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Earth Science

Newly Discovered Meltwater Streams Flow Beneath the Antarctic Ice Sheet 130

Posted by timothy
from the streams-of-whiskey-they-are-flowing dept.
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.

    • by DavidClarkeHR (2769805) <david@clarke.hrgeneralist@ca> on Sunday October 06, 2013 @11:18PM (#45055531)

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

      It's new knowledge, even if it isn't a new phenomenon (which it might be - who knows?). Kinda like ... math. Relativity (as it is). Microbes.

      Even if it isn't a new development, or a new phenomenon (we don't know), we do need a baseline measurement.

      • by fyngyrz (762201) on Sunday October 06, 2013 @11:42PM (#45055667) Homepage Journal

        we do need a baseline measurement.

        Certainly. Then, and only then, will measurement of volume and rate acquire meaning. In the interim, statements like:

        Even if it isn't a new development,

        ...and...

        could be destabilising parts of the Antarctic ice shelf immediately around them and speeding up melting

        ...are no more than alarmist bullshit.

        Now, next year (and years), when they measure those streams, if the aggregate volume is up, I'll nod in agreement when someone says "this could be a result of warming." Even more meaningful, if the trend continues upwards, we have an actual indicator. But right now we have the equivalent of "hey, here's a traffic signal" with absolutely no indication of if it's red, green, or broken.

        • by rve (4436) on Monday October 07, 2013 @01:51AM (#45056161)

          Why does any mention of ice or antarctica have to turn into an ideological battle over the climate?

          This melt water is forming at the bottom, beneat an ice sheet that's more than two and a half miles thick in places. It's completely shielded from the climate, which acts on the surface and on the ocean.

          There are places in northern Europe, siberia, alaska, canada, where a few hundred feet below the surface you still find permafrost left over from the last ice age. It's so far from the surface that it apparently takes more than 10,000 years to melt.

          • 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 rve (4436)

              That ice age permafrost is in danger [bbc.co.uk] of pronounced melting too.

              I think you're confusing (near) surface permafrost in the arctic, due to the average annual temperature being below freezing, and ice age permafrost 300 ft below the surface that's there because the average conditions there over the Quaternary period has been 'covered with an ice sheet' - even if that hasn't been the case in 10,000 years. In most places, I imagine (no data available that I'm aware of), what's buried that deep will probably stay there whether it's frozen or not.

    • by Anonymous Coward

      And I'm sure the scientists never once thought of that possibility or looked at this before. They should be looking to random slashdot posters for their information instead!

    • by Joce640k (829181)

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

      Right, but now we can see them and know if they're growing or not.

      It's one more item to track on the ever-growing list of proofs.

  • The (actual) Surf (Score:5, Interesting)

    by MrKaos (858439) on Monday October 07, 2013 @01:01AM (#45056007) Journal

    I know, the correlation/causation comment will come up, but you would never know the water temperature unless you got in the water and feel it for yourself over 2-3 decades of actually being in the water and knowing when to get in. I wouldn't call 250metres a stream, but other noticable thing is the way the weather has changed from a smooth transition to summer where it gradually got hotter to bursts of weather change where you will suddenly get days of really warm weather in winter and then back to cold and visa versa in summer.

    I regularly goes for a swim or a surf on the east coast of Australia and for the last decade years the water has been really cold during seasons where I used to notice it was pretty warm. It has altered my whole habit of surfing. I used to go into the water around September and now it's late October. I love the waves but the goolie shock is just to severe. My mates would say the same thing and often the comment 'at least we know where the ice caps are melting to' would come up.

    • Re:The (actual) Surf (Score:4, Interesting)

      by MrKaos (858439) on Monday October 07, 2013 @01:11AM (#45056051) Journal
      I also wanted to mention that it would be cool to get some little robots into these streams and map them under the ice to find out where they start and finish.
    • by zmooc (33175) <zmooc&zmooc,net> on Monday October 07, 2013 @01:57AM (#45056183) Homepage

      I cannot find any data on the Pacific ocean near Australia, but in many places oceans are getting slightly cooler. This has nothing to do with melt water, though; there's much too little of that to have a measurable influence, especially at your latitude. Instead, it is most probably due to changing currents.

      However, a very likely alternative cause for you guys feeling colder would be that you're getting older; as people get older, they feel colder quicker.

