A brief update on El Hierro

This image from the tourist bureau gives quite a good perspective on the island of El Hierro and La Restinga. One just need to lift the eyes to see the volcanic edifices looming over the villcage.

As the smoke starts to clear at El Hierro we get a much more detailed picture of what is happening. As data has poured in we can now deduce a few things.

First of all GPS figures today confirmed that this is indeed a fourth bolus of magma coming up from the depth.  The first one in July 2011 started the entire hubbub and in the end caused the sub-aquatic eruption south of La Restinga. A second bolus in January that followed the same path revigorated the ongoing eruption briefly, but was too small to keep up the pressure in the volcanic system and the eruption dwindled to a halt. The third bolus is so far the most interesting, during a few days more magma arrived than during the first one that caused the eruption. The magma arrived at the same place as for the first two (around the Tanganasoga volcano), but then it took an entirely new path and created quite a few earthquakes as it moved towards the western point of the Island. The fourth bolus also arrived at Tanganasoga, and immediately started to move south and slightly downwards.

Image by IGN. GPS data points for the uplift, figures are aproximatly 2 days old.

We still have only one set of data points for the GPS, but since it is visible on many of them it is still credible. What is a good test for if there is actual inflation or not is to check for motion in EW and NS directions. A false read normally does not show that.

The earthquake swarm is very vigorous with more then 100 earthquakes per day. The pattern is still continuing with a south and slightly down dipping motion. We will see if the hard tested village of La Restinga will have to suffer both the knowledge and the feeling of magma moving straight down under their feets.

Image by IGN.

We can also rule out any degassing or actual small eruption, what initially looked like harmonic tremor are most likely small earthquakes, there is no clear signal showing harmonic tremor to this date.

Image by IGN. No harmonic tremor showing on the charts now. So, no eruption, or no de-gassing.

There is no way to know if this bolus will cause an eruption or not. The lack of harmonic tremor says that it will at least not happen within the next 24 hours or so. But, for the residents on El Hierro the same advice is always valid, stay on top of the news.


604 thoughts on “A brief update on El Hierro

  1. I haven’t spoke much on El Hierro, but now I do see that it might be getting near a larger eruption.

    This ongoing swarm is indeed a game changer, as it indicates a significant influx of new fresh magma from deep until about 8km deep. It’s a matter of months of a few years until this reaches the surface. And then, it will last months at least.

    The future eruption will likely be efusive, long lived, and a larger volume of basalt (might have also some explosive activity because of the proximity to sea). After all, this is a shield volcano.

  2. I think there is a risk of overinterpreting the quake plots right now at El Hierro.
    We should remember that there where shallow quake activity ongoing at Balneario Pozo la Salud before the last blob of magma arrived. That one is almost assuredly caused by an older intrusion of magma. The new magma has no visible connection to the older intrusions and seem to live a life separate of the Balneario swarm.
    I would say that the behaviour of the new swarm though is worrying, it is clearly rising now.
    The Balneario swarm is not rising. So, even if that is at a “nicer” depth it will most likely not cause an emediate eruption.
    But right now there is no clear indication to if it will surface, or where. To early really.

    • Our Amazing Planet is full of Amazing Bullhork and should check their facts.
      First of all McMurdo have 3 airstrips, not 4.
      Second of all, McMurdo is not 3000 meters up in the air. It is at sea level. And the lunacy just goes on.
      Now over to see what Da Beeb has misunderstod.

      • OK, maybe that second link was not the best source, but it is very difficult if not impossible to fly to Antarctica during the winter (and I read this in several places, including blogs from scientists who overwintered at the South Pole, except I can’t find the link – one year there was someone with cancer at the South Pole and they couldn’t get the person out because of no flights, so the only thing they could do was to overfly the Pole and parachute down various equipment, e.g. CTscanner, etc., so that the Pole doctor could perform the surgery, which was lead via videolink by surgeons from US, because the antarctic doctor was only trained as a GP), that was my point.

        • I think Ranulph knows he would be on his own. And would be perfectly fine with dying there. He is one of the last of his species. Once the world held many Ranulphs, now we have Facebook and Medivac.
          That loss of initiative will kill us. Because when the last few die out there will be no new young men or women looking up and out saying, “Heck, nobody has gone there before”. And, if we ever will leave this planet it will be the Ranulphs that does, not the Zuckermans.

          There quite simply are no more Amundsens, Scotts, Torres’s, Magelheazes or even Tristan Jones’s out there. And that is why we truly in the end is a dying species. Ranulph is just the last glovering ember of what was once a species that could.

          • There are many signs that we have passed our apex as a species. We have not done anything remarkable really for 45 years. Instead we have pulled back. If you go into the wilder areas of the planet you see villages and even entire cities abandoned for good. We sit smug in our cities believing that all is well, but we are rotting from within.
            And the end goal for our youngsters is to compete in how many people they can squirt down with champagne. And yeah… Who has the coolest Facebook page. But Facebook is not to blame, we have just lost it.

          • Your 21:46 comment, Carl, is excellent.

            I also agree that we, as a species have passed our apex (but I still hope to get there again).
            Basically we haven’t done any new explorations, no bases on the moon, no landing on mars, no record going inside the planet, our to the bottom of the ocean, or inside a volcano. And also no cures for cancer or other diseases, that have been investigated for decades. Nor we have solved really any of our problems, which would be quite an achivement. I would hope by 21st century to have fixed our atmosphere, loss of life and habitats, pollution problems, fix the problems with nuclear weapons, energy needs, wars, terrotorial disputes, religious conflicts and nuclear waste. Etc, etc. So much to be done, already for decades, and we simply can’t do it. Science has failed. Our governments have failed. We have failed.

            You know what? We all have our share of responsability. At the very least, most of us vote for those who place the responsible to either create policies or supervise the millitary, industries, scientists, etc… We can’t even fix a economic crises, not even when it’s the 3rd or 4th time in recent centuries, with exactly the same situation and history books available. Our civilization is indeed a huge failure.

          • Problem as I see it is one step down from the politicians. We do not care as individuals any longer. All we aspire for is a comfy job, some attractive things to do when we are off work. A vacation trip. Perhaps a complimentary family. And yeah, Facebook…

            What nobody does is Dream the Big Dream.
            Blaming politicians is futile, no politician has ever sat a Large Goal for a Big Dream. It has always been small people who knocked on the door of the big and powerfull begging for help. In Kennedys case it was a small school kid. Read Homer Hickams self biographical book Rocket Boys. A really good book.
            So instead of harping about politicians, go out and get a Big Ass Dream, then go kick politicians where it hurts, and rich dudes/dudettes, do some giggoloing (all done by Christoph Cólon) and go find America, whatever America is.

          • I take exception to this.

            I, in fact, do have big dreams. I dream of pissing off the grandkids by not dying on time.

            But then, who am I kidding. I’ve seen the self indulgence of that generation and know full well that I will die a lonely old man. Preferably drunk.

          • Space on that porch?
            Just imagine, together there can’t be a single human individual on the planet we could not piss off… They would cordon off the city, evacuate it, and cut all communications. And as a piece the resistance free beer for life so we won’t move ass.
            Otherwise it is not to late to learn enough molecular biology to create som real zombies that could amble about. Should scare people into shape.

      • Yepp, da Beeb had checked there facts. Ranulph is fun, he must be the last British nutty explorer. For God, Kingdom and Beer, or whatever it is… 🙂 Whish I had a quarter of his stamina when I hit that age.

      • And I don’t think Da Beeb misuderstood anything, just that it’s crazy to go walking across Antarctica in winter, except if you really desperatly want to die. Is all I meant…

        • Well, at least he won’t be eaten by Polar Bears. He might get buggered by randy Emperor Penguins though… or hit with debris from the next failed Earth Sciences satellite launch from Vandenberg. They have a history of putting them down in that hemisphere when the shroud fails to separate.

    • I think it’s very crazy thing to do. To start if the temperature drops to -85ºC their buldozers might stop working (you might forget what how some materials react to such cold temperatures). This not to say that breathing and facing a tiny wind at such temps is deadly. I think he needs clearly some NASA-style equipment, otherwise he is doomed to die.

      • On a different track, I will never forget the episode where the 3 stooges from Top Gear drove to the Arctic. Never has 3 middle aged, half drunk, unfit, buffoons done so much to entertein me. One of them actually skiid the entire way (the slightly less sauced, youngish chap). So, of course it is possible. The relation to Sir Ranulph is that ten minutes of the show showed Sir Ranulph telling them that they where idiots and would die because they where not true explorers 🙂
        But if he dies he would most likely be fine with it.

        • I don’t agree with any of this b***t. I think we are at the apex of our human potential. Okay we might be about to stuff up big time, but compared to all of previous history our comfortable western well-ordered existence beats anything experienced by our forebears ever.

          Most people don’t get to look much beyond the horizon, and maybe this privilege of being able to travel the universe from our arm-chairs lacks immediate discomfort, but that suits me fine.

          • Hi Alyson, I think that’s exactly how the Romans felt at the beginning of the fifth century – and look what happened to them. The material wealth of the fifth century was not recovered until the fifteenth century. And we have a lot further to fall than they did. 🙂

          • I think you missunderstand me totally.
            I do not at all that we are at our apex in that capacity. I enjoy free healthcare, child care, the works. I well and truly enjoy living in the penultimate wellfare country on the planet.
            My rant is on a totally different plane and has to do with motivation and sense of “the sky is no limit”. We have turned inwards, and that is going to bite us.

