Surprise: Greenland ice gets a melt assist from Earth’s hot mantle below

From the Helmholtz Association Greenland ice is melting — also from below

Heat flow from the mantle contributes to the ice melt

1mantle_melting_ice_greenland

Model of basal ice temperatures in the Greenland Ice Sheet across the summit of the ice sheet. The GRIP and GISP2 are drilled borehole locations. Click to enlarge. Image: A. Petrunin/GFZ

The Greenland ice sheet is melting from below, caused by a high heat flow from the mantle into the lithosphere. This influence is very variable spatially and has its origin in an exceptionally thin lithosphere. Consequently, there is an increased heat flow from the mantle and a complex interplay between this geothermal heating and the Greenland ice sheet. The international research initiative IceGeoHeat led by the GFZ German Research Centre for Geosciences establishes in the current online issue of Nature Geoscience (Vol 6, August 11, 2013) that this effect cannot be neglected when modeling the ice sheet as part of a climate study.

The continental ice sheets play a central role in climate. Interactions and feedback processes between ice and temperature rise are complex and still a current research topic. The Greenland ice sheet loses about 227 gigatonnes of ice per year and contributes about 0.7 millimeters to the currently observed mean sea level change of about 3 mm per year. Existing model calculations, however, were based on a consideration of the ice cap and considered the effect of the lithosphere, i.e. the earth’s crust and upper mantle, too simplistic and primarily mechanical: the ice presses the crust down due to its weight. GFZ scientists Alexey Petrunin and Irina Rogozhina have now coupled an ice/climate model with a thermo-mechanical model for the Greenland lithosphere. “We have run the model over a simulated period of three million years, and taken into account measurements from ice cores and independent magnetic and seismic data”, says Petrunin. “Our model calculations are in good agreement with the measurements. Both the thickness of the ice sheet as well as the temperature at its base are depicted very accurately. “

The model can even explain the difference in temperature measured at two adjacent drill holes: the thickness of the Greenland lithosphere and thus the geothermal heat flow varies greatly in narrow confines.

What does this mean for climate modeling? “The temperature at the base of the ice, and therefore the current dynamics of the Greenland ice sheet is the result of the interaction between the heat flow from the earth’s interior and the temperature changes associated with glacial cycles,” explains corresponding author Irina Rogozhina (GFZ) who initiated IceGeoHeat. “We found areas where the ice melts at the base next to other areas where the base is extremely cold.”

The current climate is influenced by processes that go far back into the history of Earth: the Greenland lithosphere is 2.8 to 1.7 billion years old and is only about 70 to 80 kilometers thick under Central Greenland. It remains to be explored why it is so exceptionally thin. It turns out, however, that the coupling of models of ice dynamics with thermo-mechanical models of the solid earth allows a more accurate view of the processes that are melting the Greenland ice.

###

Petrunin, A. G., Rogozhina, I., Vaughan, A. P. M., Kukkonen, I. T., Kaban, M. K., Koulakov, I. & Thomas, M., “Heat flux variations beneath central Greenland’s ice due to anomalously thin lithosphere”, Advance Online Publication, Nature Geoscience, 11. 08. 2013, http://dx.doi.org/10.1038/ngeo1898)

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79 thoughts on “Surprise: Greenland ice gets a melt assist from Earth’s hot mantle below

  1. “We found areas where the ice melts at the base next to other areas where the base is extremely cold.”

    No you didn’t – you found numbers in your model that you are interpreting to meant this – but you haven’t actually “found” anything physical at all.

    (wow – previews too!)

  2. steveta_uk says:
    August 12, 2013 at 9:09 am

    Yes.

    Moreover, approaching the variables that nobody wants to acknowledge through the back door of modelling is just cheap. Let’s face it, the climate change community is so vested in the single-variable system (CO2) that it will never make the effort to see how much they need to learn about geodynamics.

  3. “The current climate is influenced by processes that go far back into the history of Earth:”
    Yet the word ‘anthropogenic’ has maximum credence for current climate changes.

  4. I wonder if it is possible to “see” under the ice and look for lava flows and spent volcanoes. I am guessing it is not possible to drill 70 km and look at a core of the underlying lithosphere?

