Reply to: “Ice cap thaw may awaken Icelandic volcanoes”

Guest post by Steven Goddard

Smoke from a subglacial volcanic eruption rises above the Vatnajökull ice cap (photo by Oddur Sigurdsson) Image via Ben Orlove, UC Davis, click for his page.

Scientific American has reported that global warming may cause an increase in volcanic eruptions, due to increased magma formation at lower pressures as glaciers melt.

This caught my attention because I used to work as a volcano researcher and igneous petrologist.

That report said that about 10 percent of Iceland’s biggest ice cap, Vatnajokull, has melted since 1890 and the land nearby was rising about 25 millimetres (0.98 inch) a year, bringing shifts in geological stresses.

They estimated that the thaw had led to the formation of 1.4 cubic km (0.3 cubic mile) of magma deep below ground over the past century.

At high pressures such as under an ice cap, they reckon that rocks cannot expand to turn into liquid magma even if they are hot enough. “As the ice melts the rock can melt because the pressure decreases,” she said. Sigmundsson said that monitoring of the Vatnajokull volcano since 2008 suggested that the 2008 estimate for magma generation was “probably a minimum estimate. It can be somewhat larger.”

Interesting theory, but does it work quantitatively?  Magmas, as with most solids, do show a direct relationship between the melting point and pressure. As the pressure increases, so does the melting point.  (Ice is a noticeable exception to this, and shows an  inverse relationship.  The reason that people can ice skate is because the pressure under the blade creates a thin later of melted ice which lubricates the surface.

Below is a phase diagram of a basaltic magma similar to that found in Iceland, showing the relationship between temperature and pressure.  The melting temperature does decrease at lower pressures.  From 100 km depth to 0 km the melting point drops about 300°C.  That is about 3°C / km.  Ice is about one third as dense as basaltic magma, so the loss of 1 km of ice lowers the melting point by about 1C, or less than 0.1%.

http://faculty.plattsburgh.edu/mary.rodentice/courses/petrolpresent/Ch%2010%20Magma%20Generation%20’07.pdf

More precisely, this study from the Carnegie Geophysical Institute did an empirical measurement of the relationship for one basaltic mineral – diposide. They found the relationship to be

Tm = 1391.5 + 0.01297 * P

Where Tm is the melting point in degrees C and P is the pressure in atmospheres.  One atmosphere pressure is equal to about 10 metres of ice, so one additional metre of ice increases the melting point by about 0.0013°C.  The loss of 100 metres of ice would therefore lower the melting point by about one tenth of a degree.  The thickest ice in Iceland is only 500 meters thick, so complete loss of all ice would only alter the melting point by about 0.5°C, or less than 0.05%.

The geothermal gradient of the earth is typically about 40°C per km, so a 0.5°C change in temperature is equivalent to a depth change of about 20 metres.  Near mid-ocean ridges this gradient is steeper, so the equivalent depth change in Iceland would be less than 20 metres.  Is it credible that a 0.5°C decrease in the melting point could stimulate excess volcanic activity?  Short answer – no. Volcanic activity is caused by magma rising to the surface, not glaciers melting.  However, the loss of the glaciers would reduce the amount of steam and ash generated.  Ash is formed when magma is cooled and fractured by steam.  So the loss of the glaciers would reduce the size of the steam/ash cloud and make the Iceland volcanoes behave more like Hawaii volcanoes.

In short, the loss of all ice in Iceland would make the volcanoes less destructive.

BTW – On Al Gore’s planet, the geothermal gradient is much higher, with core temperatures averaging millions of degrees.

http://www.youtube.com/watch?v=ag2AWst3Qv4


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164 thoughts on “Reply to: “Ice cap thaw may awaken Icelandic volcanoes”

  1. So, you admit, that if Gore is correct, we may have reached a tipping point?

    Great last line. And very interesting analysis. Can the guy who was quoted on this scary story possibly not know this?

  2. The economic damage now being inflicted by the
    volcano ash upon the British and European economies
    appears to be on a scale equivalent to the
    economic damage recently inflicted upon Iceland
    by the activities of UK and Europe.
    This is simply a non-judgmental observation
    unrelated to any karma or other
    introspection.

  3. I’m not sure melting point has a lot to do with it.

    An eruption is caused by a molten or semi-molten blob of magma that has a lower density than the surrounding rock. As a result it rises and either intrudes into the country rock – creating dykes – or burst onto the surface creating different volcano forms depending on the chemical composition of the magma. In all cases it intrudes through already solid rock

    Basaltic (basic) magmas are very fluid and have a lower melting point – hence they flow easily with long flat cone shapes.

    Acidic magmas (high in SiO2) tend to produce smaller steeper cones as they freeze much more quickly.

    Depending on the amount of ground water the magma passes through you get different effects such as cinder cones.

    If you get a really energetic magma ball rising it can rise at incredible speed and create continent wide destruction from the resulting high energy release on hitting the surface – coming soon to a Yellowstone National Park near you.

  4. If the theory were true, then the MWP would show us to have been awash in volcanoes, right?

    I’m awaiting the pronouncement that the cooling resulting from this eruption will be more severe due to global warming. In fact, the cooling will not only be more severe, but will last longer as further testament to global warming.

    –“Global Warming….We don’t make the weather, we make the weather worse”

  5. Setting on several cubic meters of Columbia River Basalt, I know that this
    Basaltic flow lasted a very long time. Basaltic Volcanoes seem to cook on and on
    and this isn’t good for the rest of the northern hemisphere..

  6. DJ Meredith (20:21:43) :
    If the theory were true, then the MWP would show us to have been awash in volcanoes, right?
    =====
    Maybe, unless the MWP wasn’t very W.

  7. “The fact is that we can’t account for the lack of warming at the moment and
    it is a travesty that we can’t.” Trenberth to Mann, ClimateGate email:
    =================================================
    I’VE CRACKED THE CODE. What Tranberth was really saying was:

    ‘…….it’s a shame that we’ve taken this model and put lipstick on her, added a bit of plastic surgery, corsett to take away the MWP, implanted a Dolly Parton sized peak at the end to make her look scarily hotter……….and she turns out to be a Transvestite????!!!!…’

  8. After a warm start to spring, reaching as high as 90 degrees F, I woke up today to 2 inches of snow on my deck here in New Hampshire, with a promise of more snow this evening when temps go back below freezing. My first thought was, OMG, global cooling already from the volcano?

    Temps according to local weathermen are 20 degrees below normal. What do the alarmists claim it is here?

  9. Using that logic, regions that are still experiencing uplift from the removal of the Pleistocence icecaps should have been a focus for volcanic eruptions as well……..This isn’t science at all but plain geological baloney. But if SA supports AGW, then the editorial brains seem to have been transformed into a special type of baloney.

  10. I’m sorry Steven, but I felt compelled to post this…

    “The top layer of the ice is really a ‘quasi-fluid’
    This is the true reason why ice is slippery. It has to do with the properties of water when it forms ice, and it is a relatively recent discovery. When they turn to a solid, water molecules link up in hexagonal patterns (because they are polarized and can form hydrogen bonds), and these hexagons form large sheets … layer upon layer of sheets. The molecules inside a sheet are attracted to each other more strongly than to molecules in the sheets above and below. This means that the sheets can easily slide back and forth relative to the sheets above and below. A small sideways force from a skate will cause these layered sheets to slide, acting just like rollers on a conveyor belt.
    Another property of ice is that the molecules on the surface are more attracted to things passing over it than they are to the other molecules of ice on the surface. The unfilled bonds of the surface molecules can grab at anything that comes near … like your foot … and be pulled out of the surface of the ice. Once they become detached they can ‘roll around’ on the surface of the ice like tiny ball bearings, making the surface slippery. ”

    http://www.worsleyschool.net/science/files/myth/myth.html

    :)

  11. Nice, Steve. Far as I have been able to figure out, increased volcanic activity rates are coincidental with low solar activity. It never occured to me that ice melting would make for extra ash. A very long period of low solar activity making for increased vulcansim in cooler/wetter times would be it’s own mechanism to further drive down temps.
    It would also give rise to a possible explanation for C02 lagging.

  12. Mean while the Greens belive the shut down in European air traffic has saved the world tonnes of C02,…but….

    Stranded folks don’t tend to stay that way, there’s rail, and buses and cars and all manner of carbonising gadgetry that can move Body A to Location B.

    They’re just slower, and lower than a dreamliner, hell they could even take a ferry, or a gypsy’s caravan. Segways are in…

    The danger this erruption poses, it seems, is to common sense. Kudos to you sir, Steven Goddard, another cogent, well articulated article.

    I abandoned New Scientist and Scientific American a year ago, I can learn more here, thanks to Antony Watts, than in any glossy covered, photo-shopped, periodical.

    National Geographic,…you’re on notice too…

  13. Looking at the picture of the venting volcano above it seems clear that volcanic activity is a driver of climate change that we must take very seriously. While we don’t know when, it is just a matter of time before a very large volcanic eruption, or possibly a cluster of big ones, causes an episode of rapid cooling like the year without summer:

    http://en.wikipedia.org/wiki/Year_Without_a_Summer

    We are very unprepared for this type scenario. Shouldn’t we be diverting some of our limited resources, including some of our good climate scientists, over to researching and preparing for an inevitable rapid catastrophic volcanic cooling episode? Solar panels aren’t going to be much help when millions of people are starving to death due to crop failures…

  14. rbateman – And won’t all this extra ash, especially if this continues, eventually fall out on glaciers and ice caps, absorb heat, and speed up their melting?

    That would make the AGW gang happy.

  15. Thank you!
    Talk about smacking someone right back into their place. When I read that less ice would increase magma I knew they had completely lost their minds. Now Scientific American is no better than some third rate rag. mag.

  16. I can see a reason for diverting aircraft around Iceland because of the potential for engine damage, but shutting down all air traffic over northern Europe seems an over reaction.

    I suspect this is the air transportation version of the precautionary principle.

  17. The analysis in this post has to do with pressures, melting points, and up and down motion. In addition to the numbers provided one might also consider the location at a divergent boundary and look at the spreading numbers. I think this region is going to have eruptions, with or without ice, until the Mid-Atlantic Ridge cools off, locks up tight, and sinks into the abyss.

    http://pubs.usgs.gov/gip/dynamic/understanding.html

    Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle. Picture two giant conveyor belts, facing each other but slowly moving in opposite directions as they transport newly formed oceanic crust away from the ridge crest. [With map of Iceland in context.]

  18. The S.A. article is total nonsense. The Icelandic volcanoes are in rift zones along an extension of the mid-Atlantic ridge. The crust is separating to the east and west at about the speed at which fingernails grow. Glacial ice doesn’t change that speed whether it melts or not. When the crack widens enough, basalt flows out. It’s that simple.

