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Earth Science

Large Ice Shelf Expected To Break From Antarctica 278

Posted by Soulskill
from the too-cool-for-school dept.
MollyB sends this excerpt from CNN: "A large ice shelf is 'imminently' close to breaking away from part of the Antarctic Peninsula, scientists said Friday. Satellite images released by the European Space Agency on Friday show new cracks in the Wilkins Ice Shelf where it connects to Charcot Island, a piece of land considered part of the peninsula. The cracks are quickly expanding, the ESA said. ... The Wilkins Ice Shelf — a large mass of floating ice — would still be connected to Latady Island, which is also part of the peninsula, and Alexander Island, which is not, said professor David Vaughan, a glaciologist at the British Antarctic Survey. ... If the ice shelf breaks away from the peninsula, it will not cause a rise in sea level because it is already floating, scientists say. Some plants and animals may have to adapt to the collapse."
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Large Ice Shelf Expected To Break From Antarctica

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  • If the ice melts (Score:2, Insightful)

    by snsh (968808)
    Will the ocean level rise, fall, or remain the same?

    I'm betting it will rise a little bit because the salt concentration is different in the ice than in the ocean.
    • by Psychotria (953670) on Saturday April 04, 2009 @02:19AM (#27455379)

      Yeah, and once it melts its salt concentration will change!... or not.

    • Re:If the ice melts (Score:4, Informative)

      by TapeCutter (624760) * on Saturday April 04, 2009 @02:40AM (#27455481) Journal
      I think the salt will just mean the fresh melt forms a layer on top, you can test it youself with a glass of salty water and some ice cubes. However we have known for a while now that overall Antarticia is losing mass [nasa.gov] and that sea levels are already rising.

      Quote from TFL: "The estimated mass loss was enough to raise global sea level about 1.2 millimeters (0.05 inches) during the survey period; about 13 percent of the overall observed sea level rise for the same period. The researchers found Antarctica's ice sheet decreased by 152 (plus or minus 80) cubic kilometers of ice annually between April 2002 and August 2005."

      Greenland is also losing mass. [nasa.gov]
      • Re:If the ice melts (Score:5, Interesting)

        by Rockoon (1252108) on Saturday April 04, 2009 @03:25AM (#27455691)

        The researchers found Antarctica's ice sheet decreased by 152 (plus or minus 80) cubic kilometers of...

        An error margin greater than 50%? Presuming that this is based on a typical 3 standard deviations...

        ...the chebyshev limit says there is still a whopping 11% chance that the actual value is outside the range...

        I don't see any statistics experts mentioned in that link, so I gotta assume that we cannot expect a normally distributed error, that in fact they have no idea what the distribution might be.

        • Re: (Score:3, Insightful)

          by TapeCutter (624760) *
          ...the chebyshev limit says there is still a whopping 11% chance that the actual value is outside the range... I don't see any statistics experts mentioned in that link, so I gotta assume that we cannot expect a normally distributed error, that in fact they have no idea what the distribution might be.

          There are some 50 published papers from the journals Nature [google.com.au] and Science [google.com.au] alone, when your finished teaching them stats maybe you can teach them risk management.
          • Re: (Score:3, Funny)

            by Rockoon (1252108)
            One of the problems is that the peer reviewer is supposed to be an expert in the papers field (ex: climate science), rather than the methodology used (ex: statistics)

            A popular example is Mann's flawed implementation of Principle Component Analysis, peer reviewed and then published by one of the very same journals that you are trying to use for your arguement-from-authority fallacy.

            Lets examine what Mann was doing:

            AlgorihmDescription.txt [nature.com]

            Thats from one of the journals you cited, so you trust that it
            • Re:If the ice melts (Score:5, Informative)

              by TapeCutter (624760) * on Saturday April 04, 2009 @06:57AM (#27456419) Journal
              Dude, stop dragging those red-herrings around, they stink.

              If by pointing to Mann's reconstruction methods you mean to imply Mann, et al's hockey stick [realclimate.org] was debunked you are simply wrong...

              The statisticians at the National Academies do not agree with you, or should I say their written testimony to the senate [nationalacademies.org] doesn't agree with you. Anyway they are probably the best statistical experts you can find in one place and are certainly not alone in their approval of Mann's work. Furthermore the minor problems they did point out were adressed by Mann in a later publication in Science which you can look up yourself, this is how science works, no?

              The reason I point to that testimony is because it's the half-truth that many psuedo-skeptical, armchair statistitians base their opinions on, whether you in particular realise that or not is irrelevant.

              Quote TFL: "The basic conclusion of the 1999 paper by Dr. Mann and his colleagues was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on icecaps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years
              ....[snip]...
              We also question some of the statistical choices made in the original papers by Dr. Mann and his colleagues. However, our reservations with some aspects of the original papers by Mann et al. should not be construed as evidence that our committee does not believe that the climate is warming, and will continue to warm, as a result of human activities."