    Interesting article but “Our model calculations are in good agreement with the measurements.” is the same mealy mouthed “Corporate News Release” that inspires me to wonder what the agenda of the info is. I have no clue here though…

  5. The GFZ illustration as I read it shows that the warmer [temperature] is near the surface. That seems contrary to what the article is saying. Having been deep underground in a Colorado gold mine I know that was very hot compared to the surface. To me this article is puzzling in terms of it actual surface level effects in the short term.

  6. Not surprising, considering that the core of the earth is hotter than the sun….on the Tonight Show, hosted by Conan O’Brien, the Goreacle sayeth:

    “People think about geothermal energy – when they think about it at all – in terms of the hot water bubbling up in some places, but two kilometers or so down in most places there are these incredibly hot rocks, ’cause the interior of the earth is extremely hot, several million degrees, and the crust of the earth is hot …”

  7. There is nothing new or surprising about this finding. I recall being in Whitehorse in the Yukon back in the 1960s when glaciologists flew in from all over the world because the Donjek glacier began surging. These are generally called “galloping glaciers”. Most often the action is attributed to increased basal slip as a layer of water forms between the ice and the bedrock, usually caused by geothermal heating.

    One reason this issue is avoided is because it speaks to the issue of geothermal heating as a source of energy for the global system, especially under the oceans where the crust is thinnest. This is exacerbated by the crustal warping and deformation caused by the weight of the glacier.

  8. From ‘Denmark’ thread:

    vukcevic says:
    August 11, 2013 at 3:46 pm
    Iceland and the Arctic are unique, there continental plates are spreading out. Magma pouring out to the surface is directly from the Mantle’s convection cell (thermal circulation all the way from outer core- liquid iron & nickel to the Earth’s surface).
    In most of other volcanic areas magma is product of tectonic plates subduction process, with no direct link with convection cells.

    http://www.vukcevic.talktalk.net/Ap-VI.htm

    first posted on WUWT one year ago, almost to a day.

    Leif Svalgaard says:
    August 11, 2013 at 4:26 pm
    So what, the plates are spreading all along the mid Atlantic ridge.

  9. “the warmer tee rapture” – I know what your typo intended, but I’d much rather let the modelers figure out the proper parameterization to get tee rapture right.

  10. 1.August 8, 2013 at 12:51 pm
    2.
    Leif Svalgaard, is in a dream world when it comes to what is currently taken place on the sun and the future climatic implications.

    3.
    Leif has no regard for past history which lends support that the sun is much more variable then what he keeps trying to convey and that the solar conditions during the MAUNDER MINIMUM were very weak(aa index near 0 ,solar wind 200km/sec) and how this correlated to the very cold conditions at that time. In addition he keeps trying to down play the significance of how very very weak solar cycle 24 is and will be going forward.

    4.
    This flip is nothing like a normal flip and I would not be surprised (as the prolonged solar minimum continues due to angular momentum exerted by the planets on the sun, which Leif also says is not correct) that this may be the last flip , or at the very least the future flips are going to be even less pronounced then even this one.

    5.
    Leif, and the mainstream keep trying to play up the fact that the sun is acting the same now as it has all of last century which can not be further from the truth.

    6.
    This cycle could be weaker then solar cycle 5, and is much weaker then solar cycle 14 . Layman sunspot counts and graphs which are correct show this clearly to be the case.

    7.
    The AP index and solar flux going forward will end this debate, and as of today we have solar flux around 105 at the maximum ! It should be north of 150.

    8.
    Also since Oct 2005 the AP index has been extremely low and I expect sub 5 will be the rule in the not to distant future, at least post 2015.

    9.
    Once the solar parameters hit the levels I have been saying (see below) I list the potential secondary effects which could take place as a result.

    10.
    1. solar flux sub 90 but better sub 72, less UV light less ozone more meridional atm. circulation ,more clouds,snow cover and precip.,higher albedo ,colder temp. N.H.

    11.
    2. precipitation patterns changing can impact the thermohaline circulation perhaps slowing it down if precip increases substancially and adds more fresh water to the system.

    12.
    3. solar wind sub 350 km/sec but better sub 300 km/sec, more cosmic rays more clouds ,higher albedo, colder temp. more geological activity especially in high latitudes.the geo magnetic field weakening of earth promoting this even more.

    13.
    4. solar irradiance off .015% less visible light ocean heat content subsides

    14.
    5. ap index 5 or lower with isolated spikes will cause the plates to be more unstable, more volcanic activity and earthquake activity. more shocks to the magnetosphere.

