The Usual Suspects and Friday’s NtV Riddle

Photograph by Eggert Norddahl under exclusive right to Volcano Café. Hekla 1980 eruption.

Photograph by Eggert Norddahl under exclusive right to Volcano Café. Hekla 1980 eruption.

We are minutely studying any hiccup from the Icelandic Usual Suspects. In the case of earthquakes we are quite used in getting all sorts of useful stuff out of them. One of my favorite ways of studying earthquakes in volcanoes is the cumulative seismic release (CSR). In the case of Grimsvötn it might even be the perfect way of predicting how close he is to erupting. Except for Hekla the Icelandic volcanoes are rather noisy, but how noisy is a volcano in the making?

I had this question ringing in my head yesterday so I tallied up the sums for Iceland’s only known proto-volcano, the Gódabunga cryptodome. A cryptodome is a magmatic emplacement that is unerupted; it is a magmatic system in the making. Normally it suffers several magmatic emplacements before erupting, but most often a cryptodome never erupts. The reason for them not erupting is that it takes a tremendous amount of energy and pressure for a volcanic opening to form. These virgin territory emplacements are hideously noisy compared to a regular volcano.

I had handy data for Eyjafjallajökull, Gódabunga, Grimsvötn, Hekla, Katla and Torfajökull. I discarded Hekla since it would not even show as a speed bump compared to the others. In the end the results got interesting.

The data is from July 1991 up to February 2013 except for Grimsvötn (1996). Energy is in Joules, as a comparison one could use a Big Mac; at 540 kilocalories it has 2.2 million Joules of energy (roughly equivalent to a 1.1M earthquake).


Photograph by Eggert Norddahl under exclusive agreement to Volcano Café. Eyjafjallajökull eruption 2010.

Photograph by Eggert Norddahl under exclusive agreement to Volcano Café. Eyjafjallajökull eruption 2010.

Eyjafjallajökull was rather active before the eruption in 2010, the total CSR was 6.8e+9 and otherwise Eyjafjallajökull was rather quiet during the period. The total tally including the VEI-4 eruption during the period was 1.06e+10. As you will notice this is surprisingly little. Let us now walk over to the quiet neighbor to the north. After the eruption this volcano has been very quiet.


Torfajökull, the forgotten and quietly playing volcano.

Torfajökull, the forgotten and quietly playing volcano.

This volcano latest erupted in 1477 and has since then not erupted, but it is still active. It suffers from two opposite forms of earthquakes. It simultaneously has earthquakes associated with cooling magma, and earthquakes associated with magmatic emplacement. It is probably safe to assume that this large volcano has more than one chamber, and that the most likely spot for an eruption will not be at the same place as the last one.

It would therefore have been interesting to have these earthquakes separated, so we could compare. But alas, we do not have that. The total sum during the same time period is 4.8e+9. Except for 2010 Torfajökull had higher CSR then Eyjafjallajökull during the entire period.


Photograph by Eggert Norddahl under exclusive agreement to Volcano Café. Grimsvötn 2011 eruption, sun over ash cloud.

Photograph by Eggert Norddahl under exclusive agreement to Volcano Café. Grimsvötn 2011 eruption, sun over ash cloud.

For being a very large volcano Grimsvötn is surprisingly quiet. The earthquakes during the period from 1996 are rather even over the years, with the only exception being
the period after the 2011 eruption where the volcano has been very quiet.

Grimsvötn seems to erupt as soon as it has reached a certain value of CSR. At least it did that the last two times in 2004 and 2011. That value is slightly more than 3.8e+9. The total strain release between 1996 and now is 7.7+9e, or slightly more than Eyjafjalla released in the 3 months before erupting up to the end of the eruption. Who thought Grimsvötn would be the shy quiet one?


I guess nobody will be surprised that Katla is a noisy volcano. It suffers from numerous small to medium sized earthquake swarms. Many of those are signs of magma entering the system. The noisiest year was 2011-2012 when the volcano suffered from a CSR of 8.9e+9. During the entire time the CSR was 3.1e+10. Now, let us go and visit the noisy unborn baby volcano next door.


