Zorita on Sea Level

Eduardo Zorita has an interesting post at Klimazweibel containing a very counter-intuitive analysis on the impact of melting of Arctic ice caps on northern hemisphere sea level.

Drawing on Mitrovica et al, Nature 409, 1026 (2001), he observes that ice caps have a gravitational influence on sea level. Should the Greenland ice cap melt, this effect would apparently largely offset volume increase in the NH – the impact would be felt on SH sea levels.

Conversely, NH sea levels would be most affected by Antarctic ice cap loss.

I haven’t made any attempt to examine the data – merely noting an interesting post.

68 Comments

  1. Posted Jun 25, 2010 at 10:15 AM | Permalink

    It’s a very interesting article – I should read Eduardo’s blog. Thanks for the link, Steve! I am going to do the calculations of the shape in Mathematica.

    Steve: Yes, I’m going to refer to it more often. They have some interesting posts on Lysenko, about whom they make the following statement that is amusing in the context of tree ring reconstructions of past temperature:

    In the early 1930s [Lysenko's] research on the developmental physiology of cultivated plants, especially grain, attracted much scientific attention, nationally and internationally. Effects of temperature and light on growth and flowering of plants was a pioneering field considered to have great practical potential.

  2. Tim Channon
    Posted Jun 25, 2010 at 10:34 AM | Permalink

    Maybe but a fact which is often ignored is the earth is not a hard sphere but a squishy ball of liquid covered in floating dross called a crust.

    You take a large mass off Greenland or Antarctica the plug of land will pop up. (nice conundrum on gravity)

    This also means somewhere else has to pop down.

    The thinnest crust is supposedly the ocean floor and that is likely to move.

    Overall effect on notional ocean level? Worry if someone says they are certain.

    • Craig Loehle
      Posted Jun 25, 2010 at 11:10 AM | Permalink

      Exactly correct, but it takes a very long time for the rebound. Scandinavia is still rebounding from removing ice 15000 yrs ago. It is a very viscous material, the mantle.

      • BillyBob
        Posted Jun 25, 2010 at 12:11 PM | Permalink

        I always like this rebound story:

        “As the glaciers here melt, the land is rising, causing the sea to retreat.
        did not exist when his family settled in the area 50 years ago.

        Morgan DeBoer, a property owner, opened a nine-hole golf course at the mouth of Glacier Bay in 1998, on land that was underwater when his family first settled here 50 years ago.

        “The highest tides of the year would come into what is now my driving range area,” Mr. DeBoer said.

        Now, with the high-tide line receding even farther, he is contemplating adding another nine holes.

        “It just keeps rising,” he said.”

        http://www.nytimes.com/2009/05/18/science/earth/18juneau.html?_r=1&em&exprod;=myyahoo

        • Posted Jun 25, 2010 at 9:05 PM | Permalink

          This kind of thinking is why people are now all up in arms about rising sea levels. We don’t learn.

        • D. Patterson
          Posted Jul 6, 2010 at 2:50 AM | Permalink

          The region is subject to uplift resulting from a combination of glacial rebound from the Wisconsin glaciation, local deglaciation, and tectonic uplift along the local portions of the Queen Charlotte-Fairweather transform fault system. This uplift has been measured at the tidal guages since 1919 and earlier. The portion of the uplift due to the tectonic fault activities is undetermined at the present time.

          Neal, Edward G. and Host, Randy H. Hydrology, Geomorphology, and Flood Profiles of the Mendenhall River, Juneau, Alaska. U.S. Geological Survey, Water-Resources Investigations Report 99-4150, Prepared in cooperation with the Alaska Department of Fish and Game and City and Borough of Juneau.

          Hicks, S. D., and W. Shofnos (1965), The Determination of Land Emergence from Sea Level Observations in Southeast Alaska, J. Geophys. Res., 70(14), 3315–3320, doi:10.1029/JZ070i014p03315.

      • Tom Gray
        Posted Jun 25, 2010 at 12:53 PM | Permalink

        If we relate this to a humna time scale, would it make much difference. How long would thse adjsutments take? Wouldn’t it be very likely that our current civilization would be dead and forgotten by then?

      • Sean
        Posted Jun 25, 2010 at 1:47 PM | Permalink

        The rebound is so predictable that I was once able (for a college paper) to calculate the thickness of the sheet by the rate of rebound and the as yet remaining depression of the crust into the mantle.