      • Re:The (actual) Surf (Score:4, Interesting)

        by MrKaos (858439) on Monday October 07, 2013 @07:45AM (#45057241) Journal

        However, a very likely alternative cause for you guys feeling colder would be that you're getting older; as people get older, they feel colder quicker.

        Oh no doubt about that, I have to leave my walking stick at the beach so I can find my towel!!!

        I cannot find any data on the Pacific ocean near Australia, but in many places oceans are getting slightly cooler. This has nothing to do with melt water, though; there's much too little of that to have a measurable influence, especially at your latitude. Instead, it is most probably due to changing currents.

        I'm generally lean but have a bit of fat after winter so the icey water just strips it from you (apart from having a wettie on - which slows me down) so it seems to balance out and I want to catch as many waves as I can.

        The thing is I have to swim really hard to get the waves so I'm working a lot to get them. The waves I'm after are about the same as the ones for a board as I am a pretty big guy and I get moving pretty fast. Catching them close to shore is dangerous as the waves tend to dump you on sand and I have been badly concussed from that before. Because of that I generally swim a good 100-300 meters from shore where the waves are bigger from sand banks - which you can see underwater.

        When I'm out there I can feel the difference between the first metre and, when diving down, the next four or five (I'm a shark chicken - I don't want to be lunch so I keep an eye out). The water temperature is generally more stable the deeper you go but what gets me is that it is more often consistently cold all the way to the surface than not. You can feel the difference in certain patches of water as the temperature changes when you swim through them. This is the biggest change that I note (apart from seeing less penguins, seals and turtles).

        Current change seems like a good point however I would then expect it to cycle between behaviours. So it could be because I'm an old bastard however there is a distinct change in the patterns of water temperature that entails the frequency and duration of warm patches of water. Whatever is happening, something is going on.

  • Altmetrics is a new-ish bibliometic service for scholarly journal articles, including Nature, which is where this was published. Altmetrics includes mainstream media coverage as as well as social media appearance counts e.g. SciBlogs, Twitter as valid data. Physorg is mentioned but I do not see Slashdot [nature.com]. We, the Slashdot collective, demand recognition!

    * Unless we are deemed insufficiently social? Anti-social? Of course not.
    ** Altmetrics is beta-ish, possibly open source, so my indignation is mostly insincer

  • Why it matters (Score:3, Insightful)

    by quantaman (517394) on Monday October 07, 2013 @04:47AM (#45056703)

    Antarctica is one of the major feedbacks [gwynnedyer.com]:

    The protective covering of floating ice that has shielded the Arctic Ocean from solar heating for so long is now going fast, and we will probably see an ice-free Arctic Ocean in the August-September period as early as the 2020s. Mercifully, this is the smallest of the three major feedbacks in terms of its impact – but it triggers a bigger one.

    The warmer air and water in the Arctic then starts to melt the permanently frozen ground and coastal seabed (permafrost) that extends over more than ten million square km. (3 million sq. mi.) of territory, a considerably larger area than Australia. This melting releases a huge amount of methane that has been locked into the ground for millions of years. Methane is a far more effective warming agent than carbon dioxide, and so we spin closer to runaway.

    [...]

    Those are the killer feedbacks. Earth has lurched suddenly into a climate 5-6 degrees C higher than now a number of times in the past. The original warming usually came from massive, long-lasting volcanic eruptions that put a large amount of CO2 into the atmosphere – but in every case it was feedbacks like these that carried the planet up into a temperature regime where there was a massive dieback of animals and plants.

    Considering we're already experiencing major extinctions I'm not sure I want to stack ecological disasters.

  • Only two people in this entire comment section have successfully dodged the global warming spin hucksters to note the following:

    The mean annual surface air temperature of the Antarctic interior is -57C. Surface melt refreezes rather promptly. But ice is great insulation, and geothermal energy comes up from the Earth to melt the bottom of the ice sheet. This meltwater flows in streams and rivers across the world's largest continent until it becomes the world's largest rivers, inevitably finding the sea. This should be obvious.

    This has nothing to do with industrial exhaust.

    So chill out. (In fact, you don't have any other choice. We're entering another ice age. Wise up. Be prepared for a really shitty snow-heavy winter.)

  • "The streams of water, some of which are 250m in height and stretch for hundreds of kilometres"

    WTF?

    Since when did we start measuring rivers' height?

    • by iggymanz (596061)

      these are above ground level; the ice cap is nearly three miles thick (4700 meters) in places!

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