            In history most people have never wished to go anywhere, or do anything big, and that is very fine. What irks me is that nobody any longer even tries to do the undone.

            Lovely historical answer to what will happen if we do not start to look outwards.

          • Hi Talla
            In terms of progress the Romans had central heating and hot water 2000 years ago in the UK, and this didn’t get to everyone until the late 20th century. There was also public plumbing in India 4000 years ago, before invasions broke up the cities. For me this is the kite mark of comfort and the height of civilization…..
            I guess increasing specialism and public systems narrow the scope of a lot of people in our orderly way of life. But some will always break the mould – ;D

      • IMO really hits it off tonight. They found it was more quakes
        17.09.2012 20:33:21 63,824 -19,782 4,7 km 0,6 99,0 19,4 km SSV af Heklu
        17.09.2012 20:32:54 63,827 -19,767 7,1 km 1,0 99,0 18,9 km SSV af Heklu
        17.09.2012 09:25:13 63,831 -19,773 3,1 km 0,7 99,0 18,6 km SSV af Heklu
        17.09.2012 03:02:11 63,826 -19,787 10,7 km 0,7 99,0 19,3 km SSV af Heklu
        17.09.2012 03:01:59 63,834 -19,770 3,4 km 0,8 99,0 18,2 km SSV af Heklu

        • I think they are as stumped as you.
          I can see them sitting there shouting “I found another one”. And reading up on Þríhyrningur and related volcanism as fast as they can. Because there is a minute chance it could behave like Hekla, and then with a long repose..?
          But, we should still wait for what the GPSes will tell before being to happy. 🙂

      • For the transients:

        The food energy in a 154g cheeseburger is about 359 Calories (really kcal) or about 1.502056 MJoules. A 42g Twinkie at 150 Calories is 0.6276 MJoules.

        A Magnitude 1.1 earthquake is about 2.82 MJ, or one Cheeseburger and two Twinkies.

        • If you want to get technical, the Ghostbusters Twinkie, at 35 feet long would not weigh “600 lbs.”

          Using the relative dimensions of a standard Twinkie scaled up to 35 feet in length, it would weigh about 115,647 pounds, or 52458 kg (0.398 g/cm³), and hold about 783,857 MJoules of energy, or about a Mag 4.8 Earthquake.

          And to think, Gozer the Gozerian could only accumulate a Mag 4.8 earthquake equivalent in spirit energy.


          • Twinkies are optional. This was just for the people wandering by. I haven’t touched on the Twinkie or cheeseburger analogy lately. It’s always good to keep in mind just how much SHEER POWER a Mag 1.1 quake… doesn’t have.

          • Yes. Exactly. Smallish. Yet. What caught my attention swarm seems normal , not strong but unusual in that it falls out of normally active area. The Vestmanneyjar 1973 eruption started almost without warning, but there was about 2,5 shortly before, or that night.

    • I love this mountain but I can’t pronounce it! I watch it every day as it aligns exactly with Eyjafjallajokull as seen from my house. It has a sharp shape, and very much like a nice small volcano.

      Þrýhyrningur seems to me to be a “tuya” well within the ridge that extends westwards from Tindfjallajokull. Yes, islander, this swarm seems to be belonging to Tindfjallajokull.

      • Isn’t the direction of the fissure swarms always trending NNE?
        The would make this into either a volcano on it’s own (with no known Holocene eruptions. Or a part of Torfajökulls southern fissure swarm.
        Could also be just a new fissure forming that just happen to happen under an old dead volcano.

        • IMO slap my head, no dead volcanos in Iceland, only no action from some over veryyyy long time. Yep, thts interesting “swarm”. Only single quakes before in the area. Further speculation be if the be Havain style fissure or will it be explosive (Tindfjöll is considered one of them most dangerous types, so Daily Fails must not be stirred)

        • No. fissures are not always trending in same direction.

          If you take Eyjafjallajokull, actually the mountain has a W-E orientation. To the east, at Katla the orientation turns from W-E to SW-NE (example Eldgjá).

          If you take Tindfjallajokull, there is a ridge to its west, where the earthquake is occuring (and Þrýhyrningur located), that is also oriented W-E. But past Tindfjallajojull, the ridges become SW-NE and merge with the ridges going into Torfajokull caldera, almost at same spot, fissures with same orientation also belong to Bardarbunga-Veidivotn system. It is indeed a big puzzle.

          Eventually, the fissures orientation become SSW-NNE in Vatnajokull, and to completely S-N somewhere around Askja, and then they even adopt a SSE-NNW orientation at Theisreykjabunga.

          Back to Eyjafjallajokull and Tindfjallajokull, the orientation is W-E, because further west, the plate movement is also W-E, but then it adopts a transform fault configuration, which actually results in SSW-NNE oriented mountains (and faulting is almost S-W).

          Further west, at Hengill, we can actually see SW-NE oriented ridges intersected by some W-E oriented faults (probably the beginning of the transform zone).

          I think this can make things more clear.

          In most of southern Iceland, the general alignment is however SW-NE. Almost always you will find another volcano placed NE of one specific volcano. With ridges connecting both.

          • I meant losely NNE 🙂
            But Tindfjalla is fairly unknown to me, and Eyja seem to be able to have flanking eruptions in many directions, but I do not think those are fissure eruptions in the normal sense. Just the odd innards of the volcano itself extending in many directions out from it.
            But I get the point 🙂

          • Last Eyjo eruption (14 april 2010) came out of crack more or less North to South,
            but true, some Eyjo eruptions are on east-to-west fissures.

          • Salvor, actually the fissure of Eyjafjallajokull was oriented W-E just like surrounding mountains in the region. If you extend it further east, then you reach Godabunga and then Katla.

            Almost every volcanic mountain I have ever seen in Iceland has the orientation of rifting.

          • Irpsit, the fissure came up east of Eyja, but it was in direction NS.
            And how that magma arrived there is an entirely different ballgame. Point being that Eyja probably do not have a fissure swarm.

      • Yes, Mt. “Triangle” but it has quite sharp ridge, like a knife (eroded by Glaciers) And further west of it, is low mountain, with a crater lake on top (Hvolsfjall). Just saw again when looking at Google Earth earlier.

        • Yes, and in Iceland it is difficult to say to which volcano does a specific mountain belongs. I think rifting is just rifting – it occurs anywhere, disregarding of whichever central volcano is nearest.

          Also, rifting is generally more active over a certain area, with mountains placed further off-rift becoming less and less active.

          However, my friends, Tindfjallajokull is likely to be a highly active volcano in the future, and you know why, because it is located at the very tip of the propagating rift of south Iceland. Same goes for Hekla, Westman Islands and to some degree Eyjafjallajokull.

          What is at the edge of Tindfjallajokull? Exactly the spot where earthquakes are occuring!

          • I do not still buy that Tindfjallajökull is involved. If you look at the map you can actually see the fissure line run straight up into Torfajökull. No, don’t go there tonight Irpsit 🙂 I know what you are thinking now… 🙂 Could Torfajökull be responsible for Tindfjallajökull too?
            Be that as i may. It is outside the fissure swarm.
            I could be an extreme of Vatnafjöll that has been fairly active this year. Or a formative fissure.
            But, to second guess IMO, I think they are worried more about a 7M quake coming and these being precursors. And that would be a heck of a spot for one. Nobody knows what would happen then. All we know is that the pent up energy there is large enough to sustain a 7M quake (worst case scenario).

  3. Let us follow Islanders idea about forgetting El Hierro tonight…
    I have an idea for a “competition”.

    In the spirit of Sir Ranulph and Jules Verne. What volcano would you like to go down in to surf up the chute on molten lava as it erupts?

    I opt for Vulcanus due to it’s name. Imagine screaming Vulcanus as you fly out of the crater. Somehow most fitting.

    What is your wish for magmasurfing? And, would it be possible to do that in Hawaii on their lava flows? Has anybody tried it? I feel like breaking a record! I will call the expedition “Up yours Zuckerman”. :mrgreen:

    • What there be needed for smearing on Lava-surfboards?
      How large boots needed to walk on Lava lakes?
      *nobody will take us seriusly, every again*

      • I have an excuse. I have fever, am on medication, and feel rather sentimental today…

        Wasn’t there a movie where someone put hubcaps on their feet and ran over a lava stream? Or was I dreaming that one?
        I would go for a ceramic surf board. Should withstand up to 2300 degrees if it is the correct ceramer.

        • Of course you are excused, no prob, consider me on sick bed visitation, cheering yu. Charamic board be overkill, hub caps nowdays be plastic (not old 1955 Chevy of stainless steel). Only 1,100 to 12,000 needed. More suggestions?
          I´d go for boots out of outer skin from them space Shuttles, braded with steel nets.

    • Dude…. CHIE’s noise level in that band went 3 sigma above yesterdays levels a little after 1300 UT (13:06:48 to be more exact) and has done so about 5 times since then.

      What’s going on?

          • Now you lost me…
            But I will explain better. Low frequency tremor needs a large conduit to form. 0.6 and the 0.29 Hz tremor needs so wide conduits that it is only the hotspot that fits the bill.
            So what I meant is that it might be a sign that something is moving up, and a lot of it.

          • The choo-choo analogy was partially tongue in cheek.