Gódabunga Núnatak next to the SIL station.

Gódabunga Núnatak next to the SIL station.

Gódabunga was a quiet unassuming little Núnatak (cliff protruding above a glacier) just on the outside of the caldera wall of the massive Katla volcano when, to the surprise of everyone, it started kicking around. In 96-97 it had a CSR of 1.8e+9 and most thought it was Katla having a side emplacement. The next year it got a CSR of 6.5e+9 and it was noticed that the hypocenter of the earthquake ball was outside the Katla system. It caused a bit of a stir; remember that all of a sudden out of the blue there was more CSR than Grimsvötn produces during the entire run up to an eruption.

For two years it was showing signs of calming down after the initial emplacement. Gódabunga seemed destined to dwindle into the mist of magmatic emplacement history, the same way 99 percent of all emplacements go.

After the two years Gódabunga went on a massive spree of large emplacements that really knocked on the roof of the teenage room.  During the next five years it had at least two more even larger emplacements than the initial one. The CSR for the period was 6.03e+10 with the record year (2002-2003) blasting an impressive CSR of 1.83e+10.

After those five years Gódabunga has calmed down, but the CSR is still 100 times higher than before the commotion started. The total release during the period is a whopping 9.02e+10.

What will happen to Gódabunga is written in the stars so far. Remember that science have never seen a large new volcano blast into life, especially never with instrumentation like this. The ones science has seen have been rather small, and they have been un-instrumented. If Gódabunga ever is born we only know one thing, it will be very noisy.


For those who are surprised over how quiet Grimsvötn is should remember that this volcano is erupting often. The system is permanently heated and filled with magma, so the roof over the chambers cannot withstand a lot of pressure. One should also note that the earthquakes in a volcanic system are a sign of pressure increase (or in some cases of pressure decrease as magma cools down and contracts). So, Grimsvötn will show comparatively few earthquakes before erupting since it cannot take a lot of pounding.

The fact that Grimsvötn has a weak top is what makes CSR into a good predictive tool. The amount of pressure increase the roof can take will be about the same between the eruptions. At least for as long as the eruptive cycles have roughly the same time spans.

As the roofs above volcanoes cool down it will take more and more pressure for a volcano to break through. Also size and depth of the magma chambers are factors that affect the amount of pressure needed for an eruption to occur.

Eyjafjallajökull had a rather small magmatic system that was fairly close to the surface (after an emplacement just before the period my data covers), so it had a surprisingly small conflagration of earthquakes before erupting.

Katla has not erupted since 1918, and has a very large magma system. So the roof has had time to solidify and can due to the size flex quite a lot over time. So, it is not that surprising that it can withstand a lot of CSR over time.

Gódabunga on the other hand has an unknown size of the magmatic system, but one thing is clear, it is fairly deep down, and the roof is (no pun) rock hard. Here the magma has to quite literally pound its way through layer after layer of hard old rock so naturally there is a lot of music being played. How much more pressure will it take before an eruption occurs? The answer is that nobody knows. All we can do is waiting for a new emplacement and then try to track the progress of the earthquake ball hypocenter upwards. For all we know it could withstand anywhere up to ten times as much CSR, especially if it is temporally well spaced.

Numbers taken from Icelandic Met Office and treated by Carl, then made into a plot by GeoLurking.

Numbers taken from Icelandic Met Office and treated by Carl, then made into a plot by GeoLurking.

If the CSR is a representation of the systemic pressure inside an unborn volcano, the Gódabunga is potentially a bad one. If we compare with El Hierro that had an eruption after a long repose time and had a very noisy eruption the energy released there was still 1 000 times less. In the end we are faced with the small thing that the CSR are caused by a magma emplacement, and the amount of activity gives a hint of the amount of magma emplaced.