    15.
    6. low solar in addition to being correlated with an increase in major volcanic activity and earthquakes in and around the solar minimums also can be tied to a cold pdo/amo. a cold pdo translates to more la ninas versus el ninos the result global cooling.

    16.
    7. low solar activity having severe impacts to the Thermosphere and Ionopsphere.
    Thermosphere will contract and cool substancially during a prolonged solar minimum which will inter act with all the other layers of the atmosphere.

    17.
    This explanation is the ONLY explanation that can explain the many past abrupt climatic changes of the past both up and down. There are no other explanations from Milankovitch Cycles, to the Thermohaline circulation shutting down, to extra terrestrial impacts,to the sudden increases in greenhouse gases like methane or co2 etc etc.

    18.
    The explanation above shows how the climate could be brought to thresholds if the solar parameters change in degree of magnitude strong enough and for a period of duration long enough following a sufficient number of years of sub- solar activity in general, which no other explanation is able to show.

    19.
    Thresholds have to be met to flip the climate from one climatic regime to another. When the climate is in the same climatic regime changes are gradual and slow and always stay within particular boundaries.

    20.
    I am still waiting for alternative explanations, have yet to see one.

    21.

    22.
    Leave a Reply

  11. No matter how valid the underlying geophysics, there is no way these models are validated or say anything about melting and sea level. The image shows that the hottest modeled ice is still -2C. Melt? And the image shows two basal ice sheet data points, GRIP and GISP2. Although two points suffice for a trend line, it takes a minimum of three to begin to validate that line.
    At least the study is better than most climate science, which seems to use only one datapoint and a theory to anchor projections. Unless it is Trenberth’s missing heat, in which case theory alone sufficed.

  12. There’s an inherent hazard in trusting or distrusting “models” that is often ignored in all the sciences. Looking at the preview there are several important facts that help determine the reliability of the results and are important. The chief one is how the “Curie point” or transition point depth is estimated. It is estimated from data collected by measuring regional magnetic field strength. Since hotter materials will have weaker magnet field strengths, and will lose magnetic field below the transition, you can estimate depth below surface of the transition point if you have a good idea of the mineralogy involved, since a cold hunk of the rock can retain a magnetic field of a strength limited by the mineralogy of the rock. If you have the mineralogy, you can also provide a good estimate of thermal conductivity in the regional crust.

    Depth of transition point, related to base of ice sheet gives a thickness of the lithosphere and geothermal heat flow can be modeled from the two surfaces. The estimated Curie point depths in the region provides one surface and the sounding of the ice sheet provide the other. That is far more straightforward than “feed backs” and “forcings.”

    The essential conclusion of the article is that current climate models dealing with the ice sheets are too simple, which sceptics have been arguing all along.

  13. Dear Sir,

    There is considerable excitement among the Green activists because it seems that the Greenland Ice Sheet is melting. This, they claim, is proof positive that we are now seeing the results of Global Warming due to man.   However, in the year 982 AD a rather turbulent Viking Erik the Red sailed west and found a green land which he called ‘Greenland’. He then began to colonise Greenland. It was then green with grass and virtually no ice. Over next four or five hundred years the colony built up to over 4000 – 5000 people with over 150 farms and was more or less self sustaining. The ice returned at the beginning of the Little Ice Age and the colony then failed. During this period there were no factories, central heating or other significant sources of man made CO2.   Why the fuss and claim that the current loss of ice in the northern hemisphere (but not in the Antarctic) is due to man?   Mick G

    ________________________________

    • Are you saying “virtually no ice” anywhere in Greenland, or only along the southeastern coastline where the to settlements were established, as I has always understood the case to be?

  14. “This conclusively proves that it is All George Bush’s Fault.”

    George Bush’s Fault. Is that some place where the Pacific and North American plates collide?

  15. It’s worse than we thought!

    Science – 14 December 2001
    Abstract
    Age-depth relations from internal layering reveal a large region of rapid basal melting in Greenland. Melt is localized at the onset of rapid ice flow in the large ice stream that drains north off the summit dome and other areas in the northeast quadrant of the ice sheet. Locally, high melt rates indicate geothermal fluxes 15 to 30 times continental background. The southern limit of melt coincides with magnetic anomalies and topography that suggest a volcanic origin.

    http://www.sciencemag.org/content/294/5550/2338.short

    Below is Co2 Science’s comment and quotes from the full paper I presume.