        I was able to calculate the depression by satellite measurements of gravity, and the minute variations between gravity as measured directly above Scandinavia and the world-wide mean.

        If I remember correctly, gravity is lower at/above scandinavia because crust is less dense and it displaces more dense mantle.

        Perhaps, over a couple thousand years, the recovery of the crust would increase gravity measured at Greenland enough to more than offset the lack of ice?

    • tty
      Posted Jun 25, 2010 at 4:03 PM | Permalink

      It is not as simple as that. What happens when an ice-sheet forms is that the weight of the ice causes a depression to form underneath while tha displaced material flows out an forma a “forebulge” around the ice.
      When the ice melts the displaced material slowly flows back, the depression rises and the forebulge subsides. However thid is a rather slow process, since the interior of the earth is very viscous. It is still in full flow about 12,000 years after the end of the last glaciation, and it will probably not have time to finish before the next glaciation.
      In the “far field” beyond the forebulge the only net effect on sea-level is from the varying amount of sea-water. Just how far from the ice this “far field” starts is much disputed, it depends on the viscosity of the Earths interior, which is very uncertain.

  3. Posted Jun 25, 2010 at 11:33 AM | Permalink

    I just made the full-fledged calculation in Mathematica.

    Indeed, if the average sea level rise is 7 meters, the rise of the sea level at the antipodal point would be around 8.3 meters.

    However, near the center of Greenland, the sea levels would actually drop. Imagining the Greenland ice (today) as a mass point, the sea level rise would be zero about 1,700 kilometers from the center of this ice.

    Below 1,700 kilometers, the elevation would be negative, and it would behave as -1/D for a very small distance D. The simple formula implies about 25 meters of sea level drop at the distance of 1,000 kilometers.

    Of course, the point mass approximation can only be trusted if D is kind of greater than the actual radius of the ice – around 1000 kilometers.

    However, it’s still clear that Iceland, which is only 1,000 kilometers from the center of Greenland, would see its sea level decrease. The Western European beaches which are about 3,000 km from the center of Greenland would experience about 4 meters sea level rise.

    The full text with graphs will be completed at:

    http://motls.blogspot.com/2010/06/if-greenland-melted-sea-level-in.html

  4. Hu McCulloch
    Posted Jun 25, 2010 at 1:45 PM | Permalink

    Eduardo Zorita has an interesting post at Klimazweibel

    In fact, Zorita’s blog is Klimazwiebel, which means Climate Onion. Note the graphics.

    This is a clever play on words because of its similarity to Klimazweifel, which would mean Climate Disbelief. That would get him on the PNAS blacklist, but who could ever object to a Climate Onion? In any event, the climate is a surely multi-layered, complex entity.

    A very interesting post!

    • Posted Jun 26, 2010 at 11:43 AM | Permalink

      It’s Klimazwiebel, and not Klimazweibel. Actually, Klimazwiebel blog is by Hans von Storch, and Eduardo is a frequent guest writer – if I’m not mistaken.
      Maybe it’s called Climate Onion because it makes some readers cry.

  5. Richard
    Posted Jun 25, 2010 at 3:44 PM | Permalink

    Let me dare a further speculation:
    If all Greenland’s ice melts, most of it will stay right there like in a giant bathtub.
    In Antarctica, about 50-60% will stay in case of the average -40C comes close to zero. That is 90% of the world’s ice.
    Please, anyone let me know how much off target I am, by looking at these charts:

    http://nsidc.org/data/atlas/news/bedrock_elevation.html

    http://nsidc.org/cgi-bin/atlas_south?zoomdir=0&zoomsize=2&zoom_to=&glossary_term=&layer=south_pole_magnetic&imgxy=250.0+250.0&imgext=-2618837.675355+-2781162.324645+2781162.324645+2618837.675355&layer=land&layer=coastlines&layer=copyright&layer=antarctica_bedrock_elevation&layer=&layer=&layer=&layer=

    Many thanks

    • tty
      Posted Jun 25, 2010 at 4:16 PM | Permalink

      No it won’t. The “bathtub” in central Greenland is rather shallow. It would become either a lake with a maximum depth of a few hundred meters, or possibly an equally shallow inland sea with a narrow strait to the west (which would in that case probably become a lake after a few hundred years, due to isostatic rebound).
      A complete melt of Greenland Ice by the way is not in the cards even during extreme climatic warmth since Eastern Greenland is a highland with tops up to 3300 m a s l.