            During the Bob Jacuzzi fest, 0.59 hz was very strong. You could even see it on the seismos on the other islands. The general idea was that this was the deep source making the noise.

            And as Salvor points out… whatever it is sort of needs to be large.

          • I like that choo-choo analogy, especially pictoresque with smoke and all. Is it possibly to get a fix on the source (like submarine Huff-duff-ing ?)

          • And a sheepish grin from the peanut gallery….

            I was actually trying to explain to Salvor Hardin that Carl was being humorous.

            Think about that for a moment….

            This is not mind control, Think about it.

            This is not mind control, Think about it.

            This is not mind control, Think about it.

            (For those thinking I’m off of my rocker, that was one of the central themes from Shadoevision

            Narrator: “It looks like a dark dark day for Fate Pate…”

            Like “Idiocracy,” I think the underlying plot may have an air of truth. Mankind is a bunch of idiots.

        • Dunno.. it’s spotty, but there seems to be a 2.6 hour component in the spikes at the 0.58hz, 0.60hz, and 0.62hz traces.

          Probably nothing, Humans tend to pick out patterns… in nothing.

      • It could be interpreted as that and still be accurate.

        A 3 sigma event, especially when it happens five times in the next 10 hours means that it’s not some random occurrence. Something is actually changing.

  4. I would love to take a look at the test results from the permanent water sample testing facility that they have at Pozo la Salud. Because that tremor roughly coincides with the small Balneario swarm.

  5. <<<< Arrives with Bunch of grapes and get well card for Carl, draws up a chair and proceeds to put on her best sick- bed visitor expression whilst rummidging hopefully in bedside table to see if anyone has brought him any chocolate.
    ……….. Due to age and dislike of heights I would take my tin tray to Taal…..I think the feeling of being like a ping-pong ball on top of a fountain could be quite fun and the ride would end with a nice soft watery landing near the Taal Sailing Club Bar 😀
    ………… My big dream? I am determined to live to 100+ years so as to piss off a certain pension provider who would not pay out the small lump sum of £180. Instead it insisted I took an annual pension of less than £20.00. Therefore I opted for this money to be divided into 4 and paid quarterly into my bank account… for the rest of my life. 😀 It seems this is the only way I can have my revenge on the financiers…. but as a certain multibillion dollar supermarket says " Every little helps" 😀
    ……….. The search for adventure and discovery is not dead. We actually have made huge scientific strides in the last 20 years. The study of genetics is well on the way to providing cures for some types of cancers and other deadly diseases as well as the possibility of feeding the world's rapidly increasing population( Personally I think sorting world acceptable birth control out is the most important issue right now before we enter a World War situation that will dramatically cause a needed population crash in a messy way)
    Submarine exploration carries on . Youngsters take off to see their world with back packs. …But most young people are not wealthy enough to do this, they need to work to get money to raise a family and so the circle of humdrum life goes on. Many dream great dreams but like most of us, raising children and the need to work gets in the way and our dreams then rest on our children's shoulders!

    • I think we should divide the concept of the Big Dream like discovering Americas, and the Common Dream like bumming out pension providers, writing a book, getting a nice job, planting trees and so on. Those are quite often rewarding for the individual and quite worthwhile. My personal dream is to sail around the world before many of the island disappear.
      My Big Dream is to build a maglev lofting system up the side of an Equadorian volcano so we can get cheap ass space tickets. I even did the budget for it and a business plan, but this is not the era of Big Dreams. For those who wish to know, a ticket for 1 week in space (all inclusive hotell rotating for gravity) and return trip stopped at as little as 2000€
      It is amazing what we can do now on the cheap ass that before would have cost a bundly. For instance, the hotell would have been inflatable. It is actually possible to order it custommade with delivery within 6 months. We can do it, we do not only have the technology now, it has also gotten cheap.
      What I proposed was to use a souped up maglev rail system that was drawn up 6000 meter high mountin just a fraction from the equator.
      And that gives 4 direct advantages over all known launch systems.
      1. If you allready fly at 800km when igniting the boosters you need a lot less fuel.
      2. You are already 6000 meters up, well, less fuel again. (less effect that apparant)
      3. Equator position saves fuel.
      4. Launching from height lowers air resistance and heat effects, saves quite a bit of fuel.
      How much fuel do you save? Well, we calculated on a space shuttle craft type of vehicel to beginn with. But it is easier to talk about a big Saturn-5 rocket as an analogy. Saturn-5 is the largest rocket ever used, it is whopping stonker of a 3-stage rocket. Okay, about 60 percent of the rocket (first stage) is used to produce this effect, getting the rocket to 6000 meters at 800km per hour. So there the effects of 1 and 2 is used up. Number 3 and 4 nibbles away another 10 percent. So, 70 percent of the rocket would be gone now.
      What we then discovered was that a lot of things where oversized, engines for instance. To many and too big. We scaled them back in sixe and number, then we could scale other things, and so on and so forth. Ended up with 25 percent of fuel need of a space shuttle to do the same thing.

      The space shuttle was though dead before it lifted. Far to many components. It was pretty much built to be as complicated as possible. We then stole a study of what later became the Virgin Galactic Fly thingy. Revamped the shell into a boron/ceramic/composite. Then we had less than half the wieght, more savings on fuel… And a heck of a lot less of a turnaround time. You would not believe how much cash is saved if you can do a launch a day on just 3 crafts with one just standing ready for emergency use…

      I spent a bit on this one… and has never gotten laughed at as hard as when proposing it. Even the suppliers was on the floor literaly rolling with laughter as they gave price quotes. The rest laughed and called me and the others for idiots, straight into our face.
      So we dropped it in the end… Only thing that kind of saved it for me was that we got a letter of agreement with a mining company to launch equipment. Oh, the final nail in the coffin was from Equador when they even refused us visas on the ground that they did not want lunatics in their country. With that phrase.

      We live in a time of standstill…

  6. Micro update on El Hierro

    El Hierro does not really merrit a new post right now, so here is todays brief update.
    The ongoing earthquake swarm seems to loose it’s momentum and the earthquakes have centered in an area close to the middle of the “mercedes star” of the island. The earthquakes are in general smaller than previous and center around 20 km depth.
    The reason for the loss of momentum is found in the new set of GPS points. It is clear that this new arrival of magma was small, about the same size as the one in late january early february. Maximum uplift is 20mm compared to the first one that led to the eruption with 50mm maximum value, and the third one with a maximum of 90mm.
    Unless new magma arrives within the next few days the activity will dwindle out due to loss of systemic pressure as a driving force. Ie, that the pressure reaches an equilibrium with the surrounding crust thereby halting the possibility for new magma filling earthquakes to happen.
    In a way, that small ongoing swarm to the north of the hotspring bath resort of Balneario Pozo la Salud is more interesting. It has been going on and off for more than a month now, it is quite possible that it is caused by magma moving up from the June bolus that went out to the south west. If so there is probably enough magma to sustain the activity for some time and could in theory get interesting.

    • Thanks for that Carl. I was thinking along the same lines this morning and looked at iceland for some interesting activity. The MAR has been so active recently I am sure the pressures and potential energy being produced there is more likely to culminate in some visible or felt events than the dwindling fire of El Hierro……. However…… Who knows what this small island has up it’s sleeve! It never fails to cause curiosity and interest.

  7. This comment is so Lurkings fault who made me interested in Zombies when he reported on the American Bathing Salt Zombies.

    After running into a book named “Everything You Ever Wanted to Know About Zombies” a couple of weeks ago I got curious about if we should not really create zombies. Just think about all the perks.
    1. Would rapidly alter the human gene pool. All people who are overweight would be easy pray. Slimmer humanity.
    2. Zombies are very eco-friendly. Nothing has a lower footprint than a zombie, they only eat human brains, and they dont consume a lot of crap.
    3. Glocal overpopulation would solve itself.
    4. Youngsters would have ample opportunity to do heroic stuff. Let’s face it, the 40s generation was awesome and we have only gotten wimpier afterwards. What did granddad do? He saved the world from a huge evil Empire that made Mordor look silly. Dad became an investment banker. Son is sitting infront of Facebook competing about number of “friends”. Hm, development.
    5. Stabbin’ Cabbin’ would be seen as an instructional movie and be shown as “What not to do” movie in school.
    6. Would make “happy pills” unnessecary, who would have time for them anyhow with zombies lurching around after your brain? That put’s things into perspective about what is important.

  8. Just perusing around the web I came across this article:


    It is interesting in its suggestion that super-eruptions happen where the crust has been stretched too far over a large mantle plume, and cracks form at the top first, weakening the surface locally, rather than pressure pushing up from the bottom causing breaching. It suggests that Yellowstone may have been hundreds of meters or even kilometers higher when it last erupted, and it got me thinking about the egg-box shape of hot and cool areas of mantle under Africa.

    • That doesn’t work.

      Yellowstone is steadily slicing a path through a mountain chain, forming the Snake River plain. Uturuncu is in the middle of a mountain range, and is probably the next “supervolcano” based on the high heat loading that it’s taking on (give a few thousand years to cook… or months). Yellowstone has a hotspot, in thick crust Uturuncu has no hotspot.

      Iceland has a hotspot, and is over laid by one of the most reliably thinning regions you can find… a mid oceanic ridge. No “supervolano.” (by the media definition of the term, which is where it came from) However, we do get what is probably a bona-fide “LIP” in the making. (Large Igneous Province). Likewise, Hawaii sits slap dab in the middle of the Pacific Plate… oceanic crust is also some of the thinnest stuff you can find, just not as thin at the Mid Ocean Ridges.