Name those Volcanoes Riddle

 1 point for each Volcano …

No 1 – Legendary lost home of the hairy eared dwarves? SOLVED Mount Shasta 1 point Sa’ke

No 2 – 4295 eponymous deposit. SOLVED Katla / Vedde Ash

No 3 – Thoroughly well bred parent of the US Ambassador? SOLVED Acatenango 1 point KarenZ

No 4 – Slightly under 50 miles north of a pillar of salt. SOLVED Aukland volcanic field 1 point KarenZ

No 5 – Its location and summit hold a global distance record.  SOLVED Chimborazo 1 point Sa’ke

No 6 – Site of the earth’s nastiest outside loo. SOLVED Mount Elbrus 1 point Alison


355 thoughts on “The Usual Suspects and Friday’s NtV Riddle

  1. Ben Macdui in Scottland… 4295 feet.
    Volcan de Ipala, also 4295 feet (guatemala)
    Lagoon Colorada on the Altiplano at 4295 meters with its volcanic origin borax island deposits. Lagoon Colorada is a salt brine lake in the worlds largest salt lakebed.
    The volcano then is the Puna Volcanic Complex.

      • Well, that was all height related volcanic features on the planet…
        It costs 4295$ dollars to climb Arenal… But that’s not it.

        • McCoy Canyon Flow… Columbia River Basalt Group. cirka 4295 cubic kilometers of lava…

          But, I will go with the Gobi Dessert with its interesting volcanic origin. Specifically Oyuu Tolgoi gold and copper deposits.

            • Still not on the right track … but with every comment I am learning more miscellaneous facts … grinning

            • I give up on anything 4295 related…
              The only volcano related thing I could find timewhise was a nutter trying to prove that the biblical Noahs Flood was 4295 BP by using greenland drillcores…

              42 Molybdenum in 95 Americium (America), then we are at Quetza caldera, famous for its Molybdenium porphyry deposits.

  2. OK let me gently lead you in the right direction …

    4295 directly links to a place that has lent its name to a particular volcanic deposit …

    • Problem is that however I google-fu I only get Noahs Ark… According to legend that one stranded on Ararat,,,,
      Ararat is famous for its Ararat deposit that contains gold/silver/copper…
      But I will go for the arch being the deposit…

      I know this is so horribly wrong…

      So… Tephra – Minoan deposit – Thira/Santorini.
      Lahar – Pinatubo
      Pyroclastic flow – mount Pelée – Peleian eruption.
      Deccan traps…


      • Loving this …
        Perhaps coming at the riddle from the other direction might help … so we are obviously looking for a deposit that is irrevocably linked to one volcano … and this deposit is named after a place linked to 4295 …

  3. Evenin’ All,
    Haven’t been around for a while… (don’t ask… family schtuff…)
    I’ve caught up, and then I got to thinkin’
    Sometimes only a foreign word will do; in this case krummholz…
    I guess we are all familiar with the concept of the treeline ( above a certain altitude trees will not survive; this depends on where in the world you are and local conditions…)
    Krummholz (apologies german schpeakers) refers to that zone at the upper margins of the treeline before the saxifrages (rockbreakers) and other true alpines take over…
    The krummholz is where natural bonsais are found; pioneers for their species and sculpted by the “uncomfortable” conditions…
    I’ve hiked in a few situations where the trees go from towering to knee high within a hundred metres of ascent…
    I know how Gulliver felt…

        • I’d like that … and maybe you could read the recent comments above and solve clue No2 for me … smiling sweetly …

  4. Grimsvötn Saksunarvatn Tephra Layer…
    Agnano Pomici Principali tephra, Camping Flagrant Caldera (original site for the first named pumice deposit, most likely I think)
    Heimaey, Hain Tuff Ring.. (not likely)

    • 🙂 amusing, not joining in on trying, no.
      Those English speaking riddels are not for my humble foggy mind. Never good at chemistry, think only passed basic 101 … that one with the system that had Fe in it … but volcano rocks simply elude me (english wise atrt least).
      + as you see, survived first week of remobilishing activities … 🙂

        • Yes, I noticed, nothing blew in Iceland last week, not even Hekla stirred… piddly small one in Vatnafjöll, shows area is active.. but nice one in Russia (?) or Alaska did.
          Anyways its weekend dalek and anything can happen then. Last two out of three eruptions here were on … Saturdays! (Fimm and Grimsvötn) So I figuread anything can happen, using “dog logic” (isl. Hundalógic):
          2010 2 eruptions (Fimm and Eyjo were same but also separate)
          2011 1 eruption (Grimsvötn)
          2012 0 eruptions
          2013 ? most likely none of abowe numbers ( so three or more, yieks? )