      The 50% figure for Antactica only applies to Western Antarctica, which incidentally means that Western Antarctica woul not contribute more to a sea-level rise than Greenland, even if it melted completely (which it can’t since parts of it consists of up to 5000 meter high mountains).
      Eastern Antarctica is too high for major flooding. There would be a major, but rather shallow embayment in the Wilkes Basin and a rather smaller but deeper one south of Prydz Bay, the rest of East Antarctica would remain dry land except for a coastal strip.

      • Richard
        Posted Jun 25, 2010 at 4:49 PM | Permalink

        Thanks for your post.
        Although both of my charts show very little below sea level, I was further intrigued by this Month’s National Geographic.
        It is not how deep and shallow it seems in the center—below sea level, but how high the bedrock’s perimeter specially in Greenland’s case.
        Now, East Antarctica has the real bulk of the ice. Near Vostok ice goes up to 4400 m and also below sea level where it is above freezing point—with water below.

        7 m of sea level rise is a number thrown around by calculating the entire ice volume.
        Is it deducted by how much is going to stay there anyway?

        My question is in a small way to call on experts to challenge the numbers of volume and sea level rise out there. Fear is the great motivator of alarmists.

        Does anyone know how much % of melted ice would stay in Greenland, and Antarctica?
        Consider that whatever ice melts and stays the weight is approximately the same, thus the concavity would stay for very long—for that amount that stays.

        • tty
          Posted Jun 25, 2010 at 5:16 PM | Permalink

          I have tried to calculate it for Western Antarctica and it came out as about 50%, and other have apparently come to about the same result, since this is implied by the 7 m sealevel rise usually claimed for a complete melt of Western Antarctica. There is a lot of uncertainty though, since the subglacial topography is only approximately known.
          For Greenland and Eastern Antarctica the proportion is much smaller, almost certainly <10% for Greenland.

        • tty
          Posted Jun 25, 2010 at 5:32 PM | Permalink

          There is a good map of the subglacial bedrock topography of Greenland on p. 10 of this paper:

          http://www.geus.dk/publications/bull/nr14/nr14_p01-13_A1b.pdf

          From this it can be seen that the “inland sea” would be at the most slightly higher than sea-level, and mostly only a few hundred meters deep.

        • Robert
          Posted Jun 25, 2010 at 10:23 PM | Permalink

          Bamber et al. 2009 also refer to this subject quite extensively and conclude that the likely resultant sea level rise would be near 3.4 meters if a collapse occurs. To clarify, if a collapse occurred it would be on the WAIS and would have very little to do with melting. The hypothesized scenario would be the result of inland migration of the grounding line in the amundsen sea embayment from a location where the bedrock is grounded below sea level and slopes towards the interior (Schoof 2007). This process would hypothetically result in increased ice discharge because of the thickening ice further inland (vaughan 2008). It has been argued that Thwaites and Pine Island Glaciers (also smyth glacier) could be locations where this mechanism could begin. Bamber et al. 2009 also show that if this collapse occurs the regions most affected because of the change in gravitational pull would be the northeastern united states…

        • Sam NC
          Posted Jun 26, 2010 at 4:55 AM | Permalink

          Sea water level rise: 7m, 3.4m or 1.5m?

          Is there a laughable “consensus”?

        • Robert
          Posted Jun 27, 2010 at 1:54 PM | Permalink

          Science Improves over time buddy. Predictions change. The most recent study has indicated that it would be 3.4 meters for a collapse of West Antarctic Ice Sheet. Just because people used to think it was 7 meters does not mean you are being “lied to” it means that with new technology we are better able to understand the topographic constraints on ice sheets. Dr. Bamber is a very well respected Glaciologist and there is nothing “laughable” about his new findings. And for the record, Pine Island Glacier in itself has the ability to cause 1 meter rise if not more so your reference to 1.5 meters is unknown of origin and unsupported by the science.

        • Sam NC
          Posted Jun 27, 2010 at 6:20 PM | Permalink

          1.5m was based on TTY’s 12% water volume to give rise of 7m after the Polar ice caps all melted, i.e. 12/2.5*7.