      So… the argument of thinning crust over a hot-spot on doesn’t wash.

      Now, an alternate read of the article points to the layers above the chamber… which is not the whole crust. That falls into the “common sense” realm. But to achieve the dynamics of what the media sort of defines as a “supervolcano” (after all, it is their term) then you need a piston failure of the overlying strata, than then drops down and pushes out the remaining material. To do that, you need a ring fault system, or something that detaches the “cap” enough for it to push down into the “chamber” quite rapidly.

      Just from this plot of a list of hotspots… there should be a good correlation to known “supervolcanoes.”

      • Interesting discussion, and very much agree. It is most definitely not the overall thickness of the crust (look at the Altiplano or the other huge calderas in the States) but, by definition, you will not get a huge caldera forming unless the magma chamber is relatively close to the surface (a depth width ratio of 1:1 is commonly cited) (better check this later.. dodgy brain and all that). So sure extensional regimes .. oh man.. this is going so far into the territory of my 3rd post on Taupo.. all I have to do is finish it and send it to Carl. Check out Aocella for those who don’t want to wait.

  9. From the meeting this morning the traffic light is staying on green and the activity is just a normal phase..

    ,,The direction of the Plan of Civil protection by volcanic risk (PEVOLCA), and after receiving the conclusions of the meeting this morning, scientific working group maintains the normal phase in situation of early warning and green light of information to the public after the increase of the seismicity on 14 September. In the meeting held by video conferencing, have been present, scientists from the CSIC, of IGN, representatives of the General Directorate of protection Civil of the Ministry of the Interior, the Cabildo de El Hierro and the universities of Las Palmas and La Laguna.,,

    The full report which will need to be translated can be found on :


  10. Another interesting article only part has been translated :

    ,,The trachyte is a type of rock that is always formed under the bark. But Joan Martí, of the Institute of Sciences of the Earth Jaume Almera, dependent of the CSIC, view by phone from El Hierro which is exaggerated to speak of dangerousness and explains a Quo very clearly: that white portion “has a content in volatile of the order of the 4 or 5%, a temperature of 850 ° C and a density of 2300 kg/m3, making it more explosive”, but only represents 10% of the total mixture. Because 90% remaining (the black) is basalt, that counts with “only 2% of volatile, a temperature of 1,200 ° C and a density of 2700 kg/m3”, which greatly reduces the virulence of these volcanic eruptions.So El Hierro geologists know something: most of the magma is basaltic, and that means that it comes from the deep layers of the Earth. The mechanism by which that magma has been able to ascend from the outer core is exciting. Discovered it in 2005 Sebastian Rost and Edward Garnero (Arizona State University), and Quentin Williams and Michael Manga (from California). These geologists and volcanologists found that rushing chimneys of the Hawaiian volcanoes are assorted by what they called “roots”, through which different magma feathers (so called because of its shape of Wick) amount from 3,000 km further down. And that may explain why many volcanic islands have a very constant activity.,,

    The full report which will need to be translated can be found on:


    • Now that is interesting. 2700 kg/m³ Basalt. That’s pretty light. Basalt is typically 3100 kg/m³. Granite averages 2700 kg/m³.

      One thing I don’t think that they realize…. or have thought of… or addressed… all you need for it to be a problem, is for a large enough concentration of the white stuff to rapidly exsolve it’s gas load at the right depth in order to initiate a full on eruption. The rapid movement of material will drag the Basalt along, whether it’s low in gas or not. (Think sputtering)

      Can the white stuff occur in concentrations? Well…. its distinguishable as a separate material. The floaters had enough of it to float (for a while) at the Jacuzzi.

      I’m not an alarmist, but the opposite of alarmism is complacency. Complacency kills.

      I wouldn’t run around freaking out, but I sure as hell wouldn’t let my guard down.

      • May need to factor in this. Vesicles would reduce the density. Also some of El Hierro’s slopes are loose debris avalanche deposits from the gravitational failures.

  11. Hope I dont get into trouble but again this is only part of the articel and again very interesting:

    ,,The crux of the matter is that, even if the mantle is almost solid, does not mean that it is still, but that there are convection currents because it has a behavior that Geophysicists call plastic. These flows, as it supports modern geology, would be the cause of the movement of the plates of the Earth’s surface. Hence the curious: If these variations are what make unpredictable shocks and frictions between them and, therefore, places where there may be rashes, why do certain areas (especially Islands) where volcanic activity is continuing?Because there are these “roots” fixed who do resist this swing of the mantle and crust, and to ensure the supply of magma deep. His studies found one of these sources to the southeast of the Pacific. How do? Thanks to seismic CT, they realized that at that height, but 3,000 km below, there is an area where seismic waves spread much more slowly because there is one of those bubbles.,,


    GL Edit: You pared it back, I think it should be acceptable.

    • It would be better if you instead of just saying “it is interesting” try to explain
      WHY you consider something interesting.

      Additional comment by VC: A comment from a reader is supposed to be personal. Half of the fun is to get to know other people, and in many ways we get to learn about each other in what we find interesting and how we find it interesting. Narration please.

  12. Carl, I was thinking about the “what new adventures and explorations can be done nowadays?”

    Well, actually I read the piece today in BBC, and it says no one has ever walked to the North Pole in winter. I could try that 😀

    Or, I thought about an easier one. Has anyone ever bicycled up Hekla? Or swam across Askja?

    One of my goals in Icelands is to climb all active volcanoes in Iceland. So far, I have done little: Reykjanes, Krisuvik, Hengill, Kerlingarfjoll, Grimsnes, Hekla, Eldfell and Hrómundartindur. Some I have hiked but not until their very top peak: Askja, Eyjafjallajokull, Torfajokull, Krafla. Missing is a long list of them: Brennisteinsfjoll, Bláfjoll, Prestahnukur, Hveravellir, Surtsey, Katla, Tindfjallajokull, Vatnsfjoll, Bardarbunga, Theistreykjarbunga, Tungnafellsjokull, Herbubreid, Snaefells, Snaefellsjokull, Helgrindur, Ljosfjoll, Esjufjoll, Oraefajokull, Freminrámur, Grimsvotn, Hofsjokull, Kverfjoll and Hamarinn.

    • Hey long time lurker over here. On this one I had to react

      “Well, actually I read the piece today in BBC, and it says no one has ever walked to the North Pole in winter. I could try that”

      When I read that, I had to think to Alain Hubert and Dixie Dansercour, two famous belgian polar explorers. They crossed the antartica (3.932 km) in 99 days on foot (record). They tried to reach the north pole in winter but didn’t succeed. They managed only 246 km in 30 days while the North pole was still 1303km away. after 66 days they had to give up because there wasn’t enough ice.

      Alain Hubert also did a teambuilding with the belgian 4*400 team. They crossed icelands langjokull (80km) in 5 days with a good equipped tv-crew. Of course, they had their first snowstorm after 1.5 km. Link for the images (spoken: dutch, french, english /subtitles: dutch)
      On 5’30 and 19’50 you can see how a storm on an icelandic glacier look like.

      Also Alain hubert organise a trek to the North pole in april 2013, so if you want you can
      always participate. http://www.alainhubert.com/treks/

      from the site:

      “This polar trek is for people who want to experience something extraordinary and who are ready to dive deep into their physical and mental strenghts. Of course, one has to be in good health also and have good cadiovascular conditions. Because the participants will have to ski for long hours on the ice (in general between five and six hours) and in the same time they to pull each a 30-40 kilos sled. Not a very special task indeed.
      Besides, threre are also of course the cold conditions the group will encounter. But this is more a matter of getting used to it than making strong efforts to endure the climate. I will not hesitate to teach every participant how to deal daily with the cold.
      Being rested before the departure and following a regular training and preparation during the last three months will help you to make the expedition more enjoyable and

      Alain Hubert does also on demand expeditions, so if you want to organise an expedition on a certain icelandic glacier/volcano/mountain …

    • I thought that you actually need to trek in winter if you want to reach North Pole – not enough ice in the summer (especially this year)…

        • I knew a man from an Icelandic rescue unit who went up on Langjökull for a rescue expedition in a snow storm. They had to cross a bridge over a small river in front of the glacier during storm gusts of about 150 km/h (!). No kidding. They have measuring devices for wind velocities in their arctic trucks. They were lucky, got over that and could take the people they were looking for savely down to the valley / the inhabited land. In Iceland, they talk about ”byggð” which means the “inhabited land”, no one – with few exceptions like in Möðrudalir – lives up in the highlands (and / or the interior) during the whole year.:)

    • I think Irpsit meant actually walking on his feet, not using skis, and that is undone.

      Edit: Yes Irpsit wrote Walking. Walking in snow is far heavier then skiing, believe me for those of you who haven’t tried it. On the way to the north pole you would need to exert between 2 (ideal condition) and 50 times the amount of energy per gained meter. Skiing is the second most energy efficient way of moving the human body under it’s own power. Bikeing is slightly better. Walking on snow is a horrible mess since you sink down all the time. I would be both surprised and amazed if anyone ever managed walking to the north pole. And you would need relay stations with food. Ontop of the the risk of falling through hidden cracks in the ice is much larger on fot then when skiing.

