too the other day when the Gudmundsson paper was getting discussed. The one thing the regional kneading theory depends on though is that the caldera acts as a hole in the crust, which implies it must be there after all, doesn’t it? Or is it sufficient to have preexisting ring faults around the caldera for it to behave like a hole in the regional stress field?

        • I know nothing about geology (first year university course and I still have my rock and mineral collection lol) but do understand a little about stress in metals so I think it correlates to some degree

          Having cracks in the substrate versus a hole would yield entirely different results I believe.

      • “What really puzzles the heck out of me is the two lines, north and south and nothing around the east west edges.”

        Well the regional stress paper explains that; the axes of strongest seismicity are roughly parallel to the initial strike of the dyke; that’s obviously the direction of greatest pressure.

        As you suggest, perhaps it’s a combination of material moving out of the shallow magma chamber, and graben-like faulting.

        • What counters this theory is the fact that he dike seems to be under less pressure or at least for sure there are less quakes. One might assume this means the resulting stress should be reduced but we have seem a marked increase in the quakes at Brad as the quakes in the fissure dropped.

          I could see there being quite a delay in reaction through such a huge mass and ductile material. The stress relief could easily be an ongoing delayed reaction?

    • Would you get the current level of subsidence via 8km deep of material on a caldera 10 km wide,that is a classic cork ,where as the floor seems to behaving like self sealing jar lid?😊

  24. I noticed that there has been som discussion wether it is steam/fog and/or eruption.

    I think that there is a simple rule to end this.. If there is a need to discuss it, then there is no extraordinary volcanic activity.

    If and when something happens it will be painfully clear..

  25. In regards of the ice melting thingy that people seems to believe in.
    That would be 1 925 000 000 cubic meters of melt water one had to take into account. That is quite a lot really.
    Obviously there has not been that volume melted at the top of the ice. So, let us move on top the bottom side melt. That idea is also riddled with problems.
    1. To melt that much water you would need significantly increased hydrothermal activity. And that would be noticed as a high amount of harmonic tremor within the caldera, and no such tremor have been recorded.
    2. A hydrothermal increase would be likely to take place at the ringfault, but that is actually sagging less than the middle.
    3. The distribution of the sag is following the pattern of a uniform motion of drop of the underlying caldera floor. And that means that the middle will sag less than the middle as the ice forms a shallow cauldron.
    4. Where did the water go? If there was that amount of new melt happening the water would have to go somewhere to explain the sagging taking place. The other alternative is that this is the drop is caused by 250 meters of melted water with a 90 percent retainment into water. Now that would have taken a hydrothermal event on a scale that not even the Grimsvötn 2011 eruption caused. And let me remind here that Grimsvötn 2011 was the largest explosive eruption in Iceland since Askja in 1875 and the largest eruption in the world during the last 20 years. I guess you now understand how increadibly noisy a hydrothermal event on that scale would have been. Or more to the point, if 19 billion 500 million cubic meters of water had melted this rapidly the entire ice block in the caldera would have been blasted away so fast that it landed in Greenland. Onwards to the “where did the water go” question. Such a large forming movable liquid water body would have been pushed out by the water pressure.
    5. To melt that much water you would need to raise the temperature 5 degres (aboutish) for all that water, and that corresponds to 96 250 000 000 000 000 calories. That is the same as 402 883 250 000 000 000 joules. Or 402 Peta-Joules and that equates to 100 megatons of a nuke (two Tzar Bomba). That is a lot of heat energy released. It is the same energy as the motion energy of M8.6 or 120 kiloton nuke. Now ponder how the harmonic tremor would have looked like for that to happen.

    Ice melt is just impossible. Live with it.

      • Nearly something like that. Then you just have to put the trolls on the right side of the blanket. They get heated up and when melting occurs, they are shot out, dissolved in the hot water, in form of Geysers… 🙂

    • Thank you for clearing that out – I was beginning to have some believe in the melting theory.
      So, basically, if ice melting (in the caldera) is causing some – if any – of the drop it would be counted in centimeters at most and it would not measure in the whole picture?

    • Cat claws are sharp today I am finding out. 🙂 Its like a family spending 2+ months at sea in a submarine under water.

      Sub leave is a must. 🙂 Just hope BB either stops its thing or goes VEI something soon. Maybe WWW 3 will start on this site. 😀

      • I think most are tired and frustrated they can’t see what’s going on because of all the fog. The bar will be open soon so hopefully everyone will lighten up. Now it’s off to work for me.

    • Ice melt is happening all under glaciers. Sorry Carl. Could not help it.
      Nobody wanted to melt all 700-800m of ice. Otherwise, would our GPS have its own little boat?
      Under Glacier, some water occurs because of the pressure. Somebody posted eons ago here a picture of Bardabunga volcano without ice – maybe my eyes are tired but I saw water.
      Anyway, under ice some amounts of water is possible. Rather, it happens. So you would have some 700 kPa under that ice – or, perhaps, correct me (assuming some 2000m elevation).
      To have some meters or even tens of meters of water – why not? Perhaps you know more than I. The water could have been there all along, just waiting for us to find out. Perhaps the underlaying rock is low permeability, perhaps not. Would it keep the water?
      However, would it have any serious impact? Well, perhaps not in the scheme of things. Still there would be some many kms for it percolate through. Unless you create a good fracture (sorry keep using you as passive voice).
      The other part is, the ice cap is supposedly on the quite uneven surface of the caldera, so it really cant slosh around, even though I think it would be cute.
      But what do I know, as many others, playing with theories with very little data.