          • Nah, you missed the pattern… 2, 1, 0… so 2013 will be the first ever negative eruption!
            We will see Hromundartindi being sucked down into one of Lurkings Holes. 🙂

    • Really fishing now… Askja Ash deposit from the first preserved Askja eruption, can’t be more eponymous than having an ash deposit at Askja volcano…
      And here I give up…

  5. Here is a video that fits in here on a friday evening, it’s title is also what Kilgharah has made my poor brain do…

  6. Mount Eolus – you have no idea how hard it is to scrabble around for clues when I’m so far behind 🙂 will keep fishing.

    • The Eolus Granite of the Needle Mountains of southwest Colorado intrudes a cover sequence deposited during Mazatzal orogenesis and a sequence of amphibolite facies gneisses, which form the basement.

      • Eolus was for no.2 by the way. No. 4 might be Dallol volcano? I havent had chance to read through the previous answers yet so don’t know what’s been said already.

    • Nice to be missed. I recently got a new job next to my normal work as staff council and member of the board. This means lots of meetings and the urgent need to be well prepared for those meetings especially since i knew very little about work laws. ( And tactics and and and… i was never and will never be good at politics)
      Which leads to reason number 2 of my absence.. i often much rather do gardening to relax and calm down after major discussions.
      And my kids..
      Anyway, i am and have always been around every day since i was made a dragon over a year ago, i am just quietly munching spam.

  7. No 4: Aukland volcanic field. The pillar of salt is Lot’s Wife, which is a crater on White Island. White Island is close to 50 miles south of Aukland (and a bit to the east).

  8. Carl … before I disappear (very late) to a party … is Vedde Ash associated with Katla or Askja?
    As you well know I am no expert and rely on research to set the riddle each week … have I screwed up big time … and if so will you forgive me for your brain ache … smiling sweetly!

    • Not definite, but likely; cf. below and many other papers:

      Click to access Menzies_resume_7_.pdf

      “The Vedde Ash is a bimodal rhyolitic (clear shards) and basaltic (brown shards) tephra layer believed to have been erupted from the Katla volcano in Southern Iceland (Lacasse
      et al., 1995).”

      (Fleeting visit – UKViggen in UK for one evening only – has been a CZViggen for a few days and tomorrow will become a CHViggen for a week)

      PS if you want to see a manly volcano doing manly things watch Shiveluch for a bit. Has been splendidly Baad-Assss the last week. Six or seven explosions a day with rockfall. All fed by block extrusion and even some incandescent lava last night. Not so explosive but very steamy today!!!

    • Sometimes I even have the horrible feeling that the Vedde ash consists of both ashes.
      Remember that this was during the Icelandic flare up due to deglasiation pressure release. Loads of volcanoes was active at this time. Separating one of them is fairly impossble.
      One should though remember that Askjas eruption was much ashier then Katlas.

      I think we would have to call this one insolvable untill I get my greedy fingers on a sample of Vedde ash to check for REM prints. (and a sample of Askjas ash, and a sample of Katlas…)

      • Agreed … Katla and Askja shall officially have joint claims to the origins of Vedde Ash and I declare the clue unsolvable until you get your ‘sticky mitts’ on some samples!

  9. So you all know about Mount Shasta that hasta. Being the railfan that I am Mt Shasta lies just east of the Old Southern Pacific railroad while slightly just to the West is the Black Butte Volcano. The railroad run runs right thru them.on the hencely name Shasta Subdivision. Wonderful route.

  10. As expected… a royal goat-rope. Ganged switch, a forever O/S load time. Network Op center can’t see it, but can see the servers on the other side. Turns out, when they configured it, they never put in an IP for the interface. So, console in to finish up what should have been done before it was sent. Guy I’m with cant hit it with his laptop, try mine, find out my usb com port is in my other bag (124 miles away), but I do have the driver disk for it. He doesnt have the driver for his. Frustrated, grab a PC and drop PuTTY on a thumb drive and hook up and configure. NetOps keeps calling back to have us move ports around for the servers. (stuff has to be in specific port for the security protocol, unused port get disabled afterwards.)