  13. So I started to write a reply to lurking’s response regarding yellowstone and how it perhaps could erupt due to land “stretching,” across the top, and thus thinning the earth, allowing for a supereruption.
    I agree that “supervolcanoes” don’t erupt due to land stretching. This would perhaps make some sense in a rifting area, or even for LIP volcanoes, but it doesn’t make sense for the majority of “supervolcanoes” (I hate that term, so I’ll just label them massive calderas from here on). Why is this? Most massive caldera systems are formed in subduction arcs, not from hotspot or rifting volcanism. That’s not to say they can’t form in hotspot (yellowstone) or rifting (yemen?, Ischia) situations, but Yellowstone and rift supervolcanoes are the exception to the rule.
    In any case, I started scouring the GVP database for massive (greater than 10 x 10 km) subduction-arc caldera systems, and ended up getting carried away by compiling a pretty incredible list of large calderas, in which even I was surprised. Since popular media has labeled Campi Flegrei a “supervolcano” I decided to compile the list based off caldera systems that are as large, or larger than Campi Flegrei, and only located in subduction zones (organized by region). The results really make you re-think what is and what isn’t a “supervolcano”. It also makes you wonder how a volcanic system such as Yellowstone, or Rift oriented systems differ from subduction oriented supervolcanoes.
    For a frame of reference here, Campi flegrei has a size of approximately 13 x 11 km, and Ischia is slightly smaller in scale at 10 x 7 km. The caldera formed after Novarupta’s eruption was 3×4 km, and the Long Valley caldera in California is 15 x 30 km.
    For whatever it’s worth, caldera size doesn’t necessarily correlate to how large said eruptions were, as some calderas grow after multiple large eruptions over a period of time. That being said, it’s a pretty good “gauge” for judging past massive ignimbrite style eruptions. I only included active, or potentially active calderas in here, and we get a total of over 26 calderas that are significantly larger than the supposed “supervolcano” of Flegrei, and that’s only including subduction arc systems, and doesn’t account for unerupted volcanoes, or potentially massive marine volcanoes like Ioto.
    This is a good example of how media becomes fixated on 1-2 doom and gloom volcanoes, despite the fact that there are lots and lots of other worldwide volcanoes that have produced similar eruptions. It also goes to show how rare these eruptions are, considering only a few of these have occurred during the last 10,000 years (kikai, others?)
    (Alaskan Massive Calderas)
    Emmons Lake Caldera: 11 x 18 km

    (Russia & Kurile Islands Massive Calderas)
    Medvezhia Caldera: 14 x 18 km
    Pauzhetka Caldera: 20 x 25 km
    Kuril Lake: 8 x 14 km (sits inside Pauzhetka Caldera)
    Stena-Soboliny caldera: 15 x 20 km
    Uzon: 18 x 7 km
    Alney-Chashakondzha: 15 x 20 km (ring faults)

    (Japanese Massive Calderas)
    Aso: 24 km
    Aira: 17 x 23 km
    Kikai: 19 km
    Shikotsu: 13 x 15 km
    Akan: 13 x 24 km
    Kutcharo: 20 x 26

    (Indonesian Massive Calderas)
    Toba: 70 x 30 km
    Tondano: 20 x 30 km
    Ijen Caldera: 20 km Wide
    Tengerr Caldera: 16 km Wide

    (Philippines Massive Calderas)
    Taal: 25 x 30 km
    Laguna Caldera: 10 x 20 km

    (Italian Calderas. Only listed for comparative reference)
    Ischia: 10 x 7 km
    Campi-Flegrei: 13 x 11(?) km

    (Turkish Caldera Volcanoes)
    Erciyes: 14 x 18 Km

    (Mexican Massive Calderas)
    Los Azufres: 18 x 20 km
    Los Humeros: 15 x 21 km

    (Northern South America Massive Calderas)
    Chacana: 32 x 20 km

    (Central Chile Massive Calderas)
    Maipo: 16 x 20 KM
    Caldera del Atuel: 30 x 45 KM
    Calabozos: 26 x 14 KM
    Uturuncu: (unerupted, but likely huge if it follows other altiplano complex calderas)

    (New Zealand & New Guinea Area)
    Rotura Caldera: 22 km
    Okataina: 16 x 26 km
    Taupo: 30 x 40 km (includes other somewhat smaller taupo calderas in area as well)
    Loloru Caldera (new guinea): 10 x 15 km

      • Keep in mind, these were only subduction arc calderas. One plot I think would be very interesting, would be to look up the dates from said caldera forming eruptions, and plot them against those co2 plots that you loaded here a few weeks back that dated back roughly 70,000 years. Naturally, you would probably need to compile a list of hotspot & rift calderas as well for the purpose of accuracy.

    • Icelandic calderas, similar or larger than Camp Flegrei:
      Torfajokull: 16x10km
      Katla: 14x10km
      Bardarbunga: 12x10km
      Askja: 12x8km
      Hofsjokull: 11x7cm
      Krafla: 10x9km

      As in all calderas, problem is: some were formed by subsidience; i am not sure which were formed by a massive eruption.

      At least Katla and Bardarbunga seem similar to Camp Flegrei, with the agravated fact of having a thick ice cap on them.

      But smaller calderas could have very violent eruptions that could result in larger calderas in the future. Oraefajokull, Esjufjoll and Tindfjallajokull come to my mind (all around 5km wide).

    • Also:
      – Santorini, Crete, 12x9km wide
      – Cerro Galán, Argentina, is 30x20km, also very large, and probably still active.

      La Garita, US, is 75x35km wide, but considered extinct.

      However its the small calderas that are more likely to eventually one day form very large calderas, result of very large eruptions. Somehow some smaller calderas come to my mind:

      Baekdu, North Korea, 5 km wide
      Sete Cidades, Azores, 8 km wide (probably larger underwater calderas nearby)
      Novarupta, Alaska, 4 km wide
      And of course Uturuncu, Bolivia.

        • Ngorongoro is a shield volcano. There is a big difference between calderas that result from shield volcanoes, and calderas that result from a single event collapse.

          Also, you know more about the Icelandic volcanoes, but aren’t the calderas largely formed from a multitude of gradual eruptions, rather than 1-2 large scale eruptions? Most of the 10km + calderas are mid to high VEI 7 events. I don’t believe anything of that power has ever been present in Iceland (not counting fissure eruptions, which are in a way, their own thing)

          • It is horseradish that Iceland can not produce VEI-7 eruptions. It is just that we have not seen one recently. Krafla for instance had one when it construced Krafla-1 crater (the larger outer crater). There has also been one out at Langjökull and at Askja and Bardarbunga. There are most likely more of them hidden in the ‘hood. I am expecting both Hekla and Öraefajökull to go Caldera sooner or later in an explosive fashion. Both of those erupt andesites and have the heat transfer rate necessary.

            We could call the VEI-7 eruption 100K events, but they are not really that, they are more common. About once every 10 to 20K. But that is about it.

          • Over the past few centuries, Iceland has had a few explosive VEI6 events (more than 10 cubic km tephra): Hekla 1104, Oraefajokull 1362, Bardarbunga 1477, and probably Vatnaoldur 870. We have had “fatty” VEI6 events such as Hekla 3 eruption, and the Katla and Grimsvotn eruptions around 10000 and 8000 years ago. These eruption has a far larger impact and ash distribution than Hekla 1104, Oraefajokull 1362 or Bardarbunga 1477. And at least Hekla 3 had a significant and long lasting climate impact. There was a large caldera forming eruption from Askja, just before the end of the ice age.

            And then, all of these eruptions are significantly smaller pale with the eruptions that Carl mentioned: the caldera forming eruptions of Krafla, Hofsjokull and Tindfjallajokull. These are likely candidates for VEI7 events in Iceland. But erosion, frequent eruptions, glaciation and new lava/ash layers are so abundant in Iceland that any traces of these would have been quickly erased (except their thick ash deposited in Greenland)!

            And as Carl also said, I also think that eventually one day Hekla and Oraefajokull will have their largest blast forming a caldera, as they are relatively new volcanoes.

            Esjufjoll,Tungnafellsjokull and Kverfjoll also show nice calderas, around 6km wide. We simply know little about their past eruptive history.
            And then you have Snaefellsjokull, which had some nasty and ashy eruptions during the Holocene, at least big VEI5 based in its pumice/ash distrubution and thickness.

      • And Santorini is coughing well………… the whole region around the Aegean is constantly hiccupping with small to medium quakes.

    • But generally you are correct, most very large calderas are around the Pacific, mostly in Andes, Alaska, Kamtchacha Indonesia, New Zealand, Japan, and Phillipines. I think this is where “supervolcanoes” (calderas at least 20km wide) tend to form nearly always.

      However, let’s us not forget obscure Latin American or African large calderas. I am sure Carl could some with suggestions. We could have had some “super-eruptions” at these spots.

      Also, look at hotspots located in continental plates, because these tend to be pressure building and create large eruptions (like Yellowstone and La Garita)

    • I would add Somma volcano to the list of the Caldera volcanoes in Italy. After all, the entire Vesuvius is nested inside of it without even touching the caldera walls…
      And there is a funny fourth cathegory supervolcano that I can’t bend my head around even though I am one of the few who studied it.
      Oku Caldera is one of the largest on the planet, and it is not on either options. No hotspot, no subduction, no rifting… There was probably once a hotspot and a rift there that broke up south america and afrika, but Okus current caldera (120×100) is much later. Relatively speaking it should not exist and be active. Instead it has one of the more active volcanic features on the planet, the rim volcano of Mt Fako. It also sprouts one of the worlds largest CO2 sources (Lake Nyos).