    The authors note that free-air gravity measurements over the primary area of basal melting and the high geothermal fluxes experienced there are comparable in magnitude and spatial extent to those of the Yellowstone caldera, and that localized peaks in gravity and rough-surfaced bed topography are suggestive of local extrusive structures. Hence, they conclude that their “limited geophysical evidence suggests the presence of a caldera structure,” which leads to “rapid and extensive basal melting in Greenland that has a direct effect on ice flow.”

  16. Salvatore Del Prete (10:01 am) exactly what has this extended whinge about your dislike of Dr. Svalgaard got to do with geothermal modelling?

  17. Doubt the models, as usual but there’s high probability that we’ll see a “study” soon claiming the warming of the underlying rock is somehow influenced by CO2.

  18. steveta_uk says:
    August 12, 2013 at 10:34 am
    Salvatore Del Prete (10:01 am) exactly what has this extended whinge about your dislike of Dr. Svalgaard got to do with geothermal modelling?
    Pseudo-scientists, alarmists, and agenda-driven people will use every forum they can to peddle their nonsense [on topic or not]; there has already been a couple of comments of this ilk on this very thread – expect more.

  19. This falls into the caregory of “iignore geology & geologic history at your own peril when studying climate ”

    We have seen this theme in many posts on WUWT, as well as elsewhere.

  20. I’ve wondered for a long time about how we could model ocean heat content without a good accounting of the number and size of undersea heat sources. I used to work as an IT contractor for NOAA on the Integrated Ocean Observing System effort (IOOS). As conferences came and went, I’d ask our academic and government experts if anyone had a good accounting of such heat sources. ‘Never found anyone who knew of any existing global tracking of such things. Since then, from time to time, we hear that there are undersea volcanoes in the undersea ridges running up into the Arctic. And, they are active. ‘Shouldn’t be a surprise, should it? Now, we hear that underground heat might be effecting on top of ground ice? Amazing!

    The fact that these enormous pieces of this global heat exchange system are so completely unknown means that our global climate models don’t stand a pico-glacier’s chance in hell of being useful.

  21. I’m surprised by all the negative comments. What this study says is that the amount of melting blamed on CO2 by climate models is too high. Their “model” isn’t a model in the same sense that the climate models are, and the output has a correlation to actual temperature variations that seems rather accurate (based on the claims in the abstract).

    So a study comes out showing that CO2 is NOT to blame and everyone jumps on it because it has the word “model” in it.

  22. I don’t dislike Leif at all. I do however think there is a great need to educate the public at large that there are many sides to this climate puzzle besides the opinions of the likes of Leif and the theory of AGW.

    Both of which I feel strongly are not correct and in the case of the AGW theory, it is based on complete utter falsehoods, ranging from no lower troposheric hot spot, to the atmospheric circulation becoming more meridional rather then zonal,from the lack of any temp. rise for 17 years, to the lack of any pronounced stratospheric cooling, to the lack of more El Ninos, just to highlight a few of the many items this theory has based itself on that have failed to take place. occur.

    But I have nothing against Leif , and wish him well.

  23. The big stink about the loss of the Larson B ice shelf in Antarctica may amuse those who know where steamy Deception Island is:

    The red dots are volcanoes.

  24. Salvatore Del Prete says:
    August 12, 2013 at 11:04 am
    I do however think there is a great need to educate the public at large that there are many sides to this climate puzzle
    You do, however, not educate the public in any way, just hijack threads to peddle your personal unsubstantiated opinion.

  25. This article about Greenland is a non issue, and the last I heard the Greenland Ice Sheet was well intact, and like the Arctic Sea Ice will not be going away.

    Just another ploy to to advance the hoax of AGW.

  26. Leif just because I don’t agree with you (as do many others) does not mean that we have no basis for our opinions.

    I can name many who have the same basic beliefs as I do. Just to name a few,look below.

    Leif is wrongly trying to make it seem like I am the only one, which is not true in the least.

    David Archibald
    Piers Corbyn
    Joe Bastardi
    Joe D’aleo
    Don Easterbrook
    Robert Felix
    Tim Ball
    Geoff Sharp
    Ian Wilson
    Nicholas Scafetta
    Henry Sevensmark

  27. We don’t need to worry about bottom melt adding to sea level. Greenland’s interior is bowl shaped, with the ground level in the area of the study depressed 200+ meters below sea level.