  19. Typo in the article:

    “The geothermal gradient of the earth is typically about 40°C per km”

    should read :

    “The geothermal gradient of the earth is typically about 25°C per km, or 1°C per 40 metres”

    The calculations which follow were done with the correct numbers.

  20. Steve says “This caught my attention because I used to work as a volcano researcher and igneous petrologist.”

    hmmmm….my next book will be a romantic novel about a traveling volcanologist named Steve who is called in to calm the nerves of jittery EU air travelers….I’m thinking of calling it “Return to Reykjavík”.

    Nice job, Steve, as always! Thanks!

  21. This Precautionary Principle is a European invention and you are absolutely correct Doug that is exactly what it is. The only difficulty with the thing is the criteria is not well articulated or defined.

  22. I really hope this thing cools off before next Friday as my sister is due to fly out of the UK then. Come on Icelanders, do your ’70’s trick.

    OT, but with the number of eruptions and earthquakes sticking around the world recently, today, Adelaide, South Australia, experienced a magnitude 3.8 quake today. Strangely enough, Australia is one of the most geologically stable land masses on earth.

  23. I knew what they were saying was theorhetically correct but not realistic. Thanks for the analysis Steven, and for providing the facts to confirm my suspicions.

  24. Well done Steven. I think that settles the melting-point question.

    I admit I only skimmed the SA piece, but the general idea that melting ice sheets might lead to increased volcanism struck me as credible not because of this factor but because of isostatic rebound and its effect on already-volatile regions such as seams between tectonic plates. Melting ice sheets would be like removing compression bandages from unhealed wounds (a naive metaphor, but you get the idea).

    I realise that isostatic rebound is a very slow process, taking place over 100’s of years. Do you have a take on the types and magnitudes of the forces involved at how they compare to the orders required to trigger volcanism in such regions?

  25. Responding to Wren: “Maybe, unless the MWP wasn’t very W.”

    Even the AGW alarmists concede a regional MWP that affected Europe and Greenland. Maybe it skipped over Iceland.

  26. Here’s the original paper from GRL on glacier retreat and volcanic activity in Iceland:

    http://homepages.see.leeds.ac.uk/~earcpa/2008GL033510.pdf

    It’s always better to critique the paper itself, rather than a press release.

    In essence, the subsurface pressure changes caused by ice melt (equivalent to the loss of 5 cm of rock per year) are the same order of magnitude as the normal mantle upwelling rate beneath Iceland (1-10cm/yr).

    Magma production increases with the upwelling rate. So the current rates of ice loss would be expected to increase the rate of magma production (in the area under the ice) anywhere from 500% to 50%- a pretty significant increase, IMO.

  27. Actually this is too silly to reply to. It is Voodoo science in the extreme. If one thinks that glaciers have any impact on tectonic vulcanism at all, then they need to check themselves in at the home. And Iceland is ‘blessed’ with not only a very active moving plate or ridge, but a continuing shallow hot spot allowing for the more familiar conic activity.

  28. Steve: Correction needed!

    “…one basaltic mineral – diposide….” I think you mean: diopside.

    Otherwise, good article. Where are these “geologists” making these ridiculous claims coming from? They are as pathetic as Eric what’s-his-name from U. Washington.

  29. Put this another way and one could say that, according to the S. A. article, if/when the earth goes through another ice age, will much of the world volcanism cease? Are volcanoes an interglacial phenomena. I used to love Scientific American, now I have a hard time trusting any of it because of the high B.S. factor. Anybody know another good science magazine that has a little integrity left?

  30. Once the ice, which yields water which yields steam which imparts an explosive dimension to these eruptions, is gone, these volcanoes should revert to something like Kilauea – very little ash production.

    Another place where ice could pose a problem in relation to volcanism is Mt. Rainier. If that volcano resumes activity (it’s only dormant) the glacier covering the upper portion of the mountain could rapidly melt, posing a threat of catastrophic flooding and mud flows in a heavily populated area. The potential for destruction of property and life is high.

  31. When I read this article earlier this week (linked elsewhere) my jaw dropped. Scientific American lost their patina of respectability as a scientific publication decades ago. Now they are trying to compete with Art Bell’s “Coast To Coast” with George Noory?

    When will Richard C. Hoagland appear on the cover?

  32. “The economic damage now being inflicted by the
    volcano ash upon the British and European economies
    appears to be on a scale equivalent to the
    economic damage recently inflicted upon Iceland
    by the activities of UK and Europe.”

    …The financial crisis in Iceland was brought upon itself mainly by three Icelandic billionaires who all face criminal prosecutions. They colluded with Icelandic banks which had access to cheap international money markets mainly based in London and Europe. When international interest rates went up due to the massive mortgage scam in the U.S., the Icelandic banks could not cover their loan repayments, so they attempted to recover their losses by calling in the loans made to these billionaires, amongst others. The billionaires and some other big borrowers defaulted on their loans because they had gone on a gigantic spending spree, creating their empires of various companies bought with all this hot money and they didn’t have the cash, which in turn triggered the banks themselves to default on their loans to British and European banks. If that is what you call “inflicting damage on Iceland” then that is your interpretation. The damage inflicted by Iceland on the British banks which lent them the money in the first place, and through them the British economy has yet to be calculated. In the meantime, we would like our money back.

  33. Pearland Aggie (20:51:23) :

    Here is a good explanation and experiment from Argonne National Lab which demonstrates the melting of ice under pressure.

    http://www.newton.dep.anl.gov/askasci/gen99/gen99523.htm

    The link you provided assumes that pressure is equally applied under the skate, which is incorrect. The ice surface is rough, so the pressure on individual ice crystals is much higher.

    Ice gets much less slippery at lower temperatures.

  34. Steve Goddard, you may want to include the following paper in your post:

    http://www.evropusamvinna.is/Apps/WebObjects/HI.woa/swdocument/1015721/Sturkell_etal_2009b.pdf

    In it the seasonal seismicity and its potential relation to water pore pressure above a magmatic chamber is described. Clearly the “alarmist” stuff might be an extension of a local observed phenomenon in order to conveniently link an icelandic eruption to global warming and milk it.

  35. Re closures of commercial (and military) flights:

    http://www.metoffice.gov.uk/aviation/vaac/vaacuk_vag.html

    Graphics update every 6 hours or so.

    German combat troops in Afghanistan have been told not to get shot because (at least for now), they can only be casevac’ed to Istambul. So (according to Deutsche Welle) they’ve retreated to barracks, along with others. Instead of making arrangements to casevac to/via alternates like Perth (Western Australia) via DXB. I know that it’s more than twice as far but you can make the distance.

  36. No no no no no.

    This is a variation on the “Katrina was a devastating hurricane, therefore global warming causes more hurricanes” meme.

    It is also the meme that everything that can possibly be even remotely associated with global warming is fair game to be tagged “due to global warming.” The scientists all have seen a lot of money flowing to people who can tie their work to AGW well enough, so hell, why shouldn’t they try? Funding is funding, right?

    Anthony, you referred to it as a “theory.” If I might say, this is just a speculation, not a “theory.” Just because a “scientist” throws an idea out there doesn’t give it status as a theory. The entire golobal warming theory has quite a bit of evidence behind it even while it also has a lot of evidence against it. This thing just popped up, so it has a long way to go before it can be called a theory.

    The last I heard, Scientific American is news media, not a scientific peer-reviewed journal. Scientists have NO business throwing even well-thought-out ideas out to the news media before they’ve put the idea through several of the rigors of scientific inquiry. That is what got Pons and Fleischman in so much trouble in 1989. The speculation of the moment does not make a theory. At best, it is a hypothesis.

  37. If the water were gone, it is true the volcano would have far less ash propulsion. But i do not believe it will be anything like Kilauea. It has a far higher silica content because that is the nature of tectonic plates. Kilauea does not have such. Then this is a rift eruption, which mean it is not generally conic but lateral. This causes additional problems. Bad ones. Let me cite an example. Loihi is under a great deal of water. 9000 feet off of Hawaii. While water inundates it, that water has virtually no effect on the vulcanism or the make up of ash. The pressure of the water is likely heavier than this glacier. The depth of the magma source for Hawaii volcanoes makes Hawaii a relatively benign volcanic erupter, although the water and silica of sufficient concentration (under other circumstances are explosive. In the Hawaii instance, as I understand it, water only serves to encourage solidification and channelization. Iceland has rift eruptions with silica and water. In many respects this is far more dangerous.

  38. Waking up this morning in southern England, I can see and taste the dust from the unpronounceable Icelandic volcano. We also had some global cooling overnight, 1decC this morning. Everyone is coughing too.

  39. >>hmmmm….my next book will be a romantic novel about a
    >>traveling volcanologist named Steve who is called in to calm
    >>the nerves of jittery EU air travelers….I’m thinking of calling it
    >>“Return to Reykjavík”.

    Will he carry a red hanky?? ;-)

    On a more serious note, does the pressure of the ice on the surface seal up more potential vents? – so will the melting ice weaken the surface and open up the area to much more vucanism??

    .

  40. >>I’m not sure melting point has a lot to do with it.

    Surely it is the outgassing pressure in the magma that is critical here (whatever name this critical pressure has).

    The magma behaves like a soda bottle, and with sufficient pressure on the soda it is stable. Release that pressure, and suddenly it effervesces and “boils” up all over the place.

    .

  41. Ah, so that’s why the nearby Katla erupted in 1580, 1612, 1625, 1660, 1721, 1755, 1823, 1860 and 1918.

  42. Step 1: Invent Global Warming
    Step2: Blame anything “current” on Global Warming
    Step3: Tax, Tax, TAX!!!!

  43. Mike Odin (20:17:45) :

    The economic damage now being inflicted by the volcano ash upon the British and European economies appears to be on a scale equivalent to the economic damage recently inflicted upon Iceland by the activities of UK and Europe. This is simply a non-judgmental observation unrelated to any karma or other introspection.

    An interesting observation Mike. Was karma also responsible for the attempt by some mad Icelandic bankers to destroy West Ham United Football Club?

  44. The Norwegian Prime Minister was stuck in New York because of “The Cloud”. Then he managed to get to Switzerland, and is now in a car on his way to Norway.

    They talk a lot, but dont act as if they believe in their own saying.

    Why dont they use Video Conference’s. Why all this travelling? The only outcome is [snip], anyway.

  45. Kate: “…The financial crisis in Iceland was brought upon itself mainly by three Icelandic billionaires who all face criminal prosecutions.”

    The financial crisis was created using the old “socialist” scam of borrow-to-boom-to-bust except with a new twist: this time the government didn’t do the borrowing themselves.

    In the old version, the governments would borrow from international money markets and then spend the money on job creating schemes which would in turn create money in the pockets of those being employed who would spend the money creating more jobs. The big problem being that the wage-inflation caused by this spending made (e.g.) UK goods uncompetitive meaning much a lot of this money went to companies outside of the UK.