    • So, here I sit, in a cheezy motel, head throbbing. No time to read about caldera formation dynamics… as was my plan. WiFi is free, but I’d be risking packet sniffing If I used it.

      BTW, Germany told Justin Beiber to come get his damn monkey… and to bring his checkbook. Quarantine ain’t free.

      • And in Sweden Justifer Bieblon is facing a criminal investigation for drug charges… Something tells me that Europe will be safe for the Twirp for a long time.

        • “safe for?”

          By all means, please keep him. Maybe toss a bit of rouge and a party dress on him and put him to work.

          Load him up with tatoos and you can use him as a diplomatic envoy. North Korea would be my reccomendation.

          • Well… He has the same hairdresser as Kim Jong-Un…

            Nah, I think we could live without him. But he will probably never return since he would then be put into custody for interogation.

  11. There was an earthquake in Japan near the coast of Fukushima. Stated as Mag 5,9 , GFZ has it as 6.0.
    This reminded me of bringing up a question. during the events around Fukushima Daichi the had shortly mentioned that there was a second atomic powerplant closeby which was also affected by the Tsunami. Fukushima Daini. I just read in the list of Japanese atomic power plants cold shutdown. The Wikipedia link is
    One can read in this article:The design basis accident for an earthquake was between 0.42 g (4.15 m/s2) and 0.52 g (5.12 m/s2) and for a tsunami was 5.2 m.
    Would an earthquake Mag. 6 have been a problem for the plant if it had not already been shut down?
    Anyone knows more details about what happened to this second Fukushima plant?

    • The Wikipedia ariticle says, that Tepco wanted to release the remaining 7000 tons of seawater back into the sea in July 2011 since the reservoirs holding it back started corroding but did not get permission to do so. Now it is more than 2 years later… what happened to the water till 2011?

    • Without checking the specifics regarding the water.

      But, the powerplants are well able to take a 6M earthquake, the japanese ones are also actually secondarilly strengthened against earthquakes above any other powerplants on earth.
      Problem was that they where not built for the 9.4M earthquake that hit Fukushima. Nothing in the end is built to take that. Problem is that the japanese plants should all have been on the other coastline for safety reasons.
      In the end a nuclear powerplant should not be built in an area like that where you have had numerous historical ultralarge earthquakes. And… One should not build them at all since they do time and again release crap. Even when there is no accident the mining is poisonous enough. Blekh!

        • The most shocking thing I learned while I worked in the power utility business was that there has never been even 1 kilowatt of energy produced from a nuclear powerplant that was giving profit.
          So it is not only ecologically insane, it is also economically a fools game. The entire concept is a cold war relic that has gotten out of hand. The heavily industrialized nations wanted them to make nukes and to show off. And now the third world countries have taken after since they also see it as a step of advancement (both nukes and showing off). Only reason for most countries to have them is to make nukes. Japan is different though, they actually are the only country on the planet that really need them for energy production, but every kilowatt produced are subsidized there.

          And the list of near misses and small accidents is enormous. The systems are just too complex to manage safely whatever one does to run them safely. After one year being a part of running 12 reactors (later 21) I started hating them. They made me into a green muppet more efficiently than anything else. This from a guy who seriously think that blowing a large hole in the ground (mines) is a good and necessary idea.

          When we in 10 or 20 years can do a tally of what Fukushima did, we will still do not even see the end of the death toll. It was so messy that people do not understand. It was much much worse than all other accidents we have seen combined. I have seen figures that show that the Fukushima failure produced as much radioactive material dispersal as all nuclear weapons detonated together.
          Let me rephrase this, I am a physicist, I have worked with particle physics and nuclear powerplants for years. I know more than almost anyone on the planet. I would not move to Japan due to health concerns, and I would not ever even visit the province that Fukushima is situated in. Ponder that one.