      I would also like to point out that a massive caldera formation under the ocean in many ways could be worse. The Yemenite Green Tuff eruption for instance.

      • It’s too bad the red sea area is infested with pirates (and below the sea). Studying rift volcanology in the Yemen area is kind of impossible due to the dangers of the area, and I can’t even see the volcanoes on google earth since they’re underwater.

        As for researching Volcanoes & Calderas, I would highly highly recommend anybody who hasn’t already, to download global volcanism program overlay for google earth. (see link at bottom to download it, assuming you already have google earth).

        I’m a volcanophile, but I can spend hours on google earth, and it’s always a lot more interesting when the volcanoes are highlighted and you can click to learn the known geological history. It’s also interesting in that you can pretty quickly learn to spot lava flows, caldera systems (including the difference between a subsistence caldera and explosive) and other “generally” interesting aspects of volcanology.

        I also find it interesting spotting extinct volcanoes that aren’t listed in the GVP database. For starters, look up the famous Ngorongo Crater in Africa. Not only is it an absolutely gorgeous Unesco heritage site, widely renowned as one of africa’s best safari preserves, it’s also a nearly circular 22 x 22 km caldera (now extinct).

        Considering the size of the caldera, I have to imagine the original volcano sitting on top prior to eruption was only slightly smaller than Kilimanjaro (at least in width).


    • May i please add Las Canadas Caldera in which Teide stand, 16 x 9 km. because i just came back from a hike through it. ( And shot only 170 photos)

  14. OT:(again)

    Tomorrow smiley turns 30, so congrats 🙂

    And here is archived The 1st published www- page. there still are quite many with similar layout, hmm…

  15. Just watched a TV programme on the Vikings – fearless travellers and adventurers, merchants and warriors – reminded me of someone……………..

  16. I’ve just realised you couldn’t access the whole article I linked to yesterday from New Scientist so here are the bits I was referring to from it:

    ‘Seismic waves travel at different velocities through materials of different densities and temperatures. By timing their arrival at sensors positioned on the surface we could begin to construct a 3D view of what sort of material is where.

    The resulting images are rough and fuzzy, but seem to reveal a complex, dynamic mantle. Most dramatically, successive measurements have exposed two massive piles of very hot, dense thermochemical material sitting at the bottom of the mantle near its boundary with Earth’s molten core. One is under the southern Pacific Ocean, and one beneath Africa. Each is thousands of kilometres across, and above each a superplume of hotter material seems to be rising towards the surface.

    That could explain why the ocean floor in the middle of the southern Pacific lies some 1000 metres above the surrounding undersea topography, another thing plate tectonics has difficulty explaining. Something similar goes for the African plume. “If you go south of the Congo all the way down to southern South Africa, including Madagascar, that whole region is propped up by this superplume,” says White. Seismic imaging reveals smaller plume-like features extending upwards in the upper reaches of the mantle beneath Iceland and Hawaii – perhaps explaining both these islands’ existence and their volcanism. Off the coast of Argentina, meanwhile, the sea floor plunges down almost a kilometre, directly above a mantle region that seismic imaging identifies to be cold and downwelling. And although southern Africa is being propped up by its superplume, smaller hot upwellings and cold downwellings at the top of that plume seem to correspond with local surface topography. The Congo basin, for instance, lies on a cold area and is hundreds of metres lower than its surroundings. “Africa has quite an egg-box shape,” says White.’


    ‘GFZ German Research Centre for Geosciences in Potsdam and his colleagues show how a subducted slab, once it arrives at the boundary between the mantle and the core, can bulldoze material along that layer. When this material meets a thermochemical pile, plumes begin to form above. “We can see plumes developing at more or less the right places,” says Steinberger. For example, their model shows that slabs being subducted beneath the Aleutian Islands near Alaska could trigger a plume beneath Hawaii, creating a hotspot that fuels the Hawaiian volcanoes.’

    It then links to this: http://www.agu.org/pubs/crossref/2012/2011GC003808.shtml

    which seems to be another paywall.

    Sorry about the length of quote…….

    • And the other bit:


      ‘Clint Conrad of the University of Hawaii at Manoa and his colleagues have modelled the effect of a tectonic plate moving one way while the mantle beneath is moving in the other direction. They found that if this “shearing” effect occurs in a region where the mantle varies in density or the overlying plate changes in thickness, it can cause mantle material to melt and rise. This model accurately predicts that volcanic seamounts are present on the west but not the east of the East Pacific Rise, a mid-ocean ridge that runs roughly parallel to the western coast of South America. Seismic measurements indicate that the mantle and the plate to the west are moving in opposite directions; to the east they are not. The model also predicts that the shearing effect is largest under the western US, southern Europe, eastern Australia and Antarctica – all areas of volcanic activity away from plate boundaries.’


      ‘Scripps Institution of Oceanography in La Jolla, California, think they have the answer. Last year they used computer models to argue controversially that the horizontal force exerted by the mushrooming head of the Reunion plume, thought to be the source of the massive outpouring of lava that formed the Deccan Traps in western India about 67 million years ago, sent India on its headlong path’

      All in all I found it a thought-provoking article, but I will stop here…

    • For those who can access the article it is a must read.
      It is by far the most revealing and revolutionizing article I have read in the last 5 years.
      It is full on en par with Carmichaels groundbreaking book on chrystalization and evolution of magmas from 62 and the Mogis original publication, regarding it’s importance. It will change your opinion on how it all works.

      It also kills the theory of impact craters causing hotspots and mantleplumes. I also like this because it closes the loop from subduction to hotspot. So neat, so simple, and so well… beautifull.

      • It also to my mind supports the concept of heat above ground being linked to heat from below, which climatologists won’t consider, but which I wonder about being linked to melting sea ice at the north pole, and the Icelandic hotspot.

        Gravity anomalies may support a wider area of warmer terrain below the North Atlantic, and it would be interesting to have comparative data as to variations of heat and depth below ground, across the globe. To some extent the model on page 10 of the Steinberger-Torsvik also puts paid to the Gulf Stream as the warming influence on the British Isles.

        If Reunion could have erupted so forcefully that it could send India crashing into the Himalayas, then Antarctica may have been propelled similarly ‘quickly’ by an eruption somewhere else.

  17. A bit of idle speculation after reading the supervolcano comment-thread above. Öraefajökull is today the only known active volcano in Öraefajökull volcanic belt, with perhaps the exception of Esjufjöll.
    These are oddballs for Iceland since they erupt andesites and are not really hotspot driven. The are caused by regional melt as that part of iceland dips down.
    The Öraefajökull line continues upwards, but those volcanoes are most likely dead now. What is interesting is that with time the hotspot is going to hit the subduction zone at pretty much the same location as Öraefajökull. Imagine seriously hot basalt hitting the highly fractionalized andesites of Öraefajökull combined with the high watertable? It will be memorable…
    This will of course happen one day, and there is no saying when, that hotspot has a far reach.

    Same also of course goes for Hekla, but she has a different age, a different rhythm, and much weirder way of creating andesites… to say the least!

    • You don´t even have to wait until that point in the future!

      The Icelandic hotspot has a reach of at least 100km in diameter (Oraefajokull is well within the Vatnajokull hotspot influence). Its proximity to the hotspot probably helps in the size and intensity of its eruptions (size: hotspot large volumes of magma / intensity: mix of different magmas and contact with lots of water and ice).

      I read in one paper that the hotspot actually has a much wider reach than just 100km. It has a plume head curved towards the southwest some 400-600km, so it spreads under the dead zone, Hekla, Katla, Tindfjallajokull, Hengill and Reykjanes. So one hotspot pulse will naturally travel southwestwards. Now, we can understand why these rift volcanoes erupt sometimes so large volumes of basalt.

      Hekla and Tindfjallajokull are probably violent because they lie close to the transition to the transform zone. The microplate rotates and results in some local subduction in there.

      The hotspot also spreads northwards as it reaches the surface, towards Askja, Krafla, Theistareyjarbunga.

    • The post was comments from someone from tenerife saying they were feeling stronger vibrations.I was asked to put the heading from the avxan facebook page where these comments were posted which I did .

      • You did, but the text was inelligable.
        And people must be able to read what is written.
        90 percent of what you posted in the comment was in spannish, the translated sentence was gibberish. Nothing missed by removing.
        Also, the content when I read the spannish part was without merrit.

  18. Erroneously discussed old and irrelevant earthquake data from a dataset for the Canaries between 2008 through 2010.
    If you want to discuss old data clearly mark it as old earthquakes to not scare people. /VC

  19. I’m tired….

    I’ve been indexing all the fantastic info presented here on “Large Caldera Structures” and would really like it if ‘yall continued to dig for more info.

    Think of it as crowd sourcing.

    What I’m looking for, is the structure, Lat and Lon if you run across it, the date (thousands of years before present is acceptable), the dominant tephra name (such as Yellow Toba Tuff) and the volume of that tephra… if you run across it. m³ or km³ is fine… I’ll convert. For my fellow US residents, cubic miles will work also. It would also be nice if you could provide a pointer to where the data came from (Wikipedia, Some persons research paper GVP etc.)