  6. Laurent Cavin
    Posted Jun 25, 2010 at 4:20 PM | Permalink

    Unrelated (sorry to post it in this thread….)

    Swiss Re (Reinsurance company) published a refutation of skeptics arguments. If anybody’s interested, see http://media.swissre.com/documents/rethinking_factsheet_climate_sceptic.pdf

    It contains for instance a short discussion of Mann’s Hockey Stick and makes short work of Steve’s work:

    [quote]The alternative results presented by MM as well as by Soon/Balliunas were shown to be biased by omitting relevant data and application.[...] the results of MM show a warm period in the 14/15th century, ie during the beginning of the Little Ice Age. This is in contrast to all other independent reconstructions.[/quote]

    Regards,

    Laurent

    • BillyBob
      Posted Jun 25, 2010 at 5:30 PM | Permalink

      Doesn’t Mann’s Hockey Stick show 1350 – 1425 as the 2nd/3rd warmest pre-1900 period?

      Isn’t that the 14th and 15th centuries?

    • David S
      Posted Jun 25, 2010 at 5:55 PM | Permalink

      Steve
      You might want to think about demanding a retraction. The Chief Executive is Stefan Lippe and the Chairman is Walter Kielholz. Oddly enough, the marketing director is called Lies.

    • Tom Gray
      Posted Jun 25, 2010 at 9:44 PM | Permalink

      It appears that these people have no understanding of Steve mcIntyre’s work.

    • Geoff Sherrington
      Posted Jun 25, 2010 at 11:46 PM | Permalink

      Laurent Calvin. Swiss Re fail at Figure 1. The reference term of years 1961-1990 is below zero for all graphs given, when it should average to zero by convention. What is more, data from various sources should give the same average (zero) over the reference period. They do not.

      Why read further when the first test fails? Elapsed test time to first error, 3 minutes.

      • Laurent Cavin
        Posted Jun 26, 2010 at 7:42 AM | Permalink

        Well, I did not say anything about them being right or wrong. I just wanted to share the link with all of you, and especially Steve as his work is criticized..

        One thing I must say however – even if I am not convinced by their document – is that Swiss Re puts its money where its mouth is.

        Let me explain: one could pretend scientists have an advantage of supporting the “consensus” in order to get another grant or a better position. But the Insurance company is basing its policy, i.e. its forecasts and its calculations of premium, on the reality of Global Warming. They have no specific interests for that, and one could argue that they could loose money if they bet wrong. For me that a slightly more “neutral” opinion, and if they are convinced enough to publish a (definitively not neutral) refutation of skepticism, that’s a strong statement.

        My 2 cents…

        • BillyBob
          Posted Jun 26, 2010 at 11:35 AM | Permalink

          “They have no specific interests for that”

          Using one example, the AGW side claims it will increase the number of hurricanes. It that was so, claims for huricanes will rise. And therefore insurance companies wil raise rates and/or offset some of their potential claims by buying reinsurance from a reinsurance company.

          If fearmongering leads to more business but no more claims, then its a big financial win for a reinsurance company.

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

    • Hu McCulloch
      Posted Jun 26, 2010 at 8:33 AM | Permalink

      Laurent — The Swiss Re compilation looks interesting, but is way off topic on this thread. The recent “Unthreaded” thread at http://climateaudit.org/2010/06/15/unthreaded-39/ would be the appropriate place to ask Steve (and readers) for his response to the Hockey Stick section A3. He’s been over these points repeatedly on CA, but might want to organize a refresher post around the Swiss Re discussion.

    • Laurent Cavin
      Posted Jun 26, 2010 at 11:02 AM | Permalink

      Off-topic discussion.

      Please continue on the last unthreaded.

      Moderators: feel free to erase the whole discussion here!

  7. Sam NC
    Posted Jun 25, 2010 at 4:27 PM | Permalink

    @Luboš Motl,

    How did you get 7m sea water level rise? Is it from Al Gore?

    • tty
      Posted Jun 25, 2010 at 5:20 PM | Permalink

      7 meters is about right for the sealevel rise that would be caused by an (impossible) complete melting of the Greenland ice. The volume of the ice is known with reasonable precision, and it is easy to calculate the volume change (about -12%) when glacier ice turns into seawater.