  28. Salvatore Del Prete says:
    August 12, 2013 at 11:28 am
    >>>>>>>>>>>>>>>>

    A list of people who agree with you is meaningless. If that were a valid criteria, then the climate debate would be over.

    When asked to substantiate his assertions, Leif provides the data to do so. All I hear from you is yammering.

  29. Salvatore Del Prete says:
    August 12, 2013 at 11:28 am
    Leif just because I don’t agree with you (as do many others) does not mean that we have no basis for our opinions.
    ‘We’ ? So you are the spokesman of a motley crew of believers?

    Leif is wrongly trying to make it seem like I am the only one, which is not true in the least:
    David Archibald, Piers Corbyn, Joe Bastardi, Joe D’aleo, Don Easterbrook, Robert Felix, Tim Ball, Geoff Sharp, Ian Wilson, Nicola Scafetta, Henry Svensmark…

    Some of those people hardly count as knowledgeable people and I suspect some will object to be recruited into your cult of like-minded.

    • The study seem to show a phenomenon that has been going on for millions of years, and if so, then it is no short term value in re the near term (out to 2100ad) climate debate. Climate ignorati may say otherwise but they live in a separate bull-silliness reality.

  30. .
    Leif provdes the data but does not know how to look at it properly.

    Many of us view the same data and reach entirely different conclusions.

    If however you think otherwise and want to follow someone follow him, since it looks like you made up your mind he can do no wrong,and what ever he says is correct and there is NO room for divergent opinions.

    • @Sal – as AGW has shown us, you can look at any data and support your conclusion. However the object is not to support your conclusion. The object of studying data is to see where it leads, not where you want to lead it.

  31. David one last thing, it REMAINS to be seen if my data and thoughts will pan out,since the parameters(the data) I called for and duration of time have yet to take place,although I think they will as this decade proceeds.

  32. Salvatore Del Prete says:
    August 12, 2013 at 12:00 pm
    David, it is also to premature to say who is correct and who is not.
    >>>>>>>>>>>>>>

    I made no claim in this regard.

  33. Salvatore Del Prete says:
    August 12, 2013 at 12:04 pm
    David one last thing, it REMAINS to be seen if my data and thoughts will pan out
    >>>>>>>>>>>>>>>>>>

    There are three possibilities:

    1. Temps will increase
    2. Temps will decrease
    3. Temps will remain the same

    Regardless of which one proves out over time, a great number of people will claim they knew it all along and were “right”. Most of them will be right for the wrong reasons. As for your data, you haven’t presented any, either to refute Leif’s position or to support your own.

  34. philjourdan says:
    August 12, 2013 at 9:31 am
    So how do they blame CO2 for the heating of the mantle?
    ==========================================================

    Reason has never prevented such inanity before. Try hard enough and anything can be linked to global warming. We’re talking a belief system here, not science.

    http://www.numberwatch.co.uk/warmlist.htm

    AIDS, Afghan poppies destroyed, African holocaust, aged deaths, poppies more potent, Africa devastated, Africa in conflict, African aid threatened, aggressive weeds, Air France crash, air pockets, air pressure changes, airport farewells virtual, airport malaria, Agulhas current, Alaskan towns slowly destroyed, Al Qaeda and Taliban Being Helped, allergy increase, allergy season longer, alligators in the Thames, Alps melting, Amazon a desert, American dream end, amphibians breeding earlier (or not), anaphylactic reactions to bee stings, ancient forests dramatically changed, animals head for the hills, animals shrink, Antarctic grass flourishes, Antarctic ice grows, Antarctic ice shrinks, Antarctic sea life at risk, anxiety treatment, algal blooms, archaeological sites threatened, Arctic bogs melt, Arctic in bloom, Arctic ice free, Arctic ice melt faster, Arctic lakes disappear, Arctic tundra lost, Arctic warming (not), a rose by any other name smells of nothing, asteroid strike risk, asthma, Atlantic less salty, Atlantic more salty, atmospheric circulation modified, attack of the killer jellyfish, avalanches reduced, avalanches increased, Baghdad snow, Bahrain under water, bananas grow, barbarisation, bats decline, beer and bread prices to soar, beer better, beer worse, beetle infestation, beef shortage, bet for $10,000, big melt faster, billion dollar research projects, billion homeless, billions face risk, billions of deaths, bird loss accelerating, bird populations dying, bird strikes, bird visitors drop, birds confused, birds decline (Wales), birds driven north,und so weiter…

  35. Back in 2008 we had a similar surprise way south.

    Surprise! There’s an active volcano under Antarctic ice
    ……Scientists have just now discovered an active volcano under the Antarctic ice that “creates melt-water that lubricates the base of the ice sheet and increases the flow towards the sea”.
    WUWT

  36. philjourdan says:August 12, 2013 at 9:31 am

    So how do they blame CO2 for the heating of the mantle?