    And as everyone knows, sooner or later the money has to be repaid, at which point the government must cut back spending, reducing money going into the economy, cutting secondary jobs from those employed on government contracts resulting in a massive and nearly always greater (capital repaid+interest) hit to the economy.

    This time, this borrow-to-boom-to-bust “debtoconomic miracle” was accomplished by freeing up personal and business borrowing and instead of government going on a spending spree, the government “covertly” encouraged (i.e. actively stood back and applauded) the massive rise in personal and business borrowing which I think boosted the UK economy by a massive 10% year in year out throughout Labour’s reign of debt.

    And what really scares me is the way our political classes debt-addiction means they keep telling us like some sick junkie that all that is needed is “just one more fix” of debt “got to have it to enable them to pull themselves together so that they can sort out their lives/economy”

  46. Doug in Seattle (21:36:41) : shutting down all air traffic over northern Europe seems an over reaction.

    The density of the dust cloud is very thin, but jet engines ingest a huge volume of air, and there would be a significant flow of foreign material through the engine.

    For the engine compressor, it would be like being sand blasted. Clean, shiny smooth blades are best for efficient compression.

    The dust melts at the high temperatures of combustion, and it sticks onto downstream surfaces. This distorts the aerodynamic profiles in the turbine, resulting in further power reduction. The additional mass on the blades would cause vibration.

    The engine control systems would shut the engine down as the departure from the normal operating range would be diagnosed as a fault.

    If the engine could be forced to keep running, the turbine clearances would eventually be bridged, causing rubbing and lumps to break off, and a cascade of damage flowing down through the turbine. There wouldn’t be much left after that.

    Not a good idea to fly with any of the above going on. Better late than dead on time – the authorities did the right thing.

  47. @ Kate (23:24:52) :

    That’s what happens when the Progressive’s tie the worlds economies together. The idea was to create M.A.D. (Mutually Assured Destruction) through economies instead of weapons. However, someone didn’t really think it through real well (typical for Progressive’s and Greenie’s), as is becoming increasingly apparent.

  48. Al Gored (21:20:21) :

    The ash will block out the sunlight if it keeps it up. No summer. Then fresh snow can fall on the ash and effectively bury it. I watched a special where ancient supermassive volcano hunters found what they were looking for in Greenland. Didn’t stop the Ice Cap there.
    I’m not going to get worried about the warmists who will grasp at every hypothetical straw, no matter who says what.
    We both know that whatever they come up with, they’ll sure as shouting make a total mess of it. People who are prone to panic don’t have a habit of thinking things through prior to jumping on the PA system.

  49. A long time ago on WUWT where I think the subject involved Geo-engineering and the various “climate scientists” who were advocating all sorts of totally hare brained and potentially catastrophic global climate geo-engineering projects to “stop global warming”, a poster made the comment to the effect that a scientist of his acquaintance had told him, “when you can show me that you can control a volcano then we will sit down and discuss controlling the Earth’s climate!”

    I have never forgotten that comment and every time I hear of another significant volcanic eruption I think of that comment and just smile at the hubris and stupidity of those who believe that they have the power to change the global climate and can and will change it to their requirements IF, of course, you give them enough money!
    Of course if you ever suggested to these same global climate geo-engineering advocate “scientists” that they first try to exercise control over a small but significant and natural global phenomena such as the current volcanic activity in Iceland which is a quite small item compared to other historic examples of volcanic activity and is a particularly small item when compared to the global climate, they would consider you to be quite mad!

    The deficiency in mental capabilities actually resides with the global climate geo-engineering advocates when they can’t even demonstrate ANY ability to modify volcanic activity of any sort and yet claim to be able to geo-engineer the global climate to a set of specifications that they have, in their hubris, judged to be of an absolute necessity for the continuation of human life on this planet.

  50. One cannot write a valid article with these deductions without knowing the properties of the rock between the base of the ice and the top of the magma.

    There is no certainty that this mass of rock has any capability to transmit the changes in pressure/thickness from the ice above it to the magama below it.
    This rock can be considered as an incompressible load-bearing arch, at one end of a spectum of possibilities, and a spongy material like the matress on a bed that can transmit pressure through its thickness to its base at the other end of possibilities. The authors of the original article are aware of this.

    For example, you can remove a brick near the base of a high brick wall without causing significant change. The surrounding bricks do not usually collapse under pressure to fill the void.

    There is widespread misunderstanding of the meanings of pressure changes with depth in rock layers. It is not the same as hydrostatic pressure, like water in a well.

    The properties of this mass of rock, such as faulting and fracturing, the amount of such, the directions of such, the intrinsic rock hardness, elasticity, amenability to isostasy and other factors determine its behavior. Often these are not known well, because the world’s deepest drill holes seldom go more than 10 km deep. The magma here is modelled at 25 km depth. It is not possible to drill from surface to magma using any known technology, so models have to contain assumptions.

  51. The amount of pseudo scientific [snip] to which we are subjected on an hourly basis makes you very cynical.

    No doubt the EU aviatio agency that seems to have been most active in grounding everything has the safety interests of the travelling public most at heart. But I have yet seen a sensible explanation why jetliners can’t fly under the ash cloud. No one expects them to hedge hop. But, despite what is being put about in the media, planes can fly at 5 or 10 thousand feet. OK, they are designed for 30,000 ft and they do use more fuel. But unless I’ve missed something, it would surely be better to have some planes flying lower than just grounding everything?

    Couldn’t be anything to do with another EU “beneficial crisis” with a grab for control of aviation in the pipeline, or could it?

    And taking the focus off what’s happening in Greece?

    Surely not?

  52. Great article, Steven!

    To “Just The Facts”: Yes, it’s very disturbing that political leaders seem all to be planning for unverified negative consequences of a possible hotter future, while they appear to ignore the possibility of a sudden planet-wide cold spell. The most important measure would be to stock more cereals again. Currently, there’s quite a surplus of wheat grain (after two good seasons since the food crisis of 2008), so this may be a good time to start.

  53. Scientific American knows tabloid science sells well.

    How long before Paris Hilton is linke to Global Warming in Scientific American ?

  54. The pressure of Ice has nothing to do with a volcano surpressing an eruption.
    Unlike water pressure. Water pressure is designed to collapse on itself and cover a huge area depending on depth if you desplace water.

    Since the boughten theory is that our core is made of nickel, then the mass of nickel must be fire proof from burning and turning to ash with the incredible pressures and heat.
    This theory does not stand up.

    After 4 billion plus years and we still have pressure build-up which causes earthquakes and volcanoes.

  55. So we wander off into ice-skating …. I think you will find the pressure theory is wrong, and Pearland Aggie post is right. Ice near melting point is just very, very slippery. It’s a surface effect. If you ever tried to pick up a peice of ice that dropped out of your glass onto a hard surface, you would just ….. know that.

  56. >>Not a good idea to fly with any of the above going on.
    >>Better late than dead on time – the authorities did the right thing.

    It is a matter of density, surely.

    In OZ jet aircraft flew through many a dust storm (silicates) without too much problem. That is because they avoided the worst of the dust, but it still abraided the leading edges of the wings.

  57. @Pearland Aggie (20:51:23) :
    Be fair, Steven’s account was the Settled Science for many decades, a universal consensus.

  58. Geoff Sherrington (03:00:43) :
    A+ Science!

    Espen (03:21:24)
    All it takes is a few cool summers to suppress plant growth and we are in deep trouble. Food prices would soar astronomically and collapse the free market system and make currency worthless.

    Since scientists are falling from the high positions society has put them in of “All Knowing”. Science itself has made many an error by no one questioning the validity of theories and are they correct.

    If I generate a theory, I rip it apart and turn it any way possible to see if it will stand up to the best questioning. I must be doing a hell of a good job as no questions or replies means I must be doing something correctly. On the rare occassion I get a “Very Interesting”.

  59. Jordan (02:05:09) :
    That only happens if you are stupid enough to fly through the Cloud itself, which can be easily seen, plus they can fly under or over it.
    As Ralph (03:46:41) : surely it is the density that they fly through is the main problem.

  60. “lgl (01:13:44) :

    Ah, so that’s why the nearby Katla erupted in 1580, 1612, 1625, 1660, 1721, 1755, 1823, 1860 and 1918.”

    The eruptions are primarily due to temerature differentials, as with all eruptions.
    A very cool month or so followed by a strong uplift in temperature is what triggers
    volcanic activity. Katla eruptions:

    http://www.volcano.si.edu/world/volcano.cfm?vnum=1702-03=&volpage=erupt

    July 1999, cold June followed by hot July.
    Late June 1955, very cool start to June, warms up at and of month.
    Oct. 1918, Cool September, turns warmer in October.
    May 1860, very cool Feb to April, then very warm May.
    Late June 1823, same pattern as 1955.

    It is hard to find many exceptions to this pattern of volacano eruptions occurring at a strong temperature uplift after a cold period, in the complete list of VEI 4+
    events globally; http://www.volcano.si.edu/world/largeeruptions.cfm

    Fears of Katla erupting this June; http://www.newscientist.com/article/dn18690-iceland-waits-for-volcanic-shoe-to-drop.html
    are most likely misplaced. My solar based temperature forecast for this May and June is generally above above average, so I do not see any strong temperature differentials occurring through these months.

  61. Fitzy @21:03:09

    Latest edition of NGM carries an article on melting Himalayan glaciers. Not referenced so can’t check the source. The description of a “glacier” being ” a deathly shade of black” and “losing mass from the surface down” would indicate soot causing melting rather than increased temperatures. There is a statement that 40% of the glaciers could be gone by 2050. Sounds familiar.

    The NGM used to be a great source of information but it has become a mouthpiece for the AGW brigade. Pity.

  62. “The reason that people can ice skate is because the pressure under the blade creates a thin later of melted ice which lubricates the surface.”
    Balderdash. The pressure is nowhere near enough to melt the ice. The pressure from an ice skate would change the melting point by a few tenths of a degree at most. Ironically, this is the whole point, albeit with a different sign, that Goddard’s article is trying to make.

    http://www.faculty.virginia.edu/lehmannlab/badchemistry.html#ice

    Furthermore, why do hockey pucks slide so well on ice? Or curling stones? Why do folks slip over wearing ordinary shoes on an icy sidewalk? The pressure? Give me a break.

  63. Uh oh Main Stream Media just made a big boo boo. A few minutes ago a very animated and seemingly brilliant physics professor (an Asian male – I missed his name) gave a stirring description of how glaciers/ice are making this eruption far more damaging – as in the conclusion above state.

    Some ABC Good Morning producer is being called on the carpet right now for screwing up the narrative.