    Keep in mind that a lot of these calderas have juvinile structures in them.. I don’t need them, just the largest event. (With the Yellowstone hotspot, it had several parent events separated by millions of years along the Snake River plain)

    If the system has been mentioned in this thread, I already have it and am working on the list. No need to repeat prior work.

    Now…. what I have done so far, is to take the listed systems in this thread, and found a tephra volume for about 12 of them.

    A predominant mechanism for their formation is a piston collapse of the roof. Working off of that, it seems that on average, the floor of the caldera drops about 1.3 km when they happen. The 95% range is 0.5 km to 2.0 km. That’s from 12 samples, so it can be improved upon… and that’s what I’m trying to do.

    This is not a tasking… but if you run across the data in your web travels, I would appreciate a shout here in the Cafe. The end product will be a handy reference for us.


        • I almost missed the fun 🙂
          I thought it was another but smaller swarm so I did almost not even check… almost blew my coffee into the keyboard.
          I have just adjusted my english dictionary accordingly:
          Small = Massive

        • Is there a proper way to define the size of a quake swarm, do you take the mean/median/mode of the quake sizes, and does the duration of the swarm start and end cleanly? Do you take the total joules expended by the swarm to date or between given dates divided by total time as the measure of quake swarm intensity. Could you use something like a hurricane category ? it was a category 3 swarm that continued for 7 weeks, or it was a category 5 swarm that started only one week ago and ended in the eruption of blah?

          • Well, having got myself into trouble over this, I agree – should we go by number of quakes or the size? Or duration? You could have 10 mag 1.0 tremors in a minute – or 20 mag 1.5 tremors spread over an hour. Does 4 a day for a month count as a swarm? It’s a poser!

          • 4 a day for a month over what size area too – if it is inside a 0.5km square then yes I think you have a swarm, over 500km square probably safe to say that’s not a swarm 🙂

          • actually thinking about it a bit more, should the quake swarm be defined as occurring over a volume rather than an area?

            If the minimum number of quakes a day per 0.5km square area for it to be counted as a ‘swarm’ is 4 (for the sake of argument) if you have one quake at 99km depth, and 3 are 10km depth – should that still count as a ‘swarm’ given that the 3 10km quakes are actually 89km away from the 1 other quake.

            should it be defined as a category 1 swarm if a volume of 1 cubic km has for a week
            1 quake of magnitude 1 per day or something like that ?

            category 2 might be
            2 quakes of magnitude 2 per day ?

            so you get a comment like the category 1 swarm at 10km depth for an area 6km by 2km along the fault line at lon lat , has been continuing now for 3 weeks

            or after 10 weeks the category 2 swarm at lonlatdep has now diminished to a cat 1 swarm, but the intensity at lon2lat2dep2 has remained at category 2

            I don’t want to consider a cat 3 swarm
            3 quakes of mag 3 per day in a given 1cubic km for a week – that sounds pretty nasty

            it also makes me wonder if 1 cubic km is the right volume to be looking at ? I was presuming actual cubes btw not a flattened area of that volume which matched the best fit shape to contain the outlying quakes.

            A quake swarm along a fault line might (using the hypothetical system above) be cat 1 along most of the fault and cat 2 at a particular depth and location.

            Is there a real system that defines these anywhere ?

          • No problem with that 🙂 so would you mean
            Sum of Strain release per day in mega joules over a 1km³ volume? How many quakes Do you need to make it trigger?

            Go on Carl/Lurking (or someone else) give us a nice (made up) formula for a volcanocafe category 1 swarm vs a VC category 3 swarm

  20. The swarm was so small that it created a large ghost (3.1M) at a whopping distance, all the way over at Hágöngulón between Vatnajökull and Hofsjökull. Impressive what small swarms can do :mrgreen:

    • Even though Icelanders are used to things moving about, this one probably worried quite a few. This is one of the places that is expected to get a 7M quake sometime “soon”, and with soon I mean somewhere during the next 100 years.
      What we are seeing is a micro-plate twisting about a corner that is locked. It creates several spots where large earthquakes can happen. This particular spot is believed to have 5M as a maximum, but at the opposite upper corner you can have 7M thrust faults, and those are not nice.

      • I was going to comment with a heads up on this swarm but as usual I am too late 😀
        Isn’t it interesting that a few days ago the MAR was active to the south then a few quakes along the rift under Iceand and now this burst of activity in the North?….It’s sort of like a zip fastner!!
        I would like to think each event is linked as a trigger but as I am not really into the physics of the energy etc I am leaving it to A N Other to comment if there is a possible domino effect.

        • It’s very silly – but I am reminded of one of those ‘executive toys’, the one with the row of steel balls suspended from a frame. When you knock one of them, the ball at the other end of the line reacts. I’m sure that Icelandic geology is a lot more complicated though! 😀

          • *whut* Not complicated. Expect so called “ping-pong” effect. Swarms in north (and south) often tend to repeat themselves. I expect similar swarm in S or SW Iceland following this, maybe in a day or two (week), depending which is cause and which is effect.

        • Good morning, Diana!
          In my lay opinion, there is a connection between Reykjanes Ridge’s swarms and Tjornes fracture zone’s.
          I believe in your ‘zip fastner’s’ theory.

          • Although not known to science, I do admit that these swarms often occur at same time in both Reykjanes and Tjornes. However I do have to scratch my head thinking how could that be explained. Because interestingly, we do observe little activity over most of inland Iceland.

            One model idea I had is that there seems to be hotspot pulses beneath Vatnajokull that a few months or years later, affect the surrounding rifting zones. It could have been that a larger pulse from the hotspot is increasing now the activity in both Tjornes and Reykjanes.

            However, we also observed increased activity over Jan Mayen. This is interesting, it is as if all North Atlantic region would be affected. However the rest of the mid Atlantic rift is quite calm, so this process would be regional. Surely this has happened quite often and a I suspect it is not a coincidence, but I do not know. I can´t think of an explaination.

            Please note that it would be impossible for the stress over Reykjanes to pass over to Tjornes while jumping the mainland of Iceland, and not affecting it. But we have seen a calm Iceland mainland in recent days, that is the funny thing.

          • But you know, earthquake swarms occur very often in both Tjornes and Reykjanes, and they do also over other regions, SISZ, Langjokull, Katla, Vatnajokull…. it is quite normal…

            There are much more earthquakes in Iceland than volcanic eruptions!

      • I think Thingvallavatn is the likely spot for a large M7 earthquake. No quakes there for ages, but larger quakes some centuries ago.

        In Tjornes, there were some M6-7 a few decades ago (can´t remember the year, but one in Dalvík, another one close to Husavík), and there have been many swarms since then. I do not think we will see any larger than 4-5 quake in soon. The next M6-7 should occur in a few decades from now, and also some several decades from now we can expect something large again in SISZ. People here don´t worry that much.

        • The last 7M quake was in the 1870s in the fault line coming down from north into Theystareykjarbunga. The revigorated activity is seen as precursor activity for a new large one, but nobody knows when it will come.
          That particular faultline is the only in Iceland that gives Megathrust quakes of the Japanese type.

    • Carl, there was an earthquake at Kverkfjöll before the swarm.
      23:53:49 64.629 -16.672 8.3 km 2.1 99.0 2.6 km WSW of Kverkfjöll
      Could there be any correlation to this ‘ghost’ quake?

    • Sunspots do not trigger volcanoes on Earth.
      This is a widespread hoax, but is simply not true.
      Kate, we cannot believe everything we read in the internet, right?

      Its good to be open minded but also critical.

      We had intensive volcanic activity in Iceland in 1720s and in 1783, that was the period with almost no sunspots on the Sun. In 20th century we had high sunspot activity and volcanic activity in Iceland was very reduced (and also around the world). So that claim is simply no true!

      There is also no correlation between sunspot activity and earthquakes.

      Well, in the remote possibility that solar wind could alter the magmatic processes inside the Earth, then at least the correlation would not be instant and direct. It would take many years and it would be difficult to read. So far, as best as we know, there is no link between solar activity and volcanic/earthquake activity. There is a lot of historical data to show this lack of a link.

      However solar maximum can damage and disrupt satellites. That is well known. However, satellites do survive normal solar storms, as they did in past few years. The largest danger is by far to astronauts.

      Solar maximum might also, in long term, have a correlation with warmer climates (because solar output is larger). We can see this correlation during the Holocene but its complicated, as CO2, oceanic currents, and even cosmic radiation also have correlations with climate.

      “Super storms” can occur in both periods of colder climates as well as with warmer climates. They occur mostly as part of local processes and also regional processes, as oceanic cycles (that do not correlate so well with solar activity).

      Sunspots do not directly trigger weather storms, we can say that, as I have never seen that correlation in my empirical 20 year long weather experience.

      • However tidal processes do affect volcanoes and earthquakes. On Earth theat influence is not so much significant (but earthquakes can occur more often with larger tidal forces). But on the Moon tidal related earthquakes are more significant and regular, and in Io (one of Jupoiter´s moons) volcanic activity is directly caused by extreme tidal forces.
        However, solar activity has no impact in tidal forces, as far as we know.

      • Actually, it is an Urban myth that solar storms destroy satellites. All components are ultra-hardened against radiation due to fear of BMPs under the Cold War. Sofar no satelite since the 1970s have been destroyed by a solar storm. Communication might though go down during the storm itself.

