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Earth Science

Newly Discovered Meltwater Streams Flow Beneath the Antarctic Ice Sheet 130

The Telegraph reports that previously undetected streams of meltwater have been observed beneath the Antarctic ice sheet. "The streams of water, some of which are 250m in height and stretch for hundreds of kilometres, could be destabilising parts of the Antarctic ice shelf immediately around them and speeding up melting, researchers said. However, they added that it remains unclear how the localised effects of the channels will impact on the future of the floating ice sheet as a whole. The British researchers used satellite images and radar data to measure variations in the height of the Filchner-Ronne Ice Shelf in West Antarctica, which reveal how thick the ice is." The paper itself is paywalled, but the abstract is available online.
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Newly Discovered Meltwater Streams Flow Beneath the Antarctic Ice Sheet

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  • by tftp ( 111690 ) on Sunday October 06, 2013 @11:12PM (#45055507) Homepage

    "newly discovered" != "new". Those streams may have been there for millions of years. They certainly were there when the continent was free of ice.

  • Re:Ummmm (Score:5, Informative)

    by Gadget_Guy ( 627405 ) on Monday October 07, 2013 @01:37AM (#45056113)

    It's common knowledge that, unlike the arctic, Antarctic ice has been increasing.

    As is often the case this common knowledge is actually a common misconception. While the sea ice is increasing, the land ice is shedding mass at an accelerating rate [skepticalscience.com]. Since the sea ice is already in the sea, it does not affect sea levels at all. Thawing land ice does increase sea levels, since it introduces water to the sea that used to sit on land.

  • by jovius ( 974690 ) on Monday October 07, 2013 @04:25AM (#45056651)

    In a way it's connected with the climate change. The cold meltwater streams allow warmer seawater under the ice sheet when they meet the sea. Because the seas are warming up the calving underneath is pronounced.

    Greenland has similar kind of meltwater streams, and at least some of them actually begin on the surface of the ice. Extreme Ice Survey [extremeicesurvey.org] has great material. That ice age permafrost is in danger [bbc.co.uk] of pronounced melting too.

  • by Anonymous Coward on Monday October 07, 2013 @06:35AM (#45056959)

    the world's largest continent

    Antarctica is the fifth-largest continent.

  • by ElBeano ( 570883 ) on Monday October 07, 2013 @06:46AM (#45056983)
    The extent of sea ice during the winter seems to be growing, but the total MASS of ice, sea and land, continues to shrink. You're the propagandist.
  • by KeensMustard ( 655606 ) on Monday October 07, 2013 @08:15AM (#45057367)
    Joanne Nova played a mean trick on you!

    You'll note that the phrase "Antarctica gaining Ice Mass (balance*) — and is not extraordinary compared to 800 years of data" implies an increase in overall volume of ice which is the take away - you are supposed to assume she is talking about volume. But she isn't:

    DumbScientist below helpfully points out that Zwally is using Total Mass Balance, which is different to Surface Mass Balance. The SMB figure involves "precipitation, evaporation and snowdrift physics" but not glacier run-off. Thanks to both readers.

    Neatly tucked away there is the truth, the article in question is not referring to glacial ice volumes but to snow build up due to increased precipitation, and ignores the overall loss of volume due to glacial run off. But you can see how she has structured that, so carefully, to suggest something completely different in the headline but at the detail level, to admit that the paper in question has nothing to do with ice volume ("total mass").

    What a spectacular lie! Almost as good as the lie she told a few weeks ago, you remember the one, about how she had seen a draft of the IPCC report containing a halving of CO2 sensitivity and then later she said they must have taken it out in the final version? There was no such draft, and she never saw a draft, why would she? She lied.

    Please don't use the hilariously named "skeptical science" as your source.

    We can, and will, use whatever source we choose. It's up to you to prove that Skeptical Science is factually incorrect. Start with Tyndall, then Arrhenius and work forward.

  • by tbannist ( 230135 ) on Monday October 07, 2013 @09:55AM (#45058107)

    What a load of utter tripe. Antarctic ice sheet gains exceed losses

    That was a workshop based on preliminary results, here's the final research paper [sciencemag.org] from the same scientist:

    We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year1 to the rate of global sea-level rise.

    Note the total is -213 ± 142.

    Listen, here's the deal: You lost. Your narrative of catastrophic climate change due to man emitting Co2 into the atmosphere is a busted flush.

    I wish it were that easy.

  • by NeutronCowboy ( 896098 ) on Monday October 07, 2013 @12:40PM (#45060301)

    15 years of no warming despite CO2 emissions continuing

    Convenient use of a record high as your starting point. Care to redo your calculations with any other window? Maybe, say, a 20 year window? Or even a 10 year window? What about a 12 year window?

    greatly increased Arctic Ice coverage,

    [Citation needed] and [Confusing a rebound from a historic low to slightly less historic lows with an increase over average].

    increasing Antarctic ice thickness

    [Confusing weather with climate] and [Lack of understanding of ice formation]

    increasing Antarctic sea ice coverage

    [Cherry-picking specific regional ice data points] and [Mistaking surface for volume].

    no observed retreat in Himalayan glaciers

    [More reading needed]. See also http://www.nature.com/ngeo/journal/v4/n3/abs/ngeo1068.html [nature.com]

    I'm just the guy who has been making physical chemistry arguments that show that CO2 has no net effect on the heat capacity of the atmosphere for the last few years

    ... which has nothing to do with the problem of CO2 trapping IR, or with why the atmosphere is heating up.

    arguing instead that what warming we saw was from increased water vapor emissions, which maintain a tight equilibria with their rate of emissions

    Water vapor cannot drive long-term heating. A single cold-spell will remove water vapor from the air, which will reduce temperatures, which will remove more water from the air.... Water vapor is the result of warming, not a forcing.

    thus the lost decade global growth lead to a lost decade of warming

    The global economy was working in overdrive until 2000-2001, and again from 2005 to 2008. Your own data calls you a liar.

    bringing AGW idiots to take because they are ignoring the real threat from CO2--ocean acidification and the collapse of already overstressed fisheries.

    I'm glad you'll find that all kinds of scientists, but especially marine biologists and oceanographers would love your help in spreading message. Care to sign up maybe with an organization like NOAA or the Monterey Bay Aquarium Research Institute?

    But hey, let's all ignore physics

    Says the guy who mistakes anecdotes for data, cherry-picks his time frames, misunderstands the overall and problem and thinks that he has a better understanding of physics than Physicists.

    Tell you what, write a paper about your insights, and if you're right, the Nobel prize in a few areas is yours. How is that for an incentive to go show up all the AGW believers? You'll be right up there with Galileo, Kopernicus, Pasteur, and a few other up-enders of the consensus.

"What man has done, man can aspire to do." -- Jerry Pournelle, about space flight

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