    Priceless!

  64. I believe that volcanic eruptions must be due to local accumulations of relatively low density magma that progressively become more buoyant, perhaps from gradual infusion of dissolved subterranean gases, until a point is reached that a surface failure occurs and the dissolved gases leak explosively into the atmosphere.

    I suspect that this Icelandic volcanic event has been ‘a long time coming’ and would have occurred sooner or later no matter what had happened to the arctic ice-pack above.

  65. ROM (02:49:44) [various “climate scientists” who were advocating all sorts of totally hare brained and potentially catastrophic global climate geo-engineering projects to “stop global warming”]

    National Geographic keep broadcasting documentaries for kids about these hare brained schemes. I think we should make a list of those “scientists” and who pays them.

  66. David Hall (03:31:27) :” If you ever tried to pick up a peice of ice that dropped out of your glass onto a hard surface, you would just ….. know that.”

    Hate to wander again but ice skates blades are not flat on the bottom. They are ground into a concave surface so that the edges cut into the ice and the water from the melted ice caused by the overall pressure fills the concave area thus allowing you to move. If there were no edges it would be difficult to turn sharply or start and stop quickly. Hockey skates have a deeper concave grind and figure skates less because the requirements of what the blades need to do are different. Picking up a piece of ice with your hand that dropped out of a glass is totally different than what skates do.

  67. Well I’m anything but surprised to see these politically ‘useful idiots’ trying to scare people with a .0005 change in the melting point of magma after they successfully managed to convince so many people that global warming itself was because of a .00002 human addition to the atmosphere.

  68. Anthony: If anyone is in the first group to be shot under new ECO-CIDE thinking it’s you! We’re going to miss you! It’s been great fun but it was a bit silly of us to chaff at a concensus of so many…..um….so many…..I don’t know who they are.
    ————————————————————

    Club Of Rome Behind Eco-Fascist Purge To Criminalize Climate Skepticism

    Ultra elitist organization that openly bragged of inventing global warming scare to manipulate population behind new onslaught of green fascism which would criminalize questioning man-made climate change

    Paul Joseph Watson
    Prison Planet.com
    Tuesday, April 13, 2010

    The British lawyer who last week called for introducing international laws through the United Nations which would make it a crime against humanity to question the reality of man-made global warming has close ties with the Club of Rome – the ultra elitist organization which openly bragged of how it invented the climate change scare as a means of manipulating the global population to accept world government.

    British lawyer-turned-campaigner Polly Higgins (pictured top) recently launched an initiative to have the UN put pressure on national governments to pass laws that would declare the mass destruction of ecosystems a crime against peace, punishable by the International Criminal Court.

    Under the guise of going after big corporations and polluters for the war crime of emitting the gas that humans exhale and plants breathe, the proposal would actually target individuals and people who merely express skepticism towards man-made global warming.

    “Supporters of a new ecocide law also believe it could be used to prosecute “climate deniers” who distort science and facts to discourage voters and politicians from taking action to tackle global warming and climate change,” reported the London Guardian.

    Some respondents to the Guardian article agreed that merely questioning whether man-made climate change was real should be criminalized – literally calling for the establishment of a UN-run thought police that would prosecute anyone who expressed dissent against the AGW belief system.

    “Would be nice if corporate-sponsored climate change denial was made an offence,” wrote one.

    “Think about that lineage and possible development of a war-crimes-style trial: Come up with an issue that will fit the bill to terrify the public into accepting the strictures and governance that you demand out of fear of overpopulation (and a general control fetish), then follow that up with putting those who challenged you in the dock,” writes Planet Gore.

    “I’m thinking hard, and have catalogued quite an inventory already, but must admit that this might be the best manifestation of the greens’ fascistic tendencies and totalitarian bent.”
    ————————————————————-

  69. The grounding is a procedure invoked when a BA ‘four engined’ plane had a four engine simulateous flame out. They were able to descend and relight. They say By the time the pilot notices the presence of ash, it’s probably too late and so the safest thing to do is ground every thing down wind.

  70. It may have been the Discovery Channel showing hare brained geo-engineering schemes rather than National Geographic.

  71. Eyjafjallajokull aka Island-Mountains Glacier web cam LIVE!

    http://eldgos.mila.is/eyjafjallajokull-fra-thorolfsfelli/

    This is how you say “Eyjafjallajokull ”

    [audio src="http://upload.wikimedia.org/wikipedia/commons/1/10/Eyjafjallaj%C3%B6kull.ogg" /]

    Listen to it 100 (or maybe 1000) times and you’ll be able to say your first word in Icelandic!

    http://en.wikipedia.org/wiki/Eyjafjallaj%C3%B6kull

    “Eyjafjallajökull (pronounced [ˈɛɪjaˌfjatlaˌjœːkʏtl̥], translated as “island-mountains glacier”) is one of the smaller glaciers of Iceland. It is situated to the north of Skógar and to the west of the larger glacier Mýrdalsjökull.

    The icecap of the glacier covers a volcano (1,666 metres or 5,466 ft in height) which has erupted relatively frequently since the Ice Age, at times bringing rhyolite to the surface.[1] The volcano erupted twice in 2010, on 20 March and 14 April. The April eruption caused massive disruption to air traffic across Northern Europe, with scientists claiming it was ten to twenty times more powerful than the March event. The most recent previous eruption was from 1821 to 1823, causing a fatal glacial lake outburst flood.[citation needed] A previous eruption was in 1612. The crater of the volcano has a diameter of 3–4 kilometres (1.9–2.5 mi) and the glacier covers an area of about 100 square kilometres (39 sq mi).

    The south end of the mountain was once part of the island’s Atlantic coastline. As the sea has since retreated some 5 kilometres (3.1 mi), the former coastline has left behind sheer cliffs with a multitude of beautiful waterfalls, of which the best known is Skógafoss. In strong winds, the water of the smaller falls can even be blown up the mountain.”

  72. This eruption might, like the last one, last for two years. Thus some worst case planning by the airline industry is in order, including design changes.
    A couple that come to mind:
    Filter systems for the engines. Don’t military helicopters already do this?
    Abradable coatings for the windscreens and leading edges, which would need to be easily replaceable.
    As an alternative, invest in cruise lines!

  73. I recall saying a little while ago that the solution to AGW was to blow up a volcano (I think I said ‘Nuc”) and cool off the Earth a little at a time. I think someone’s taken my Einsteinian Solution and used it before I could get a good patent attorney to file my invention. I also think someone at this website is responsible for this theft and the current situation in Europe. On last count there were 42,002,317 of you who are possible suspects (minus 1 – myself of course). Each of you can expect to hear from my attorney in the near future. I fully intend to get my due.

    PS: There’s a thief in our midst. Beware!
    boo hoo boooo hooooo

  74. More proof of AGW, we now have competing theories, so if volcanoes in Iceland become stronger or more frequent or less dangerous, then we can use that as proof of AGW.

  75. Perhaps Freysteinn Sigmundsson has cause and effect the wrong way round?

    It is possible that it can take many years for the magma to build up in the chamber beneath a volcano enough to trigger an eruption. During this period the bottom of the covering glacier will be heated by conduction and the ice will slowly melt.

    Thanks to Steven Goddard, whom I think is right on the money.

  76. See http://en.wikipedia.org/wiki/British_Airways_Flight_9

    From this article a plane flying through a volcanic ash cloud that could not be detected by onboard instruments had the following problems:

    1. The windscreen was sandblasted and the crew could not see through it.
    2. Landing lights were damaged.
    3. Fuel was contaminated.
    4. All four engines were damaged.

    The decision to ground aircraft in the UK and Europe is the sensible one.

  77. I would have thought that the Earths tectonic plates are going to keep moving about with or without any surface heating or cooling, or changes in downward pressure from the surface, because all the movement is driven by the underlying currents below the earths crust. If there is an effect from a lessening downward surface pressure then I would have thought that there would be an increase in tectonic activity with a lessening of intensity.
    The logic of this heavy ice argument should mean that when a volcano grows and gains mass it should switch itself off as it’s growing downward pressure increases the melting point of the underlying magma. A kind of feedback mechanism.
    Anyway there’s a joke in here somewhere to do with hell freezing over.

  78. “So the loss of the glaciers would reduce the size of the steam/ash cloud and make the Iceland volcanoes behave more like Hawaii volcanoes.”

    I learned from two vulcanologists back in 1970 that there are two main types of magma, and thus volcano behavior. They have been given Hawaiian names, “a-a”, and “pa-hoi-hoi”. The former, IIRC, is placid and just runs quietly out of the volcano, forming streams of lava. The second type is the explosive one that throws ash high into the air.

  79. Geologists to the rescue again!
    A nice concise post.

    This addresses the pressure-magma chamber theory, but it doesn’t address the change in the stress field, which in theory could change the ability for existing magma chambers to erupt. Not saying that it will, just that it hasn’t been quantified. It is interesting that they assume that the land rising is due to current ice loss and dismiss or never consider the possibility that it is from a) paleo-ice loss or b) inflation of a magma chaamber

  80. “So the loss of the glaciers would reduce the size of the steam/ash cloud and make the Iceland volcanoes behave more like Hawaii volcanoes.”

    I learned from two vulcanologists back in 1970 that there are two main types of magma, and thus volcano behavior. They have been given Hawaiian names, “a-a”, and “pa-hoi-hoi”. The former, IIRC, is placid and just runs quietly out of the volcano, forming streams of lava. This is the type seen in Hawaii. The second type is the explosive one that throws ash high into the air.
    The only volcanos that I have seen were in Japan, and they were only the explosive type, throwing ash high into the air. Sakurajima, near Kagoshima, regularly dusted the city with ash when I was there, and sweeping up a thin layer of black dust was a morning ritual.

    IanM

  81. I’ve subscribed to Scientific American for several decades and read every issue cover to cover. Overall it’s a great source for keeping up with a broad range of the sciences. The former editor, John Rennie, was a problem in that he is not at all objective on two subjects: global warming and evolution. In those areas he adheres to dogma rather than science and is fanatical about them. We’ll have to wait and see whether his temporary replacement, which will probably become permanent, is any different. I don’t expect a marked change as the clinging to climate and evolutionary dogma are systemic problems stemming from the political, religious, and social persuasions of a large majority of professors in academia. Our university faculties have become notoriously safe harbors for positive atheists and modern day liberals. Nowhere else in the world can one find such a concentration of people holding these beliefs.

    Disclaimer: I’m agnostic (weak atheist) when it comes to religion and lean libertarian when it comes to politics.

    As Sgt. Joe Friday of Dragnet fame often said to witnesses he was interviewing “Just the facts, ma’amm”. I’m only interested in the facts and the fact is that climate science has turned into climate dogma where science, like Elvis, has left the building.