  12. Somewhat belated for the riddles and no time for ruminations…:( The trouble with working at home is that there is really no cut off/time to go home/ end of working day siren.
    I am snowed under with work, which is financially good but it’s hard to juggle making lemon drizzle cake, Swedish meatballs in sauce, doing the laundry and taking accurate, clear and detailed photos. Not to mention head to heads with certain programs that I need to use. GRRRRR!
    To rub salt into the wound, yesterday, during an interview with the new young bank manager I was treated to a perfect example of condescending stereotyping of Ladies sporting wrinkles and a walking stick…..
    I had politely explained I would not use online banking as I consider it to be unsecure. ( He was also trying to get me roped into a funeral plan. His recitation of the sales patter he had learned was intriguing, obviously created by a 30 something who’s expectation of a sizeable inheritance was close to his heart)
    ” I understand your fear of on Line Banking Mrs Barnes. However I suggest that you buy a lap Top and get one of your family to teach you how to use it. You will find it much easier than trailing in here every month to pay your bills”.
    The poor lad didn’t know what had hit him. He was lucky it was only a verbal assault!
    My parting shot was…. “Someone, somewhere will dispose of my mortal remains when I snuff it. I intend to spend and enjoy the money I have worked for. I may get that smart TV after all !”

      • Lol tgmccoy. I like it. 🙂
        The old prop airplanes were majestic. I have a photo of me a few years ago ( :D) standing by an aircraft wheel at The Farnborough Airshow. I think is was a wheel on the Bristol Brabazon. I remember seeing, or rather ,hearing that plane. It was huge and very loud. I will try to find it and get it on line. The photo I mean 😀

    • ROFL!
      You should make him a friend on Facebook and invite him here to read your morning ruminations. There are after all quite a vocal crowd in here who could teach him a lot on how to use computers since he is so young… I am fairly certain that I in my early forties is both among the youngest, and one of the least computer savvy…
      My mother is 80, and she is making (with my blessing) dead certain that there will be no inheritance by travelling around the globe drinking anything that floats. She prefer to go to places like Ibiza since that is the only place where she finds people who can party that hard… Normaly the between 18 and 25 is broken down after a week around my mother and need a liver transplant.
      I wholeheartedly support my mother in her campaign to have as much fun as possible between retirement (she was a steadfast school teacher) and her last day. She has by far earned that right.

  13. An interesting photo ©Yuri Demyanchuk showing the Tolbachik lava front two days ago.

    Apparently forest fires are a concern, although no threat at the moment. At first glance it looks like grass, but then you realise it is trees, giving a good scale to the size of the flow.

  14. Today is the 33 year anniversary of the Mount ST Helens eruption.. The May 18 eruption. Composite photograph from 35 miles (60 km) west in Toledo, Washington. The ash-cloud stem is 10 miles (16 km) wide, and the mushroom top is 40 miles (64 km) wide and 15 miles (24 km) high. The footprint of the cloud stem is roughly the same as the devastated area north of the mountain where the forest was knocked down and which three decades later is still relatively barren.

  15. Arg, i was looking for a topic to write about this afternoon. Now Mount Saint Helens .. that would have been a worthy topic.
    Anyway, in agreement with Carl i made a small post out of my question about Fukushima Daini
    New post is up!

  16. I know that I’m going back to the The Usual Suspects article, Hekla is on the verge of Eruption, Earthquakes and Emplacements going on at Godabunga, Katla, Torfajokull, Activity again at Grimsvotn, Bardabunga, anything else?

    • You forgot Krisuvik and Theistareykjarbunga…
      Krisuvik is buildiing up to a potential eruption. It could be anywhere from a month to ten years away.
      Theistareykjarbunga seems to be slowly inflating 2,5cm per year without showing any large increase in systemic pressure. The reason for this is probably the size of the magmatic system being very large. Something that is substantiated from the very large eruptions that Theistarekjarbunga has suffered from historically (largest in Icelandic history with more then 30 cubic kilometers of lava in one go).
      It is currently showing about 1 earthquake per week, and that amount would need to go up before pressure has risen enough for there even being a risk for quake swarms to occur. My guess the pure size of the system would mean that it will take at least 10 years (probably towards 100 years) before the pressure is enough for an eruption to occur.

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