From the Helmholtz Association Greenland ice is melting — also from below
Heat flow from the mantle contributes to the ice melt
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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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.
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.
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.
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.
The big stink about the loss of the Larson B ice shelf in Antarctica may amuse those who know where steamy Deception Island is:
http://s24.postimg.org/hxyvnocr9/Deception_Island.jpg
The red dots are volcanoes.
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.
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.
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
I sent it twice ,thought it did not go through the first time.
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.
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.
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.
.
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.
David, it is also to premature to say who is correct and who is not.
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.
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.
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.
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…
Back in 2008 we had a similar surprise way south.
Interesting, though the last two paragraphs are not helpful or accurate:
http://phys.org/news/2013-08-lubricating-effect-glaciers-minor-role.html
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?
I thought the red dots were those pesky Greenlander’s SUV’s….
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.
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?
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.