      • Sam NC
        Posted Jun 25, 2010 at 8:44 PM | Permalink

        See this link:

        http://hypertextbook.com/facts/2000/HannaBerenblit.shtml

        Polar ice caps melt together is less than 0.25% by water volume on Earth if you look at the bottom of the page. Prove that page is wrong if you can!

        • tty
          Posted Jun 26, 2010 at 4:06 AM | Permalink

          The figures in your reference are correct, but have no bearing on the matter being discussed. A rise of sea-level by say, 7 meters is minimal compared to the average depth of the oceans, and involves a very small percentage of all the water on Earth.

        • Sam NC
          Posted Jun 26, 2010 at 4:24 AM | Permalink

          I disagree with your conclusion. If all ice on the Earth melts, it will only contributed to about 1.5m sea water level rise, not 7m. If you sceptics are with the same attitudes (wishy washy) on numbers as those AGW alarmists, I will be equally disappointed.

      • Sam NC
        Posted Jun 25, 2010 at 9:05 PM | Permalink

        OK, Icecaps volume is 2.5% water volume rather than 12.5% or 0.25%.

    • Robert
      Posted Jun 25, 2010 at 10:33 PM | Permalink

      The number is not from al gore and you should consider fact checking before throwing accusations out there. 6 meters might be more appropriate at this time but it is difficult to assess because of the topographic elements. All that being said the complete melting of greenland is NOT an impossible thing. During the past interglacial it has been argued that Greenland lost almost all of its mass and recent papers. Stone et al. (2010) show that at CO2 levels between 400 and 540 ppm Greenland has melted completely in the past and that this could(and I said could) be something which we see potential for in the future. Due note that in 2002 estimates would of said that it would take 22,000 years for greenland to melt and in 2009 estimates were around 10 000 years (286 GT per year loss). At the rate of current acceleration (30 GT per year) (which is believed to be unsustainable and should slow) then the greenland ice sheet would be gone within the next 100 years. Once again, unlikely but don’t say never. Significant losses are in fact occurring and it would be foolish to ignore the extensive literature on the subject.

      • tty
        Posted Jun 26, 2010 at 3:59 AM | Permalink

        The idea that Greenland lost nearly all of its icecap during the last interglacial is nonsense, and part of AGW mythology. ALL ice cores that have been drilled along the ice-divide have found Eemian ice at the bootom (including Dye 3 on the southern ice dome), as did even the core through the small isolated Renland icecap (in this case admittedly only late Eemian ice, so Renland may have been ice-free during the warmest early part of the Eemian). Temperatures on Greenland at the time was about 5 degrees centigrade warmer than now (measured inter alii on the supposedly non-existant Eemiann ice). As for the time it would take for the Greenland ice cap to melt, it is interesting to note that after the end of the last glaciation it took the Scandinavian ice cap about 2000 years to melt. Climate at the time was warmer than it is in Scandinavia today, and for most of the time the ice could calve into the Baltic, which is a much faster process than melting. Topography was also much more favorable for melting through basal sliding since the ice was retreating up-slope, not down-slope as would be the case in Greenland.
        As for the impossibility of Greenland becoming completely ice-free this is because Eastern Greenland is a large hichland with peaks ofer 3000 meters and large plateaus over 2000 meters. How warm would it need to get to melt glaciers at 3000 meters, north of the arctic circle? And indeed IRD in seabottom deposits show that there has been montane glacikation (with tidewater glaciers) in Greenland at least since the late Oligocene. As for when lowland glaciation started in Greenland, this is not known (and the CO2 level at the time therefore indeterminate). It is thought that the last time large lowland areas in northern Greenland was ice-free was about 2.5 millon years ago, when the Kab Köbenhavn formation was deposited.

        • robert
          Posted Jun 28, 2010 at 7:17 AM | Permalink

          I’m not arguing that we will see a complete disintegration of the Greenland ice sheet similar to in the past, but smith et al. 2010 (located online at the cryosphere) makes such an argument with a very long paper that seems well written. Secondly, your argument assumes that there needs to be a massive warming to eliminate high altitude glaciers. Remember, glaciers are mostly dependent on Summer temperatures and then lesser so on wintertime precipitation. Any change in either of these factors can change the viability for glaciers even in high altitudes because they can melt away quickly once out of equilibrium. Certainly topographic constraints will preserve some glaciers (such as remnant ones in the torngat mountains of northern Labrador which are far below the regional glaciation line and at relatively low altitudes compared to in other regions) but the point is that large expanses of the main ice sheet does have the potential to be lost and once system inertia pushes the sheet in one direction it takes a large sustained negative forcing to bring the system back into equilibrium.