    Trenberth’s missing heat?

  37. slightly o/t.one of the arguments i provided in a long debate with a member of the skeptical science team on a non climate related forum centred around the lack of knowledge on just how many active underwater volcanoes there were and their contribution to co2 emissions.

    i was assured the volcanoes and their emissions were all documented and taken into account.
    when i questioned this i was told it was fact. it was news to me we have now documented every square metre of the sea bed.

  38. Assuming the Greenland sheet to be in equilibrium with the steep geothermal gradient (maybe/maybe not), only changes in the geothermal gradient would be relevant to growth or decay of the ice sheet. Is my thinking off on this?

  39. vukcevic says:
    >Iceland and the Arctic are unique, there continental plates are spreading out.

    Leif Svalgaard says:
    So what, the plates are spreading all along the mid Atlantic ridge.

    meemoe_uk says :
    All continental plates are spreading out all the time. And all oceanic plates too.

  40. Salvatore Del Prete says:
    August 12, 2013 at 11:28 a
    ————————————-
    Wow, it appears you have a consensus of belief. That is so wonderful…
    Now lets dance…

  41. All this wondering this and wondering that. It is no coincidence that nearby Iceland, built from material flowing out of the Mid-Atlantic Ridge, is entirely a volcanic island and has fantastic volcanoes and hot springs. Iceland land surface is continually growing by accretion of offshore volcanoes. It keeps their surveyors busy mapping new land. It is one of the few places on earth where one has volcanic eruption under ice. The flat-topped volcanoes called tuyas are a result of this and are an interesting sight there.

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

    We’ve been recently treated to several “surprising” discoveries of active undersea volcanoes in a line going north of Iceland passing near Svalbaard and all the way up to 85N. Why would we think a feature that goes down the mid-Atlantic all the way past the southern tips of Africa and South America would not extend a few hundred km more north. In fact these are surprise new discoveries for non-geologists. I see this kind of knowledge “new” to climatologists all the time. Learning by doing can be rewarding but to report on it the way they do makes asses out of themselves. Here even Wiki has something on it. These egghead institutes should call up the geology department of a nearby university, first.

  42. meemoe_uk says:
    August 12, 2013 at 3:14 pm
    “All continental plates are spreading out all the time. And all oceanic plates too.”

    Really? So the Earth’s surface is growing?
    I love this thread, i am always learning new things.
    I thought only the Antarctic plate was the only plate that was growing all the time…

  43. Here is a nice profile of the temperature of the Greenland glacier from top-to-bottom at the Summit (GISP2) site.

    http://www.iceandclimate.nbi.ku.dk/images/images_research_sep_09/Temp.jpg/

    At the bottom of the ice in most of Greenland, the temperature is around -2.4C, which is just enough to melt the ice given the additional pressure of the ice above. The ice temperature is a balance of the “memory” of when the snow fell at -35C for example, got buried and is now deeper versus the heat coming up from the bedrock below. This means that throughout Greenland, they can’t really resolve any ice older than 115,000 years ago because it has mostly melted already and/or is too distorted to get an accurate age estimate.

    The new NEEM ice core from northern Greenland, however, was just slightly colder at -3.0C and has allowed ice core data back to 130,000 years ago.

    [just a personal comment about this temperature profile. It is used in borehole thermodynamic modelling to estimate the temperatures that might have existed at the surface when the snow fell. This model is then applied to the dO18 isotope data to arrive at the temperature history in Greenland going back to 130,000 years ago. I think this methodology is faulty. It comes up with a change in temperature from the last glacial maximum in Greenland of 25C while the global temperature change was only 5C. Antarctica is only 10C (given a realistic polar amplification factor of 2 times). I don't believe polar amplification in Greenland is 5 times and this borehole thermometry modelling has led to incorrect estimates about Greenland's temperature history. And this means it applies to the GISP2 temperature charts which you may have seen on the internet. Cut the temperature change by 2.5 times to reflect the real temperature in Greenland or cut it by 5 times to reflect the global temperature reality. Just a personal comment that a few other scientists agree with (as in all those assessing Antarctica ice cores) but most Greenland ice core scientists don't agree with].