  26. Is there any information available which type of GPS sits on Bardarbunga?
    If it is a RTK GPS, a few cm of natural drift is typical.
    A standard GPS with no correction input is drifting typical a few meters. The so called *noise* is a fairly constant factor, not worsened over short therms of time.

    • Hi Jane, I think they are just processing them quickly – the latest 2 are less than 99% at the present time – but they might feel more confident now about assigning 99% certainty. (not expert)

      • I wondered if that was it. Yesterday the running 48 hour total was 250-270, today it’s gone up to over 300. I think there was a little swarm at Kistufell earlier.

  27. From latest IMO Scientific Advisory Board Report

    “Chemical analysis and modelling, of the magma coming up in the Holuhraun eruption, indicates that the magma is
    coming up from a depth of more than 10 km.”

    • Hi Hanna,
      It’s a big Icelandic volcano sitting right on the MAR (mid atlantic ridge) AND above the hot spot.
      It’s responsible for the biggest eruption of the last 10’000 years and has emitted over 20 cubic kilometers of lava in 4’650 before the birth of the christian’s interstellar power’s son.
      Except for a super volcano going boom, I don’t know what could be more interesting.
      But I’m obsessed with Iceland as an interaction of the MAR with a hotspot and a potential old continental thingy and so on…
      It could cause an event with consequences on a global scale, like climate cooling for coming decades, and big problems at regional or continental scale, like poisoning people even in Europe. And if people think 3 days without Easyjet in 2010 were a problem, Bardarbunga could teach them humility.
      But very probably there will be just a bit more distance between Europe and America and we just enjoy the firework of a fissure eruption. Without global havoc.
      I personally watch it because there’s no reason why I shouldn’t maybe be witness of what has shaped our world and life in the past during my lifetime. The surface of our planet is not what it is because of calm phases like the last century (and no, the “recent” tsunamis and stuff where not as exceptional as many may think…). And should Bardarbunga blow it’s cork, then I wouldn’t miss the amazing pictures.
      And again a comment that ends with thoughts for the 150’000 people that will die today on planet earth, as well as for their families and friends. 🙂

      GL Edit: Fiddled with your time-stamp to put your response ahead of mine.
      Yours is more emotive and not quite as dry and boring as mine. I yield the reply sequence.
      GLoco Edit: If there’s someone I’d let fiddle my time-stamp, then it’s you…
      GL Edit: Cool 😀

    • Hi Hanna. It is because if Bardabunga does erupt it could have profound implications for other countries as well as the population of Iceland. Can I suggest you have a read of some of the very interesting information, simply written , on this link.
      https://volcanocafe.wordpress.com/essential-info-for-new-readers/
      Also at the moment Bardabunga is showing signs that it may erupt. Most of the other Volcanoes in Iceland are resting at the moment so we wouldn’t see very much happening.
      If you want to find out more about other Volcanoes in Iceland then there are lots of interesting posts here on this link.
      https://volcanocafe.wordpress.com/iceland-links</
      Dragon Diana

      Oh Dear! A late comment again! I’ll get a telling off from the Elder Dragons. Waits patiently to get her time-stamp fiddled by GLoco.
      Loco with eyes open wider than Bard’s caldera: You’re afraid of nothing, are you?

      GL Edit: Proxy time adjustment as you wish. 😀

    • Bardabunga and Grimsvotn are both monster systems in their own right. Barda sits almost on top of the center of the Icelandic hotspot. It also sits astride a de-facto triple junction.

      The larger Flood basalt events tend to come from Bardabunga related fissure swarms.

      In other words… Bardabunga can be one nasty S.O.B. if it takes a mind to do so. (apologies for the anthropomorphism but I felt that it was descriptive.)

      Example: Þjórsá Lava (circa 6600 BC) Largest Holocene lava flow on earth. Came from the Veiðivötn part of Bardabunga’s swarm.


      Image Source: Wikimedia Commons

      970 km² about 26 meters deep. Volume close to 26 km³

    • For me

      Watching Iceland because there is nowhere else in the world like this.

      Also, there are many other active volcanos but they cannot be watched like this one can

      Thanks to IMO and others, we are getting up to the second data and cameras so we can watch all of this unfold in the comfort (and safety ) of your living room

    • Actually, the Bard/fissure event is just the “soup of the day”. There is no conscious effort to focus on just a single volvcano, just what the common interest is at the time by the readers and contributors. In the past, VC has extensively covered/investigated many volcano and volcano- related events across the globe in these first formative years (Eyja, Grimsvoltn, El Hierro, Etna, Sinabung to name a few).. Plus, many of our bloggers are in Scandinavia and Europe, which were so horribly impacted by Eyja’s eruption, so there is a personal interest involved. Lastly, as you might have noticed, some Icelandic eruptions in the past have had major impact on a hemispheric scale, both in terms of climate and human suffering. I would think this qualifies the Bard event to have a much higher level of interest than simply another “burp” from a regularly erupting volcano.

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