  82. Symon (04:57:32) :

    I often ride my bike on ice and packed snow at -20F, as it is not very slippery. But at +20F, it is extremely slippery. Ice at +20F is slippery because there is always a thin layer of liquid water on the surface.

    A wide surface area hockey puck or bottom of a shoe, slide for different reasons than an ice skate – which digs into the ice. Tire chains and studs also dig into the ice and greatly increase friction, whereas a skate greatly decreases friction. Why is that?

  83. Could it be that the missing energy could be found in the graves of Galileo, Newton, Maxwell, Bohr Einstein etc where incoming solar energy has somhow induced the remains of these scientific giants to spin rapidly around the (formerly) vertical axis?

  84. Steve,

    Your analysis of teh pressure effect on magma is complete and convincing.

    However, you’re off-base on the physics of ice skating. The link you cite involving the piano wire and ice cube classic experiment (1) doesn’t really apply to ice skating directly since the pressure effects are larger due to the wire’s very tiny diameter and (2) involves other effects, primarily the rapid conduction of ambient heat to the ice cube from the warm room. When this experiment is done in a freezer, it ceases to work.

    Here’s Cliff Swartz, well-known physics textbook autor on the myth:

    “Ice skates experience low friction because a thin water film is
    produced between blade and ice. A popular legend has it that this
    effect is caused by the lowering of the melting point due to the pressure exerted by the blade. It is true that one of the unusual features of water is that it expands during freezing. Consequently, if we prevent the expansion by increasing the pressure, we prevent the freezing and
    thus lowwer the melting point. The usual pressure-temperature diagram
    for water shows the boundary line between solid and liquid arching back to the left from the triple point. However, the actual effect is very small.

    The slope of the boundary line is -(1.2×10^7 N/m^2/C) It would take an
    increase of 120 atmospheres to lower the melting temperature 1 Celsius
    degree. For the typical skate blade, the area is 27 cm x 4 mm = 11 cm
    If the full weight of a skater with mass 65 kg is exerted on one blade,
    the increased pressure would be about 6 atm. Sharpening the blades
    does not decrease the contact area appreciably, since the blade sinks
    down into the relatively soft ice.

    What does produce the water film between blade and ice? There are two
    plausible explanations. When the leading edge of a blade strikes the
    ice, the resulting friction energy can melt a trail for the rest of the
    blade. A more important effect stems from a phenomenon first noticed
    by Faraday and then largely ignored because it was not understood.

    We now know that at the interface between ice and air there is a thin
    film of water. The thickness increases from monomolecular to several hundred molecules as the temperature rises from -10 to 0 C. Since the
    reduction of friction depends on the the water film, you might conclude
    that the fastest skating could be done on ice close to the melting point.
    However, warm ice is soft ice, allowing the blades to sink in more. On
    the other hand, cold ice, which is hard, has only a thin film of surface
    water. These two competing effects yield a minimum of friction for
    speed skating at about -7 C. (For further details. see James White, The
    Physics Teacher, 30, 495 ((1992)).”

    Just FYI.

  85. It would appear that the some of the Icelandic eruptions have a pattern of extended and variable activity once activated. Previous Eyjafjallajokull volcano eruptions happened in 920, 1612 and 1821-1823. The last eruption lasted from December 1821 to spring 1823 and seemed to have several stages of eruption. An initial eruption, followed by some 6 months of more subdued activity, followed again by several months of very active eruption, and followed again by some 5-6 months of more subdued activity. Since both of the last two eruptions took place during already very cold global temperatures, namely the Dalton Minimum and the Little Ice Age, it is not clear how the ash may have affected the climate of that day.

    We know that the Pinatubo eruption of June 1991, affected global climate with cooler weather through 1993. [18 months?]

    Looks to me that the predicted record warm year for 2010 and a few years there after may again be at risk if this eruption turns out to be similar to the previous ones.

  86. @Steve Goddard (23:28:49)

    Have you ever tried walking on ice in rubber soled boots? I have. It’s still very slippery and you can’t claim that the sole of the boot has high pressure point contacts as you can with the skate blade because the rubber deforms easily. Yet on any other slippery-smooth surface the boot will grip like mad.

    A very thorough exposition and disposition of the pressure melting dogma through the good old fashioned experimental method can be found in a 2005 paper by Robert Rosenberg published in Physics Today.

  87. Espen (03:21:24) :

    “The most important measure would be to stock more cereals again.”

    We should also come up with a plan and resources to help our farming sector to rapidly adjust to a sudden change in climate. Most farms will need to change their planting & harvest schedule, many will have alter their crop and seed selections and a number may need to be moved to operate in more hospitable environments until temperatures recover.

  88. Jordan (02:05:09) :

    I understand all the potential problems. The question though is whether the actual conditions warrant the actions being taken.

  89. MrCPhysics (07:48:45) :

    Hockey skates are sharpened and concave, and the part contacting the surface of the ice is much thinner than piano wire. I’ve cut my fingers on ice skates many times.

    It is much easer to have an intelligent discussion when people avoid the use of the terms “myth” “consensus” or “established science.”

  90. A similar slant by a certain group was tried, with cyclones creating lower pressure and causing an increase in earthquakes

  91. re: Gerry (08:06:01) :

    Has anyone calculated yet how much global COOLING will be generated by the ash clouds????
    ————
    When Pinatubo erupted in 1991, almost everyone had been predicting a warm 1992. Only one or two took note. It took until June for the rest to figure out why there was cooling for a year or so (I do not have the figures handy)

  92. Well, i guess nobody noticed the link I posted earlier, so I’ll post it again:

    http://homepages.see.leeds.ac.uk/~earcpa/2008GL033510.pdf

    This is the original paper on the effect of ice loss on volcanic activity that is referenced in the Sci Am article.

    In short, hot rock melts when the pressure on it drops. The pressure drop can happen in two ways: 1) as the hot rock rises through the crust (the pressure decreases as depth decreases); or 2) by removing mass at the ground surface, which lowers the pressure at depth.

    In iceland, the hot rock is rising through the crust at roughly 5 cm/yr (plus or minus a few cm). The amount of mass loss from the glacier discussed in the paper is the equivalent of removing 5 cm of rock from the surface per year.

    So (in the area beneath the glacier) the amount of rock melting caused by the loss of the ice mass is approximately the same as the melt generated just by the hot rock rising through the crust.

    The net effect – the ice loss has (very) roughly doubled the rate of magma production in the area beneath the glacier.

    Although the calculations Steve G. has done are correct, his analysis and understanding is all wrong.

  93. When I first read the report on the link between melting glaciers and eruptions I was a bit skeptical. However isostatic rebound is known and measurable. I was a bit dismayed that everyone was so quick to dismiss it. Steve’s post and some of the articles dealing with the subject are models attempting to describe a complex situation. As such they are similar to climate models– the math and physics may be correct, but the underlying assumptions may or may not be correct.
    IMO the place to start is with the rock record. A paper by Slater and others in 1998 in Earth and Planetary Science Letters reports that Iceland eruption rates at the end of the Pleistocene (when deglaciation was much greater than today) were 20-30 times greater than today. I don’t have access to the full article so I can’t comment on the stregth of their data/methods. I believe that a look at eruption rates through time in places like Iceland, Alaska etc. would be a better way to go rather than relying on theoretical models.

  94. Doug in Seattle (08:47:55) : “I understand all the potential problems. The question though is whether the actual conditions warrant the actions being taken.”

    Its hard to guess other peoples’ background across the blog. Sorry about that.

    If it helps, the video in the following link confirms how measurements are being taken, so the decisions should be evidence based. That should help any concerns about over-cautious reaction.

    http://news.bbc.co.uk/1/hi/uk/8626625.stm

    People with expertise are offering views (like the guy in the video)m although I would expect the aitline operators will be consulting engine OEMs.

    I’m conscious that these points are OT for the thread.

  95. “Surely it is the outgassing pressure in the magma that is critical here (whatever name this critical pressure has).

    The magma behaves like a soda bottle, and with sufficient pressure on the soda it is stable. Release that pressure, and suddenly it effervesces and “boils” up all over the place.”

    Ah Ralph, but the soda boils up when shaken, gas pressure builds up and the cap is removed quicly. If the cap is removed slowly, like a slowly melting glacier, then nothing much happens because pressure is releasely gradually.

  96. stevengoddard (08:55:47) :

    Ian L. McQueen (07:40:18) :

    The explosivity of volcanoes is primarily determined by steam pressure in the magma chamber.

    Steven-

    Does this mean that magma is the same composition around the world?

    IanM

  97. Ulric Lyons (04:46:35) :

    The eruptions are primarily due to temerature differentials, as with all eruptions. A very cool month or so followed by a strong uplift in temperature is what triggers volcanic activity.

    I find it more likely that there is a common cause behind the two. Change of Earth’s rotation for instance.

  98. Far to many ’60s hippies spent far too much time staring at their lava lamps and drawing incorrrect, imbibed conclusions.

  99. Dave Springer (07:42:52) :

    “I’ve subscribed to Scientific American for several decades and read every issue cover to cover. Overall it’s a great source for keeping up with a broad range of the sciences. ”

    I’m a fellow SA fan – it’s a nicely done attractive magazine and generally fun and informative. I had no real awareness of AGW until Climategate and then I started paying attention and from what I have found AGW is a weak conjecture, physical measurements contradict it, historical climate records contradict it, there are no ill effects much less catastrophes anyone can point to as evidence for it that cannot be easily debunked by objective arguments and simple observation.

    Yet SA devotes almost the entire issue of a recent edition to what we have to do to save the planet from AGW and rounds it off with a paddy-cake, paddy-cake interview with Bill McKibben author or “Earth”. Preposterous.

    Thanks Steven for debunking the latest nonsense from SA; because even if it is a “nicely done attractive magazine and generally fun and informative” they occasionally print rubbish.

  100. The Katla volcano which is only about 25 km from the Eyjafjallajokull volcano has erupted just before the Eyjafjallajokull on three of the previous occasions. So there appears to be some correlation. The last eruption of Katla was in 1918, thus it has a current repose time of 92 years, the longest since about 1500 and Katla seems long over due since it typically erupts twice in a century. It has erupted in a major way about 9 times since 1580. Typical eruption periods were 13 days to about 120 days with last three being about 3-4 weeks.
    So it seems to me with all the world focus on manmade greenhouse gases and carbon dioxide only as piloted by IPCC , we have wrongly taken our eye off other natural planetary cycles and potential risks which are far more consequential and immediate. Lets hope that there will now be more sanity about this global warming issue and we start dealing with real world problems . Manmade greenhouse gases is the least of our worries at this time .

  101. Steven Goddard

    Good post: puts the “un-” to Scientific American

    Minor nit: did you mean diopside? “…relationship for one basaltic mineral – diposide.