          6 meters is just a theory which I believe has validity because although Greenland has been estimated at 7.2 sea level rise (Bamber et al. 2001) I think that it will likely prove to be similar to the west antarctic ice sheet which has regional and topographic elements which will keep sea level rise below 4 meters despite 5-6 meters being available.

        • Bill Stoltzfus
          Posted Jun 28, 2010 at 7:53 AM | Permalink

          tty:

          Your comment about the Eemian ice got me wondering–say there was a glacier that was X meters thick, and then a warm period that melted some of the glacier (including some from the top), then a cold period that added a bunch more back on. Now, today they do an ice core and go all the way to the bottom. Is there a layer at that boundary between old ice and new ice that shows there was a discontinuation? If not, how do they account for the time lapse in the middle?

          Thanks,
          Bill

        • Pat Cassen
          Posted Jun 28, 2010 at 9:24 AM | Permalink

          Bill – See
          hhttp://www.nature.com/nature/journal/v343/n6259/abs/343630a0.html

      • Sam NC
        Posted Jun 27, 2010 at 5:25 AM | Permalink

        “The number is not from al gore and you should consider fact checking before throwing accusations out there. 6 meters might be more appropriate at this time but it is difficult to assess because of the topographic elements.”

        So how certain is the water volume in the last table of

        http://hypertextbook.com/facts/2000/HannaBerenblit.shtml

        Can you show me your calculation of the 6m and assumptions?

  8. Pete K
    Posted Jun 25, 2010 at 6:30 PM | Permalink

    I am new to your blog and was steered here by Mr. Montfords book. Also please excuse me as I am not a scientist. For a few years now and more so since “the Hockey stick Illusion” I would like to ask how the Ice core proxies are reconciled with known depths in Greenland? A a member of the P38 lightening Association there is very good data when a P38 aircraft that crashed at the eastern coast of Greenland in 1942 then pulled out of the ice almost 50 years to the day by melting a hole down to it. The P-38 was found at 268 feet deep in the ice. Are the core collectors going that deep? They better be because the 268 feet reflects 50 years not including some drift from the original location. Do the core scientists also reconcile snow drifts as well? Something is really wrong here.

    • Pete K
      Posted Jun 25, 2010 at 6:37 PM | Permalink

      Sorry forgot, here is the web site for further information on “Glacier girl” the P-38 recovered from the Greenland ice if you are interested: http://p38assn.org/glacier-girl.htm

      It would be nice to see Glacier Girl a poster girl for uncovering flawed data if that is the case.

      • E O'Connor
        Posted Jun 26, 2010 at 4:26 AM | Permalink

        Whoa Pete K, steady the horses there!

        Until someone posts a definitive reply try this link about ice cores from Greenland, Antarctica and non-polar areas.

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

        “The North Greenland Eemian Ice Drilling (NEEM) site is located at 77°27’N 51°3.6’W, masl. Drilling started in June 2009 and expects to hit bedrock in 2010. The ice at NEEM may be 2545 m thick. As of Sep 1, 2009, the coring has reached a 1757.84 m depth for this season.”

        I had a close relative who flew P47s so I found the history of that P38 fascinating.

        For CA readers, my link shows a picture taken by Lonnie of an ice core sample taken from a drill.

        • tty
          Posted Jun 26, 2010 at 2:27 PM | Permalink

          There is a good popular account of the history of ice coring on Greenland and its scientific results in the book “Frozen Annals” by Willi Dansgaard. It is available online here:

          http://www.iceandclimate.nbi.ku.dk/publications/FrozenAnnals.pdf/

          Well worth reading for anyone interested in climate history.