      • There is no evidence of solar storms or sun spot cycle causing earthqiakes or volcanos.
        In regards to weather there is some effect sudden stratosphere warming is one such effect.
        I can go into exactly what happens, but basically to cut it short. Air at very high altitude warms and pushes cold air towards the surface causing disruption to air currents. Also a link to a cooling during periods of low sun spots maunder minimum and dalton minimum. So some effect over a lnog a medium term for weather patterns but nothing ever found for geological effects.The space weather site has good information on particles and plasma from space and coronial mass ejections. I would agree with you that day to day weather nothing noticeable, but over weeks ssw can effect weather pattern and sun spots on very signifigant low cycles may effect climate, But we are talking tens of years of very low sun spots for an effect which is very rare.

  21. Struggling to keep up here.. just a couple of quick things before I have to take the kids out to drum practice:
    1. Re the paper Geolurking linked to from Steinberger and Torsvik: in their equations they state they used a reference gravity of 10 ms-1. I sure hope reference gravity means referenced to the surface otherwise we have another case of Carl’s gob-smackingly simple observation that gravity actually decreases the closer you get to the center of the Earth. Otherwise fascinating stuff and I am only half way into it.

    2. Re Calderas. NZ has had 34 ignimbrite forming eruptions in the last 1.6 million years. Other calderas not included in the list are Kapenga, Maroa, Reporoa, and the biggest of them all Whakamaru. There are probably a number of otherwise that have been since buried by later eruptions. In addition there are probably a number of submarine calderas running up along Kermadecs, some of which were no doubt subaerial eruptions (MacCauley Island, Raoul, etc).

  22. @Lurking
    Nabro and Mallahle,
    I don’t have the size of the calderas – but google maps should give you a decent measure for that.

    Pierre Wiart and Clive Oppenheimer

    A very large eruption or eruptions in the past is evidenced by the presence of extensive ignimbrites, which the authors believe are ‘associated with collapses of both Nabro and Mallahle that formed the present day calderas’ (103). The age of these ignimbrites is unknown, but their spectral characteristics and state of preservation suggest their creation in a single eruptive sequence. The present-day ignimbrites cover an area of ~600 square kilometres, with a bulk volume tentatively estimated at 20 cubic kilometres. Prior to erosion of course a much greater bulk must have been present: the combined ignimbrite outcrop today lies within a 30 km radius of Mallahle, and the authors propose that if there was originally a single ignimbrite sheet extending this distance with a mean thickness of 40 m, the eruption magnitude may have exceeded 100 cubic kilometres (bulk volume)

    incidentally I got that info from http://volcanism.wordpress.com/2011/06/19/a-look-at-nabros-history/

    • just realised that last link has this

      Nabro has an 8 km diameter horseshoe-shaped caldera breached to the SW, and facing the 6 km diameter caldera of Mallahle.

      • Well I just found something I didn’t know that should probably have been obvious

        I was thinking about treating the 8 and 6 km caldera as equivalent to a single different size caldera

        so starting on what is the area of the caldera = Pi R Squared
        I thought 8 squared = 64
        6 squared = 36
        64+36 =100
        sqrt of 100 equals 10

        but then I thought oh – radius not diameter wasn’t sure so I need to start again
        4 sqrd = 16
        3 sqrd = 9
        16+9 =25
        sqrt of 25 equals 5 which was half of the 10 I got before (and for some reason I hadn’t noticed that it was going to be that for sure).

        here’s the badly written explanation if you care 🙂
        sqrt ((2Z)^2 + (2Y)^2 ) = sqrt (4 Z^2 + 4 Y^2 ) = = sqrt (4(Z^2 + Y^2)) = 2 (sqrt ((Z)^2 + (Y)^2 ) should have been obvious to me really

        • For caldera area, I use the area of an ellipse. It’s an approximation, but it’s gonna be closer than a circle, or a simple square.

          A= a*b*π where a and b are one half the semi-major and semi-minor axises.

    • Even the IMO has issued a statement concerning this “small” swarm 😀 Specialist remark as follows:-

      “The earthquake sequence offshore north Iceland continued this morning with a M4.3 at 07:57 and M4.0 at 08:28. Both events have been felt in Siglufjörður, Ólafsfjörður and Sauðárkrókur. Several aftershocks have followed, one of which M3.0. Seismic activity is not unusual in this area, the situation is closely monitored.
      Written by a specialist at 19 Sep 11:11 GMT”

    • Nah, this was much worse in 2008 when the big Sudurlandsskjálftar occurred (2 quakes magn. 6.3 and a lot of afterquakes over 4). This here is just the northern part of Icelandic MAR skifting a bit. And most of the quakes are still rather bad quality. The biggest one was 4,3 magn. It’s a known swarm location between Tjörnes and Kolbeinsey ridge. This part of the MAR is able to produce magn. 7 quakes – but in my opinion it is absolutely unnessary that it shows us that ability right now. 🙂

  23. I’d be happy to help – I suppose I’ll start with info I dug up about the Kyushu (south Japan) Caldera systems.

    Aso Caldera – Kyushu

    Size:10.5 Mi x 15.5 Miles
    Large Caldera Eruption: 90,900 years BP – 600 cu km (372 cu Miles) of airfall tephra and pyroclastic-flow deposits
    Tephra Composition: Basaltic to Dacitic Pyroclastic fall depositis with Calc-Alkaline signature in the more recent caldera forming events.

    Source: http://petrology.oxfordjournals.org/content/39/7/1255.full

    Aira Caldera – Kyushu

    Size: 12 miles x 12 miles
    Large Caldera Eruption: 22,000 years BP – 400 cu km (248 cu Miles)
    Tephra Composition: Rhyolitic

    Source: http://www.agu.org/pubs/crossref/1984/JB089iB10p08485.shtml

    Kikai Caldera – Kyushu

    Size: 12 miles x 10 miles
    Large Caldera Eruption: 6300 years BP – Akahoya eruption – 150 cu km (93 square miles)
    Tephra Composition: Ryholitic

    Source: http://volcano.oregonstate.edu/vwdocs/volc_images/north_asia/kikai/kikai.html

  24. This is actually getting interesting.

    The distance of the inferred floor collapse gets larger the smaller the caldera, based on eruptive volume. I’m up to 16 volcanoes and the 95% range is now 0.67 km – 2.9 km with an average of 1.8 km. (that 95% means the actual average is likely between those two values)

    @Inge B., I did include your Laacher See data, mainly just to see where it fit. I’ll be damned if it didn’t fall right in line with the rest of the data. So, I went and grabbed Pinatubo and Tambora info.

    And for the wandering Nomads who saunter in for a fresh cup of coffee….

    Magma volume, volatile emissions, and stratospheric aerosols from the 1815 eruption of Tambora – Self et al (2004)

    Volcanoes and Tephra of the Japan Area– Machida (2002)

    Click to access 06-2-03.pdf

    But now… time to drive.

    • When I was compiling some of the info for the Aira caldera, one thing I found really interesting (i’ll have to find the source again) was that it mentioned that Aira didn’t collapse in the typical piston-collapse style. Supposedly, the caldera collapsed in a more conical manner, and according to the source, that was common to the southern japan area calderas.

  25. Latest deformation reports from Involcan.

    ,,Recent GPS data processed by INVOLCAN and the Nagoya University researchers show significant changes after the new seismic episode. In the image you can see the evolution in the station located in La Restinga. This has shifted from September 13 1.34 cm horizontally, with a South-East direction and has also promoted 4.81 cm vertical,,


    • Yes IGN have a problem with their link I have just clicked into the link and for some reason it does show EQ’S from 2008 .

        • I did go there first the page that was in front of me was the quakes just for today I had put in the timeframe 19 09 2012 to 19 09 2012 and that was the link I copied from the top of the page.

          Try it for yourself then post the link on here and see what happens.

          • My articulation was not really clear, sorry
            . I meant that you should probably give a time frame in your comment, which can be put in a link I gave, and the link. I know you used it correctly, but ign’s website doesn’t include time info in link’s address, instead it sends a datasheet to server, which then returns the requested data to webpage. Hope this helps;)

    • Thanks!
      Had missed that NASA actually was doing something usefull again.

      Alcubierres solution to “Warp” is slightly different to what I intended, and in it’s initial version about as unlikely as mine. But, if they get the Alcubierre-White Engine to work… Well then we can go to the Stars, and that would be pretty soon. (Like 20 to 50 years).

      • Alderson Drive, not Alcubierre-White Engine one presumes. Larry Niven and Jerry Pournelle registered the TM for that some thirty years ago (see “The Mote In God’s Eye”)

          • Come now, sir! If Arthur C. Clarke can be credited as the inventor of the communications satellite (at least he creduited himself for it), then Niven-Pournelle certainly deserve their accolade.

          • Difference being then that ACC did the drawings for the balloon that became the first experimental comunications satelite.
            For the rest, the first experimental signal sent between two stations via satelite was by bouncing the signal on a gigantic inflated silvercoated aluminium baloon. Ingenious of sorts. And proved the concept.

  26. The reason why the whole Iceland lit up as a Christmas three now and then is because the Common Magmatic Volcanic Pressure Chamber (CMVPC™) underneath the country gets rising pressure from the mantel.

    Note: This theory is from me, and must not be used in any education, because I have no clue about this…

  27. I’ts a kind of weird to watch swedish people making a food program in Finland… in english.

    Nothing really seems to fit quite correctly…

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s