  102. Thanks, Great Read

    [para 6, last line, the word later s/b layer]

    ========
    Melting ice caps may trigger more volcanic eruptions

    10:38 03 April 2008 by Catherine Brahic
source

    http://www.newscientist.com/article/dn13583-melting-ice-caps-may-trigger-more-volcanic-eruptions.html

    Vatnajökull is the largest ice cap in Iceland, and is disappearing at a rate of 5 cubic kilometres per year.

    Carolina Pagli of the University of Leeds, UK, and Freysteinn Sigmundsson of the University of Iceland have calculated the effects of the melting on the crust and magma underneath.

    They say that, as the ice disappears, it relieves the pressure exerted on the rocks deep under the ice sheet, increasing the rate at which it melts into magma. An average of 1.4 cubic kilometres has been produced every century since 1890, a 10% increase on the background rate.

    But the thinning ice has another effect on volcanoes which will be more widespread.

    As the amount of weight on the crust changes, geological stresses inside the crust will also change, increasing the likelihood of eruptions. “Under the ice’s weight, the crust bends and as you melt the ice the crust will bounce up again,” explains Bill McGuire of University College London in the UK, who was not involved in the study.

    =========

    “In short, the loss of all ice in Iceland would make the volcanoes less destructive.”

    Did you mean destructive or less active?

    Note: wouldn’t a gradual change in the ice cap introduce increased seismic reads if the weight is having a meaningful impact on geologic stress?

  103. So let me get this straight – are you suggesting the report was alarmist?

    All together now: WHODA THUNK IT!

  104. Ian L. McQueen (10:39:47) :

    There are several different types of magma, but Hawaiian and Icelandic volcanoes are both basalts. Hawaiian volcanoes do not normally generate a lot of ash.

    The most explosive volcanoes (like Mt. St. Helens) are andesite volcanoes with magma that is more viscous than basalt.

  105. Too much is being made of the decrease in lithostatic pressure that can occur due ti ice melting ant’s effect on temperature/pressure relationships of magma. I think Steven pretty well debunks this in his article.

    The coincidence of a series of eruptions with ice loss in Iceland in the early Holocene is just that in the absence of a coherent mechanism to tie the two together. This is so far lacking.

    Volcanism in Iceland is driven by oceanic plate spreading, not isostatic response to ice unloading (or fracturing in response to it). The magnitude of the extensional stresses associated with plate spreading, even on a local scale, such would be in pay in Iceland, simply dwarf those associated with the small amount of unloading that could be associated with ice loss in the past century.

    I can see the possibility of local structural effects modifying the direction of magma flow, or explosive reactions of magma to water/ice rich host material during an eruptive event, but beyond that ice accumulation or loss would not affect volcanism.

  106. Which is the source (and cause) of these hot spots?:

    http://weather.unisys.com/surface/sst_anom.html

    A US volcano with a clear “political spin”(clearly a subversive “tea bagger”) emitting tons of CO2 , a “civil desobedience” of EPA regulations?:

    http://volcanoes.usgs.gov/lvo/activity/monitoring/co2.php

    If you see the following images you´ll find them sinful:
    Plasma and volcanoes: http://geoplasma.spaces.live.com/blog/cns!C00F2616F39D0B2B!152.entry

  107. @Steve Goddard,

    The ice-skating question has been an interesting area of popular physics research over the last century or more. Michael Faraday, Lord Kelvin, and J. Willard Gibbs, three of the biggest names in the history of Physics, were actively involved with this question, and experimentally proved the “pressure-melt” hypothesis wrong. Modern research has confirmed Faraday’s hypothesis of a liquid “pre-melt” layer on top of the ice, which is what permits skating (and skiing, for that matter) down to about -30 C. There are MRI images, X-ray diffraction patterns, and AFM (Atomic Force Microscopy) images that absolutely confirm this hypothesis.

    Sorry about the use of the term myth, but what do you call something that’s taught in textbooks as truth, but is clearly either extremely oversimplified, or just outright wrong? There has been clear, compelling research (with actual data and methodology published, see above) showing that it’s NOT pressure melt that causes a water film to form under ice skates allowing ice skating to occur. Rosenberg’s article is the definitive summary on this, and the incontrovertible, factual evidence is that the maximum pressure generated by skates on ice is about 470 atm, enough to depress freezing point by ony about 3.5C, which would make skating impossible below that temperatures without the liquid “pre-melt” layer on top of the ice. The pre-melt layer is what makes it so slippery walking on ice with leather-soled dress shoes (check NHL coaches), too, and allows the puck to slide.

    I’m not trying to be obnoxious or belligerent here. You stumbled on a field I happen to know very well from my own research and teaching. I was just trying to set you straight. I’ve heard it said that no good deed goes unpunished and I may be experiencing just that…

    Your analogy has nothing really to do with your main point, which is excellent. Holding on to an analogy that is clearly false only hurts your credibility, something I would rather not see happen, since I agree with your position on the glaciers and volcanos.

    Please read the Rosenberg article and just change the analogy. I would have sent both replies by email had I known how. I hope the public exchange hasn’t hardened you into an unreasonable defense of your position.

    Sincerely and respectfully.

  108. Nice comment Mike Odin! I was thinking that too , the socialist banking “reforms” have really hurt a lot of people, I think it was the first leg of the plan that includes the AGW/ CO2 scam to reduce us all to serfdom (as my last name is Edwards I will not go back there)

  109. Its getting more ridiculous!

    Just caught a report on CTV (Canadian) in which the reporter explained that this volcano will keep erupting until the ice around it melts!!!

    Seems this intrepid reporter has discovered a previously unknown cause and effect relationship that is bound to have profound implications.

    By 2050 or 2030 or 2100 or whenever, when the world is 7 or 2 or 12 degrees warmer and all the ice is gone and Manhattan is a marine park, we won’t have to worry about volcanoes.

    LOL.

  110. Sorry for being redundant but Scientific American revealed itself as a purveyor of politicized junk science with their concerted and unprecedented attack on Bjorn Lomborg’s book The Skeptical Environmentalist a few years back.

    They are the kind of publication Mann and Jones approve of.

  111. Don’t know about the ice skate thing. I always had four pairs. two pairs of speed skates, (width about 1.5mm & flat ground with a whetstone), one pair hockey skates hand ground to be almost knife edged for extreme stuff, (Never slipped sideways unless I leant over so much the boot lifted the blade off the ice, groove almost half width of blade), & one pair hockey skates shallow ground for more general use.

    The deep ground blades were the slowest although that may in part be due to heavy ‘rocker’ grind where the lengthwise profile was like a rocking chair rocker.. I’m inclined to think the popular explanation is incorrect.

    DaveE.

  112. After reading all of the theories (er, hypotheses) expressed above about why ice skates work, I tried my own experiment using an ice cube taken from the tray under the ice-maker in my refrigerator. (They no longer look like cubes, but that’s immaterial — lets call it an ice polygon, or I-P for short.) So I laid my I-P on its side atop a multi-folded-up paper towel to insulate it from the Formica counter-top and applied the back side of a stainless-steel dinner knife pressing down as hard as I could.

    In less than a minute, the back of the blade had formed a deep groove in my I-P, and I thought maybe the ice-skaters had it right — all it took was some heavy pressure on a thin blade. But then I thought I should not have used a knife at room temperature and should repeat the experiment after cold-soaking my knife in the ice-maker tray.

    About an hour later, I retrieved the knife but it was too cold to hold and I had to wrap it in several layers of paper toweling before I could press the back of the blade once again on a new frigid piece of I-P. But this time, pressing as hard as I could, there was no groove formed under the back of the blade. So I turned the knife over and applied pressure using the sharp blade. Still hardly a groove could be formed!

    From results of this experiment I concluded that ice-skating works better if the blade is slightly warmer than the ice, and I presume it will be so as the skater’s blades travel through the ambient air following each stroke. It is also possible that AGW would benefit this process, but so would GW that is non-A.

  113. Just The Facts (08:46:28) :
    We should also come up with a plan and resources to help our farming sector to rapidly adjust to a sudden change in climate.

    Absolutely. And last, but not least, we should stop the crazy projects to turn food into fuel, especially US corn ethanol, which has a questionable net effect on climate gases anyway.

  114. Just The Facts (21:15:14) :

    “Looking at the picture of the venting volcano above it seems clear that volcanic activity is a driver of climate change that we must take very seriously. While we don’t know when, it is just a matter of time before a very large volcanic eruption, or possibly a cluster of big ones, causes an episode of rapid cooling like the year without summer:

    http://en.wikipedia.org/wiki/Year_Without_a_Summer

    We are very unprepared for this type scenario. Shouldn’t we be diverting some of our limited resources, including some of our good climate scientists, over to researching and preparing for an inevitable rapid catastrophic volcanic cooling episode? Solar panels aren’t going to be much help when millions of people are starving to death due to crop failures…

    REPLY
    “They” already have that covered. /Sarc

    Beginning in 1973, policy changes promoted by Nixon Secretary of Agriculture Earl Butz deregulated the corn market. He dismantled supply management policies, selling off government storage bins used as food security reserves…. Butz and agribusiness giant, Cargill, along with the Farm Bureau argued that farm prices crashing would be a positive because they would be remedied by more exports and new uses such as ethanol and corn sweeteners. The 1996 Freedom to Farm Act [written by Cargill VP Dan Amstutz] represented the culmination of this “free market” ideology by calling for the elimination, over 7 years, of all price floors and grain reserves.” http://www.nffc.net/Learn/Fact%20Sheets/King%20Corn%20Fact%20Sheet.pdf

    Here are the results
    “In summary, we have record low grain inventories globally as we move into a new crop year. We have demand growing strongly. Which means that going forward even small crop failures are going to drive grain prices to record levels. As an investor, we continue to find these long term trends..very attractive.” Food shortfalls predicted: 2008

    “Recently there have been increased calls for the development of a U.S. or international grain reserve to provide priority access to food supplies for Humanitarian needs. The National Grain and Feed Association (NGFA) and the North American Export Grain Association (NAEGA) strongly advise against this concept”
    July 22, 2008 letter to President Bush

    Riots from Haiti to Bangladesh to Egypt over the soaring costs of basic foods have brought the issue to a boiling point and catapulted it to the forefront of the world’s attention, …
    “The finance ministers were in shock, almost in panic this weekend,” he said on CNN’s “American Morning,” in a reference to top economic officials who gathered in Washington. “There are riots all over the world in the poor countries … ” April 14, 2008 – Riots, instability spread as food prices skyrocket

    “May 1, 2008 … Today, says USDA Undersecretary Mark Keenum, “Our cupboard is bare.” U.S. government food surpluses have evaporated….. “
    Surplus U.S. food supplies dry up – USA TODAY

    Ten corporations are busy consolidation a strangle hold on the world food supply. The bogus “Food Safety Bills” here in the USA were supposed to finish wiping out independent farming in the USA. One bill would even “regulate” home veggie gardens!