        • Pete K
          Posted Jun 26, 2010 at 3:12 PM | Permalink

          Wow Mr. O’Connor;”steady the horses there”? Thats one impolite way to diminish my thoughts by indicating I am in a rush to judgement. Too bad it wasn’t made in person as I always have a great reply to those elitist remarks. First of all I would never get my information from Wikipedia as I am not a fan of Ad Hoc information. As for the coordinates of the drilling you mention, is it near where the P-38 was found? And finally is that site near a coastline? They can take as many core samples from the ice as they have from the trees. The maybe non-scientific question I have is: If the ice is melting how does an airplane wind up over 25 stories deep in the ice and drift over a mile in only 50 years? The ice Core research I have seen (Not all of it of course)does not reconcile that matter.

        • E O'Connor
          Posted Jun 27, 2010 at 12:29 AM | Permalink

          Pete K, you said in your original post –

          “The P-38 was found at 268 feet deep in the ice. Are the core collectors going that deep? They better be because the 268 feet reflects 50 years not including some drift from the original location. Do the core scientists also reconcile snow drifts as well? Something is really wrong here.”

          The reference to the NEEM data was that ice cores are drilled considerably deeper than 268 feet.

          Given the information you provided and the questions you asked, my ‘steady the horses’ comment was about rushing to the judgement “Something is really wrong here”.

    • Posted Jun 25, 2010 at 10:50 PM | Permalink

      Re: Pete K (Jun 25 18:37),
      Re: Pete K (Jun 25 18:30),

      A good place to start is “The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future” Amazon . They’ve gone to bedrock, about 10,000 ft. at the center of the ice dome. But the core becomes uninterpretable near bedrock, due to lateral flow & thinning of the ice. Interesting book, minimum of propaganda, a bit simplistic.

      Yes, there is evidence for very rapid climate shifts — in Greenland. It’s not at all clear what this means for the temperate part of the world. And we already knew that the inhabitability of Greenland is …. variable.

      Happy reading–
      Pete Tillman

      • Pete K
        Posted Jun 26, 2010 at 2:52 PM | Permalink

        Interesting you said the core becomes uninterpretable near bedrock, due to lateral flow. Not only the P-38 but others in the squadron were reported by the recovery crew as having drifted over a mile. Would this then make ice cores over the last 50 years uninterpretable? And again what about the drifts altering the depth.

  9. Mescalero
    Posted Jun 25, 2010 at 10:02 PM | Permalink

    I heard about this well over a month ago at a AIAA presentation in Pasadena, CA. The person making the presentation is a well-known and respected geologist at JPL. Interesting stuff to say the least

  10. Justmeint
    Posted Jun 26, 2010 at 12:09 AM | Permalink

    I am not good at maths….. but I can see there is still a strong argument for and against climate change (AGW)…

    Have any of you considered the damage and possible devastation that maybe caused by the gushing methane in the Gulf of Mexico?

    Methane being released in the Gulf of Mexico could precipitate Global Warming – very very fast:

    In an article on Methane Hydrate Ice you find that: Recent discoveries about the existence of a vast band of Methane Hydrate Ice along the world’s continental Slopes, at approx. 500 meters depth, have revolutionized the theories of the Ice Age and Global Warming Cycles. The accumulation of Methane Ice leads to Ice Ages and the rapid melting and effervescence of this ice and gas leads to an equally rapid Global Warming.

    http://just-me-in-t.blogspot.com/

    Vast amounts of methane, a greenhouse gas 23-25 times more potent than carbon dioxide, are locked in the deep sea and in the frozen soils of Siberia, Northern Europe, and North America, but warming could trigger rapid thawing that would release billions of tons into the atmosphere.

    “The potential consequences of large amounts of methane entering the atmosphere, from thawing permafrost or destabilized ocean hydrates, would lead to abrupt changes in the climate that would likely be irreversible. We must not cross that threshold.

    • tty
      Posted Jun 26, 2010 at 4:02 AM | Permalink

      The amount of methane being released is minuscule in a global context.

  11. weibel
    Posted Jun 26, 2010 at 1:56 PM | Permalink

    Klimazwiebel, no Klimazweibel

  12. David Weisman
    Posted Jun 26, 2010 at 5:32 PM | Permalink

    Yet I seem to recall that during ice ages the sea level was much lower, and that when it was warmer than today, like in the Jurassic, the sea level rose much higher. You could argue this increase comes from the increased volume of the warmer oceans instead of melting ice caps, but I think this would require more expansion then we currently expect.