  44. The current climate is influenced by processes that go far back into the history of Earth: the Greenland lithosphere is 2.8 to 1.7 billion years old and is only about 70 to 80 kilometers thick under Central Greenland. It remains to be explored why it is so exceptionally thin.

    Isn’t it obvious? Without the ocean’s buffering mechanisms, the elevated atmospheric CO₂ and the sulfurous emissions from coal-burning North American power plants have combined for catastrophic Glacier Acidification!

    The meltwater under the icecap must have eaten away the lithosphere!

    And now that the lithosphere is so dangerously thin, Vuk’s graphs can now show an upcoming solar disturbance could rupture the crust under Greenland, leading to rapid icecap loss and Cataclysmic Global Flooding.

    Hansen may have been right, burning all that coal may have been a bad thing after all.

  45. Kajajuk says:
    August 12, 2013 at 4:35 pm
    “All continental plates are spreading out all the time. And all oceanic plates too.”
    Really? So the Earth’s surface is growing?

    No, because an equal amount of area is sinking into the Earth in other places [called subduction zones -Google can explain what those are]

  46. In any case, crustal heat flow doesn’t vary over time scales less than millenia. Whatever heat is coming up from under Greenland has been doing so throughout the last several glacial/interglacial cycles. There is no applicability to changes in melting over decades or even centuries.

  47. Thanks Lief.
    If you know, could you answer a question that no one has yet or any research binge has revealed:
    Why is there no East-West subduction margins to balance the plate spreading of the Antarctic plate from South America to Africa? Is the Earth deforming into a split pear?

  48. Kajajuk says:
    August 12, 2013 at 8:30 pm
    If you know, could you answer a question that no one has yet or any research binge has revealed: Why is there no East-West subduction margins to balance the plate spreading of the Antarctic plate from South America to Africa?
    The Americas are, indeed, for now intruding into the Pacific Ocean floor. What happens next is anybody’s guess. Here is one such guess http://www.youtube.com/watch?v=uGcDed4xVD4 the Pacific seems to get the upper hand, and in 250 million years all continents might be collected in one large landmass, as has happened about 8 times over the history of the Earth.

  49. Also, if you look at the floor of the Arctic one can see three ridges; a very pronounced one, Lomonosov, is 1800 km and i assume dormant. This suggests that that the top of the world has been spreading for a very long time. The gakkel ridge is the active one.
    Where is the subduction to conserve the spreading.

    And all the plates are moving away from the Antarctic Plate:

  50. Leif Svalgaard says:
    August 12, 2013 at 8:55 pm
    —————————
    Cool video.
    If i could have afforded to go to University i would have wanted a time generous prof like you.
    Thanks again!

  51. Kajajuk says:
    August 12, 2013 at 8:57 pm
    And all the plates are moving away from the Antarctic Plate
    Over the long haul all the plates will collect in a super landmass, then drift apart again, then collect, the split, then collect, then split, etc, so any specific tendency in one of the splittings will not survive into the next and all will wash.

  52. Kajajuk says:
    August 12, 2013 at 9:03 pm
    If i could have afforded to go to University i would have wanted a time generous prof like you.
    Thanks again!

    You are welcome. Education is my pleasure and the internet [when you filter out all the nonsense] is a great tool for this.

  53. Goldie says:August 12, 2013 at 6:16 pm
    what evidence do we have that the heat flux from the lithosphere has changed?

    Do we have evidence that it is constant?

  54. Leif Svalgaard says:
    August 12, 2013 at 8:55 pm

    You are a scholar, teacher & gentleman for you patience. The video is fun, but its misuse of “era” for “period” & “epoch” is annoying.

    Here is one scenario for the next supercontinent, assuming continued westward movement of North America, for further collision with Eurasia:

    http://www.livescience.com/18387-future-earth-supercontinent-amasia.html

    But it’s also possible that Atlantic seafloor spreading will stop & possibly reverse, leading to a replay of Pangaea. But in any case, Baja California & Alta California south of Point Reyes will in about 50 million years be a very scenic, long island off the coast of the Pacific Northwest.

    Viewing of the Perseids spoiled locally by a thunderstorm tonight. Darn global warming! I mean climate change! I mean greedy humans!