    If you want the real story behind the how the CED deliberately has been wiping out independent farmers in the USA and exporting the techniques to other countries check out
    History, HACCP and the Food Safety Con Job It is very well researched.

  115. RE: pwl (06:02:18) : [Eyjafjallajokull]

    For the Microsoft Voices Sam or Anna:
    a’ya vill lev vich’k
    seems to give results that approximate your audio file.

  116. RE: Espen (15:30:48) : “… we should stop the crazy projects to turn food into fuel,”

    If we ever have a major killing famine develop, such as might be caused by a major eruption of the Yellowstone Supervolcano, I think we could very well be forced into a desperate crash program to turn fuel [coal] into food.

  117. As of a couple of weeks, ago, we had over 7 Billion Bushels of Field Corn in Storage. Corn was selling for $3.50/bu, or just a touch over $0.06/lb.

    None of the food situations around the world in 2008 could, even remotely, be connected to Field Corn grown in the U.S.

    Shame on you, Gail.

  118. Hello…..?

    Doesn’t this ‘story’ then serve as yet another example of NEGATIVE FEEDBACK that the IPCC et al failed to account for in their models?

  119. Herewith more on our WeatherAction long range forecast of ongoing Volcano impacts on European airspace.
    FLIGHT PROBLEMS LIKELY TO CONTINUE TO 26th APRIL WARN LONG RANGE FORECASTERS
    Piers Corbyn of WeatherAction long range Weather, Climate & solar impact forecasters warns their long range European wind maps & predictions of likely solar effects on Iceland volcano spell ongoing trouble for airspace

    http://bit.ly/cPh4YT

  120. Kum Dollison (17:55:49) :

    As of a couple of weeks, ago, we had over 7 Billion Bushels of Field Corn in Storage. Corn was selling for $3.50/bu, or just a touch over $0.06/lb.

    None of the food situations around the world in 2008 could, even remotely, be connected to Field Corn grown in the U.S.

    Shame on you, Gail.

    REPLY:

    I did not want to get into the LONG explanation but here goes.

    These are the key points:
    July 26, 2002: Report Finds Fundamental Flaws in WTO’s Agreement on Agriculture: “Institute for Agriculture and Trade Policy report argues that the Agreement on Agriculture fails to account for agri-business’ monopoly over global agricultural trade.” http://www.socialfunds.com/news/article.cgi/891.html

    2002 Effect of policies on farmers in USA and Mexico: Between 1995 and 2000, the prices US farmers receive for corn declined 33 percent, 42 percent for wheat, and 34 percent for soybeans. No wonder that since NAFTA went into effect 33,000 small farmers in the US have gone out of business— more than six times the pre-NAFTA rate. In Mexico, the price farmers receive for corn has plummeted 45 percent At least 1.5 million farmers have left their land. 900,000 people leave Mexico’s land every year, a U.N. program says. According to a study by Jose Romero and Alicia Puyana carried out for the federal government of Mexico, between 1992 and 2002, the number of agricultural households fell an astounding 75% – from 2.3 million to 575, 000 http://www.globalexchange.org/campaigns/ftaa/topten.html

    INDIA:
    Farmer suicides in India: Now the full toll—surely among the largest sustained waves of suicides in human history—is becoming apparent. And as Sainath emphasizes, these numbers still underestimate the disaster, since women farmers are excluded from the official statistics… It is important that the figure of 150,000 farm suicides is a bottom line estimate…. “Overall,” says Professor Nagaraj, “there exists since the mid-90s, an acute agrarian crisis. That’s across the country. In the Big Four and some other states, specific factors compound the problem…. Cultivation costs have shot up in these high input zones, with some inputs seeing cost hikes of several hundred per cent… Meanwhile, prices have crashed, as in the case of cotton, due to massive U.S.-EU subsidies to their growers. All due to price rigging with the tightening grip of large corporations over the trade in agricultural commodities.” http://alternatives-international.net/article1394.html

    http://www.counterpunch.org/sainath02122009.html

    1986 Global commodity prices slumped in the mid eighties, triggering a five fold increase in farm subsidies in the USA and the EU subsidy to double. Pressure from commodity exporters inspired a decision to pursue Agricultural Policy reform at Uruguay round of GATT. It was lead by Under Secretary of Agriculture Dan Amstutz. http://books.google.com/books?id=0VyUe1kMc2wC&pg=PA68&lpg=PA68&dq=Daniel+Amstutz+Undersecretary+of+Agriculture,+1986&source=bl&ots=g_NvagIp9r&sig=iNU3jWVgC7LkAjkzuSQt6LyINfI&hl=en&ei=XF-gSavhGY-EtgeXjZz_DA&sa=X&oi=book_result&resnum=2&ct=result#PPA68,M1

    Launched in 1986, the General Agreement on Tariffs & Trade (GATT) Uruguay Round of international trade talks has been dominated by a confrontation between the US and the EC over farm policy reform. Both sides proclaim their commitment to devising a GATT regime which will bring an end to the anarchy in world agricultural markets, yet neither is willing to address the underlying cause of the present malaise: structural over-production in their own farm sectors and the resulting accumulation of surpluses. The use of export subsidies to put these surpluses on to world markets caused developing countries severe trade and food security problems in the 1980s; and a Uruguay Round deal is unlikely to bring any relief. What it will do, however, is introduce new regulations which, enshrined in international trade law, will restrict the right of developing countries to manage their own food systems. Most importantly, the use of trade measures to control food imports and price support measures to promote staple food production could be severely constrained, or banned, by a ‘farm superpower’ GATT agreement. http://www.informaworld.com/smpp/content~content=a769339885~db=all

    Trade Related Aspects of Intellectual Property Rights (TRIPS) introduction of intellectual property rules on plants, animals and seeds under WTO’s Agreement “could damage the livelihoods of these 1.4 billion farmers worldwide and undermine food sovereignty and food security ” Joint Communication from the African Group to the Council for Trade-Related Aspects of Intellectual Property Rights (2003) http://www.fao.org/docrep/007/y5714e/y5714e07.htm

    U.S. Corn Trade

    The United States is the world’s largest producer and exporter of corn. Corn grain exports represent a significant source of demand for U.S. producers and make the largest net contribution to the U.S. agricultural trade balance of all the agricultural commodities, indicating the importance of corn exports to the U.S. economy. On average, corn grain (excluding popcorn or sweet corn) accounted for approximately 11 percent of all U.S. agricultural exports by value during the 1990s. In 2008, due to record exports of corn and other feed grains, that share grew to over 12 percent of the U.S agricultural export value. http://www.ers.usda.gov/Briefing/corn/trade.htm

    The manipulation of corn and grain by the grain traders has forced independent farmers out of business here in the USA and in other countries.Thanks to tax payer dollars Cargill et al buy US corn at under the cost of production in the USA and Europe and sell at a lower price in other countries. This has forced farmers out of business. When there is a short fall like in 2008 their are no local independents to meet the demand. Both Cargill and Monsanto posted record high earning in 2008.

    If you can make the statement you made I strongly suggest you find out what is happening to your food supply. As I stated above Nicole Johnson wrote a very well researched article (referances are about 1/2 the article) at http://www.opednews.com/articles/History-HACCP-and-the-Foo-by-Nicole-Johnson-090906-229.html

    The food safety bills originated in the January 2005: Guide to good farming practices: This draft guide to good farming practices for animal production food safety was taken from the Report of the Meeting of the OIE Terrestrial Animal Health Standards Commission (Paris, 17-28 January 2005) http://www.oie.int/boutique/extrait/25berlingueri823836_0.pdf?PHPSESSID=64969a28688594daf57a7263f42fb1ce

    The first try to make it law in the USA was the 2005 Bill: Safe and Secure Food Act http://www.govtrack.us/congress/billtext.xpd?bill=s109-1534

    I have thirteen pages of similar references on the take over of the World Food supply if the above do not convince you.

    How about June 2006 – The Global Diversity Treaty: Standard Material Transfer Agreement (SMTA) a standardized contract that will enable much easier access to crop diversity. [ germplasm for patenting] royalty payment (1.1% of sales) is paid only if product is unavailable for further breeding and research. funds will be devoted to conservation efforts. Translation: Bio-techs Corporations steal seed from third world farmers, patents it and pay money to Bioversity International http://www.bioversityinternational.org/publications/pdf/1144.pdf

    Followed by April 2007 – Monsanto, Cargill and Maseca-ADM sign agreements to establish regional seed banks in the center and south of Mexico. http://www.counterpunch.org/ross11212007.html

  121. Surely you’re joking, Mr. Freysteinn!

    Iceland’s peachfuzz hoarfrost doesn’t weigh down the earth much. Some Icelandic egos seem to have reached the point of gravitational singularity, though. It might have something to do with all that press Jules Vernes gave them in Journey to the Center of the Earth. Things grow slowly on Iceland, including megalomania. They’ve got the elves, but the big fat man in the red suit is over in Greenland, where they have real ice, unlike Iceland’s semi-seasonal frost strata. Bah.

  122. Steve, how does the change in pressure from melting 500m of ice compare with moon tidal pull. Also,since the magma is already erupting below the ice, fracturing reaches the surface already. The ice would appear to be more vulnerable to the elevated geothermal temp below it than 1-2C air temp inc-

  123. If you have something that has been strained almost to its breaking point, it seems to make sense that any sudden small stress increase may cross the line and trigger a cascading fracture. I note that many earthquakes seem to occur when the sun and the moon are in-line — full moon or dark of the moon. That is when earth is seeing its highest tidal stresses for any given two-week period.

    When Mt. St. Helens was acting up I recall noticing that many of these eruptions seemed to occur just after an indicated high tide on the Puget Sound daily tide calendar.

  124. GaryPearse (07:08:53) :

    Tides are typically few feet, so I would imagine that the loss of 500 metres of ice would have a larger long term effect, though tides happen much more quickly.

  125. Doug in Seattle (12:28:39) :

    “Volcanism in Iceland is driven by oceanic plate spreading, not isostatic response to ice unloading (or fracturing in response to it). The magnitude of the extensional stresses associated with plate spreading, even on a local scale, such would be in pay in Iceland, simply dwarf those associated with the small amount of unloading that could be associated with ice loss in the past century”

    Yes the fractures are already there and they spread repeatedly giving access to low pressure at the surface. A common phenomenon is the eruption below an ice sheet that gives a flat-topped, steep sided volcano know as a “tuya”. I recall a smart wag many years ago exclaiming that this is the origin of the phrase “What’s a Tuya?” meaning “What do you care about it?”