  13. Sam NC
    Posted Jun 27, 2010 at 7:27 AM | Permalink

    @ Luboš Motl, tty, Robert,

    Can you show me your calculations and assumptions to arrive at the respective sea water level rises when all ice on Earth melt?

    @ Anyone

    Please show me your calculations and assumptions if you have done any, thanks.

    • Johan C
      Posted Jun 27, 2010 at 4:38 PM | Permalink

      Lubos Motl’s calculations and Mathematica source code (bottom) are available here http://motls.blogspot.com/2010/06/if-greenland-melted-sea-level-in.html

      • Sam NC
        Posted Jun 27, 2010 at 6:14 PM | Permalink

        I read that link b4 I posted my question. His calculation was based on assumption of 7m sea water rise, then correct the assumption at different locations. My question is how did he get the 7m assumption.

        • robert
          Posted Jun 28, 2010 at 2:53 PM | Permalink

          Read Bamber et al. 2001 for example. The assumptions are made based upon measurements of ice thickness across greenland and then subsequent measurements of bed topography. It is difficult to get an absolute value but 7 meters has been claimed by the numerous estimates that have so far been done.

  14. Posted Jun 27, 2010 at 8:15 AM | Permalink

    real evidence for lower sea levels during last ice age. Doggerland was inhabited and archeological artefacts have been caught in fishing nets:

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

    During the most recent glaciation, the Devensian glaciation which occurred around 10,000 years ago, the North Sea and almost all of the British Isles were covered with glacial ice and the sea level was about 120 metres (390 ft) lower than it is today. Much of the North Sea and English Channel was an expanse of low-lying tundra, extending around 12,000BC as far as the modern northern point of Scotland.[4]
    Evidence including the contours of the present seabed shows that after the first main Ice Age the watershed between North Sea drainage and English Channel drainage extended east from East Anglia then southeast to the Hook of Holland, not across the Strait of Dover, and that the Thames, Meuse, Scheldt and Rhine rivers joined and flowed along the English Channel dry bed as a wide slow river which at times flowed far before reaching the Atlantic Ocean.[4][3] At about 8,000BC, the north-facing coastal area, now called Doggerland, had a coastline of lagoons, marshes, mudflats, and beaches. It may have been the richest hunting, fowling and fishing ground in Europe available to the Mesolithic culture of the time

  15. oneuniverse
    Posted Jun 27, 2010 at 11:44 AM | Permalink

    Also by Zorita, concerning climate models :
    Zorita & González‐Rouco 2000, “Disagreement between predictions of the future behavior of the Arctic oscillation as simulated in two different climate models: Implications for global warming”

  16. robert
    Posted Jun 28, 2010 at 2:51 PM | Permalink

    The Working Group 1 documents of the IPCC 2007 AR4 does not make any sort of commentary such that himilayan glaciers will disappear in 30 years. It was a mistake made by WG2 not WG1 who would be responsible for the science on the greenland ice sheet. The greenland ice sheet has been extensively studied unlike himilayan glaciers. It will not disappear within 100 years but is losing mass extensively. If you do not believe that argument then there is a plethora of mass balance papers you can read and evaluate.

  17. Sam NC
    Posted Jun 28, 2010 at 6:50 PM | Permalink

    @ Luboš Motl,

    Do you think you can calculate sea water level rise (all ice on the Earth melt) based on data from this link:

    http://hypertextbook.com/facts/2000/HannaBerenblit.shtml

    Regards,

    • Sam NC
      Posted Jun 29, 2010 at 8:02 AM | Permalink

      I think I have waisted my time here. Disappointed that you are no better than Al Gore.

      • David
        Posted Jul 1, 2010 at 10:40 AM | Permalink

        Sam, why don’t you ask Luboš Motl on his blog which is where he would likely want to carry on an conversation about his calculations.

  18. Posted Jun 29, 2010 at 6:05 PM | Permalink

    Amazing how slowly science percolates
    Bert Vermeersen reported this phenomenon already in 2007

    http://www.kennislink.nl/publicaties/antarctica-is-veel-gevaarlijker-dan-groenland

  19. san quintin
    Posted Jun 30, 2010 at 11:42 AM | Permalink

    Hi Hans
    Yes, this phenomenon has been known by Quaternary scientists for a long time and forebulges can be seen on present day glacial environments.

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