  55. David M. Hoffer,

    I’m so glad you posted (esp. 10:59AM). I thought the same thing. Whether it intends to or not, the article refutes human-CO2 global warming. That would make it an article to applaud or at least give a little nod to, not to boo and hiss at. Glad someone else thought the same (and someone much more well-versed in science than I).

    Janice

    *********************************
    @WWUT folks: PLEASE FORGIVE THE FOLLOWING NOTE — nowhere to post such things… Thank you, everyone –

    Dear Kevin Knoebel,

    I’m so sorry about the accident. God does whatever he pleases. He allowed a jerk to use his free will to ram into you. He has, nevertheless, promised to “work all things together for good for them who love Him… .” (Romans 8:28). You may hate God, but I love Him. I will keep on praying for you. In fact, I just prayed that He will give you a Chevy Suburban (in good condition, incl. AC and a nice step for your mom to help her get inside) to replace the Jeep. Lest this little note embarrass you, I pray for lots of WUWT people (no need to feel I’m trying to be too friendly, I mean).

    And I won’t write notes like this anymore to you.

    Well, take care, back there (lol, I thought you were in S. Cal or Texas!).

    Your sister in the fight for Truth in Science,

    Janice

  56. Not new science. Geothermal heat average is 30W/m2 which will not melt much ice, and not caused by CO2. (before some idiot jumps onto that scenario)

  57. [i]>If i could have afforded to go to University i would have wanted a time generous prof like you.[/i]

    Leif is far from perfect. He’s a stubborn conservative of 20th century science who has no time for ideas that have been recently evidenced better than the older or more conventional theories. He’s the most knowledgable prof on solar oberservation I know of who is highly active in our community, but his models are outdated. Knowledge without correct interpretation is way short of understanding.

    Here, wrt geology models he’s just grabed with blith faith the flawed current mainstream theory and I expect he’ll give it his full unquestioning support. Someone who does that has no business in science, but he should get a job with the church.

    Well here’s a vid that does some weighing up evidence which conventional continental drift theory can’t explain.

  58. From Janice Moore on August 12, 2013 at 10:22 pm:

    I’m so sorry about the accident. God does whatever he pleases. He allowed a jerk to use his free will to ram into you.

    It is a prerequisite for the exercise of free will to allow others to be acted upon. This ain’t a holodeck simulation.

    You may hate God, but I love Him.

    Why would I do that?

    Janice, I have lived a strange life, with large amounts of forced accidental spirituality. I could go on for several pages of what has happened, of what I have rationally and logically come to accept, by the preponderance of evidence that was not documented, is not reproducible, but which I know was real.

    And this is not the place for it.

    So let me say instead, that a young moron needed a wake-up lesson, I was available and could be in the right place, at the right time, in the right vehicle. And while I had plans to go elsewhere, I was there then. The lesson was taught, I am merely temporarily inconvenienced, there were no serious injuries or deaths, as there could have been with a different vehicle, and perhaps a different driver with possibly passengers.

    I don’t mind doing my part when called.

    I could no more hate God than I could hate the global atmosphere. I am surrounded, sustained, it is within me as I dwell within it, as I willingly breathe it in and into my being. I would perish without it. The analogy breaks down when I will inevitably be done with wearing the flesh, and I will be joined with only one for the transition.

    And I won’t write notes like this anymore to you.

    Personally I don’t mind, the management and other patrons of this fine establishment may think otherwise.

    In fact, I just prayed that He will give you a Chevy Suburban (in good condition, incl. AC and a nice step for your mom to help her get inside) to replace the Jeep.

    On further examination, the gas tank wasn’t what was hit. That’s the spare tire well, which is now so pushed in the spare sticks up, the cover panel inside won’t sit flat to the floor. Frankly, I would consider buying a vehicle like that, and just pound out the well and live with the torn-up bumper plastic, for maybe a third of the cost.

    As it is, the Jeep is drivable, it will be fixed on his insurance. Which is the best case possible, as I’d rather not get a rental even if his insurance is paying for it. As I’d have to get the rental insurance, as I don’t have collision/comprehensive, thus I’m not covered if I damage the rental, and I would pay for the rental insurance, not him.

    BTW, are you watching the national news? The mystery of the priest who showed up at the car wreck, said comforting things, then disappeared into thin air without appearing on virtually all of the photos, has been solved. He’s come forward, his name is Dowling.

    And so goes another Father Dowling Mystery.

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