  126. “lgl (10:39:55) :

    Ulric Lyons (04:46:35) :

    The eruptions are primarily due to temerature differentials, as with all eruptions. A very cool month or so followed by a strong uplift in temperature is what triggers volcanic activity.

    I find it more likely that there is a common cause behind the two. Change of Earth’s rotation for instance.”

    I don`t. LOD is also controlled by temperature change, not visa versa.

  127. I have a great deal of difficulty believing that the isostatic change or ice cap weight have anything to do volcanic events in a slip zone fault.

    Doesn’t the presence of the ice cap increase the ash production, if anything the current problems in Europe are exacerbated by the fact that the glaciers haven’t melted fast enough. If the AGW alarmists were right, thousands wouldn’t be stranded right now.

  128. “stevengoddard (06:56:42) :

    Piers Corbyn (20:22:50) :

    I’ll be keeping an eye on your volcano forecasts, but I am extremely skeptical ……”

    Piers just said there could be renewed acitvity at his SWIPs around the 18th to 24th April.
    I work with Piers in the Weather Action team, and specialise in temperature variation, and have discovered the connection between temperature rises, and new volcanic activity. I have forecast nearly every period of new activity since November 2008. The recent Iceland eruption fits the theory well, with the eruption occuring on this very warm start to April. Also see this post (09:35:41) for local conditions.

    Iceland volcanoes can actually continue billowing stuff out for weeks, months or even years.

  129. I am fascinated by these posts. I have learned more today about volcanoes (and why ice is slippery!) than I had ever known.

    If an English teacher, venturing into this science blog, may make two requests:

    1. In a comparison, use “different from,” not “different than.”
    2. In an explanation, use “the reason is that…,” not “the reason is because…”

    I could explain the grammar, but it’s not nearly as interesting as volcanoes.

  130. Can someone tell me, just an estimate please, how much of these greenhouse gases are being emitted from the volcano over the last couple of weeks compared to how many vehicles it would take to emit the amount that has been emitted over the last few weeks.

    This comparison is crucial in understanding human impact on global warming versus natural causes.

  131. A little off topic but B.A. and KLM plus the Germans, have been running test flights and finding no damage/problems.

    Nice to note that the aviation shutdown by the air traffic controllers was based on a Met Office model! There are now many claims of over reaction based on the model. Passenger safety versus company profit? Who can tell?

  132. Thanks Steve that’s very useful. I was the one that posted elsewhere about the idea of pressure release. The idea is way older than Scientific American lets on. Funny how warmists never go in for accurate references in these cases. My assumption was that the melt produced increased water that reacted the magma to increase the probability of an explosive release. I see you’ve dealt with that too in the next volcanism post.
    Nice to know I hadn’t missed a post.

  133. If the premise in “Scientific American” is correct, would it not be a “good” thing? Volcanic eruptions and earthquakes will happen eventually. The longer they wait the more intense the event. If this were anything other than “post-modern science” there would be a mention of the potential benefit of letting off a comparatively little amount of steam rather than building to a cataclysmic event. Thinking of earthquakes, would it be less damaging to have a 5.0 earthquake every year for 100 years on the San Andreas, or a 7.0 once every hundred years? (I know the amount of energy released from a 7.0 is more than 100 times the amount of a 5.0, but isn’t the displacement about the same?)

  134. After a bit more research into the interesting geologic structures (Bookshelf and near vertical faulting) that occur in Iceland and the massive rift zone systems, glacial pressure appears to be a reasonable factor. Clearly, the events are driven by magma supply but…

    Geology and geodynamics of Iceland
    R.G. Trønnes, Nordic volcanological Institute, University of Iceland
    source: http://www2.norvol.hi.is/Apps/WebObjects/HI.woa/1/swdocument/1006551/Introduction+to+Geology+and+geodynamics+of+Iceland+-+Reidar+Tršnnes.pdf

    page 13:
    Glacio-isostatic modulation of volcanism
    The low viscosity of the high-temperature upper mantle and lower crust makes the pressure release melting very sensitive to rapid glacial unloading and rebound. The link between deglaciation and increased volcanic productivity has been noted in many different parts of Iceland: the Reykjanes Peninsula (Jakobsson et al. 1978), the Vei•ivötn fissure swarm in the ERZ (Vilmundardóttir and Larsen, 1986), the Askja (Sigvaldason et al, 1992) and •eistareykir (Slater et al. 1998) volcanic systems of the NRZ and the Snæfellsjökull system (Hardarson and Fitton, 1991). The unloading effect leads to nearly 100 times higher volcanic productivity than that of recent times (< 5 ka BP) and during glacial periods (Maclennan et al. J. Geophys Res., submitted).

    The magmas erupted during the periods of maximum productivity in the glacial rebound stages are the most primitive magmas recorded in Iceland. Almost all of the accessible picritic eruption units and most of the large monogenetic shield volcanoes of primitive olivine tholeiitic composition are of early post-glacial age. These relationships demonstrate that the crustal magma plumbing system has inadequate capacity for melt processing during periods of large magma supply from the mantle.

  135. In the early and mid 1980’s I attended several corporate sponsored presentations by a climatologist who related vulcanism to global cooling and predicted significant cooling in coming years. His ideas were based upon geologic history with a bit of astronomical tidal forces thrown in to boot. Anyone out there know of whom I speak? He was in his eighties then and is long gone now.

    By the way, as an engineer and fairly competent statistician my bet after much reading of the various evidence available is that anthropogenic global climate change of any kind is pure bull fecal material.

  136. Jim, pure bull fecal matter causes global warming. The potential increase in geological activity on the other hand will be “climate change”. There are theories that the intensity, and lack thereof, of solar cycles has an impact on Earth’s geological activity. These theories seem at least as credible to me as AGW climate models.

  137. Alan Cheetham (12:37:32) :

    In 2000 the Guardian said the largest glacier would be gone in 5 years – it hasn’t changed much in 10 years.
    For an examination of Iceland climate data, volcanoes and glaciers, including the Guardian’s old claim, see:

    http://www.appinsys.com/globalwarming/RS_Iceland.htm

    —…—…—

    OK. So, let us assume that this “theory” – that global warming caused the Icelandic glaciers to melt, which lowered the pressure on the volcano’s core, which allowed the magma to leap out and spew millions of tons of ash tens of thousands of meters into the air – might be true.

    A few pertinent questions come to mind – that NOBODY has seen fit to ask yet.

    First: Did ANYBODY doing this “Scientific America research” for their article verify that :

    (1) the 1/2 of one degree (maybe !!! – if surface records are correct) of actual global warming since 1970 was actually enough rise in temperature to actually MELT the glaciers worldwide as has been claimed in tens of thousands of articles and IPCC-quoted “research” papers?

    (2) If that 1/2 of one degree of warming was actually enough to melt the glaciers “as consensus claims” – then the ten years of continued constant temperature should be visible in the change of glacier mass.

    After all, we are continuously told that the 25 years of rising temperature caused the glaciers to melt, so a ten year period of constant temperature should be just as visible in the glacier record. (No further increase in glcier melt, no change in glacier melt rate -rather than an accelerating glacier melt rate as (assumed !!!) between 1973 and 1998, etc….)

    (3) Did the one particular glacier atop this particular mountain actually recede as implied?

    We KNOW that only about 1/3 of the world’s glaciers are retreating = therefore, we CANNOT assume that this glacier retreated between the 1973 and 2010, as implied by the article.

    (4) If this one aparticular glacier did actually melt, how much mass was lost?

    No guesses, no wave-the-hands-in-front-of-a-camera and spout Gaea principles of AGW-inspired meltdowns.

    How much glacier mass actually melted, and what was the original mass of rock and stone over the magma, and what caused the previous hundreds of eruptions on this mountain at what frequency? Was THIS PARTICULAR eruption so early that something different (glacier melt) clearly cause it?

    (5) Volcanoes shrink and swell by tens of meters over their lifespans – between the eruptions that (literally !) move mountians hundreds of miles and lift tons of debris thousands of meters.

    What was the trend of this particular vocano’s swell (uplifting) between the hot temrpoatures of the mid-1930’s through the cold period of 1945 – 1973, and the warming period from 1973 through 2010?

    What actual EVIDENCE is there that there is actually ANY change (acceleration or deceleration between any ten year period of that series of measurements – and if there are no measurements, then this whole article is a fantasy – that indicates ice melt might have influenced the swelling of the mountain.

  138. (6) I might include also this question: If this particular glcier melted in the past few years – which has not been verified to date – where did the “melt” occur?

    At the foot of the glacier, with upper regions still about the same?

    Then unless the magma swell was also at the foot of the mountain, the glacier mass had no effect on the magma coming up through the mountain rock higher up. (If anything – a lower mass lower down the slope of the mountain would indicate that the eruption should be sideways – like at Mt St Helens where the side of the mountain slid down, and the ash was blown out sideways, no from the crater at the peak.

    At the peak (upper end of the glacier mass? If so, where was the magma pushing up before and after the glacier melt?

    If it could be claimed to be “general ice mass loss” – then what was the ACTUAL percent of mountain mass compared to glacier mass – before and after the assumed melting?

    How was mountain mass calculated? How was glacier mass estimated? Who – and what agenda did the assumers have – did the estimations of glacier mass loss?

  139. carddan,

    Precession (wobble in the earth’s spin, earth’s orbital shift (the shape of the orbit acually changes over long periods of time) and actual axial inclination change all occur in a cyclical fasion which has been related to geologically historical glaciatians. The amount of solar radiation recieved by the northern hemisphere, in particular, due to these changes can vary significantly, causing heating and cooling. Never heard that these variations had effect on vulcanism, but it would make sense given the changes in tidal forces acting upon the magma which could result.

    In any event, wish I could remember the name of the old climatologist from the 80’s but senility is creeping up on me. The forces of nature are so profound compared to any effects tiny creatures such as man have upon our planet that AGW is nothing more than a trbute to the vanity and dishonesty of very small men in search of the dollar.

    And, yes, the bovine excrement does creat methane, a green house gas but so do private jets, 24000 sq ft houses and all the hot air expelled at conferences discussing such nonsense as AGW.

  140. The greater compression effect is on Antarctica—as ice flows with the loss of lateral support from disintegrating ice shelves, the pressure reduction will eventually allow the pent up energy to explode. melt water will cause sea levels to rise dramatically in a few weeks at most. There is reason to hypothesize that earlier explosions in Iceland in ancient times may be the basis for the accounts in Plato. Hence “ancient” not prehistoric. Ask Noah This has nothing to do with manmade CO2. It is a periodic coinciding cycles–peaking now. Lst time was 720,000 years ago –a 2 cusp cycle–this length interglacial only every 720,000 years. The compression and subglacial expansion can be measured by space-based topo measurement. The weights and pressures can be estimated and the blowup roughly predicted.

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