              Why anyone would waste money and scientists time by having a senate enquiry on one particular graph is beyond me but whatever the reason it has served to further strengthen Mann's arguments.

              As for the expert you keep demanding, that's not how science does things. Perhaps the NASA links are weak evidence by your standards because most people just rely on their reputation, but if you think they are wrong the onus is on you to provide evidence to the contrary. No matter how many papers I throw at you supporting NASA, you can continue to troll by demanding an individual expert claim an institutional publication which has nothing to do with the credibility of the evidence.

              And since you obviously think you are good at stats why haven't you answered my question? - Under your stated assumptions, what's the probability that Antarctica and/or Greenland is NOT losing ice?
              • Re:If the ice melts (Score:5, Interesting)

                by TapeCutter (624760) * on Saturday April 04, 2009 @07:07AM (#27456437) Journal
                Speaking of taking things out of context, note that psuedo-skeptics have reduced the entire enquiry down to "our committee does not believe that the climate is warming".
                • by microbox (704317) on Saturday April 04, 2009 @09:02AM (#27456843)
                  "our committee does not believe that the climate is warming".

                  Or, if it is warming, we should adapt to the changes instead of addressing economic activity. That's when they show their true colours.

                  Basically all this noise is just a big psychotic roadblock to change.
                • by ArcherB (796902) on Saturday April 04, 2009 @09:23AM (#27456963) Journal

                  Speaking of taking things out of context, note that psuedo-skeptics have reduced the entire enquiry down to "our committee does not believe that the climate is warming".

                  Please do not attempt to speak for us pseudo-skeptics. We are not saying that the climate is not warming. We are not saying that the climate IS warming. What we are saying is that we don't know. So when you say, reduced the entire enquiry down to "our committee does not believe that the climate is warming"., it should read, "our committee thinks the climate is warming. I mean, we're pretty sure. I know we keep saying that we KNOW for sure this time, only to find some boneheaded mistake someone made to either get a grant, political reasons or just stupid. Still, all that aside, we are pretty sure that the climate is warming. And while there is some debate over weather (pun, not grammar) it's warming or not, there is much more debate over why. Oh, and will someone please tell Al Gore to SHUT UP!"

                  • by TapeCutter (624760) * on Saturday April 04, 2009 @10:16AM (#27457269) Journal
                    If your current mod of +5 funny doesn't tell you something then you're not paying attention.

                    However I'm glad you fessed up after our discussion the other day, problem is we regular skeptics don't know what you guys are saying because you keep changing the subject to political conspiracy theories, when that goes nowhere you go back to cherry-picking and red-herrings....I've tried the tinfoil but it simply does not work. Perhaps it's time for you to stop behaving like the shop keeper in Monty Pythons dead parrot sketch.
              • Re:If the ice melts (Score:5, Informative)

                by Rockoon (1252108) on Saturday April 04, 2009 @07:24AM (#27456483)

                If by pointing to Mann's reconstruction methods you mean to imply Mann, et al's hockey stick was debunked you are simply wrong...

                I said exactly what I meant to say, and you are now trying to argue against something I didnt say, which is fine as long as you don't attribute your straw man arguement it to me.

                Now.. don't attribute your strawman arguement to me. OK?

                Furthermore the minor problems they did point out were adressed by Mann in a later publication in Science which you can look up yourself, this is how science works, no?

                I am arguing that the veracity of the current peer review process in this field is so lacking that you do not get to appeal to its authority, that these climate experts have been known for a fact (which you admit) to use faulty statistical methods which slip right by the peer review process that you appealed to.

                You don't get to use the "published in Nature" arguement as valid for their statistical value, since as I pointed out, experts in statistics do not do any reviewing of these papers prior to them being published.

                This is quite simple.

                Accept it, reject it.. I dont really care.. but do not reply with strawman arguements that you attribute to me as if you have some sort of refutation for my actual argument, when you apparently and obviously do not.

                • by TapeCutter (624760) * on Saturday April 04, 2009 @07:54AM (#27456585) Journal
                  Strawman: From your words "A popular example is Mann's flawed" I assumed the bit you were pointing out was a "known problem" from the testiomony and I still do. You did not actually state what argument of yours the link was supposed to be supporting?

                  But now your talking about gross incompetence on a decades long intensive reasearch effort that requires a massive conspiracy by the worlds scientific institutions to cover up? Or are you saying that these same institutions do not understand undergrad stats?

                  Either show me your contra-evidence that asserts Mann is incorrect, the ice caps are NOT melting, or the world is NOT getting warmer. If you can't do that then there are other sites such as freerepublic where you can be intellectualy dishonest.
                  • Re: (Score:2, Informative)

                    by taskiss (94652)

                    NOAA studies suggest that there is evidence dust causes a much greater ocean warming effect than anything mankind can cause.

                    http://www.oceanconserve.org/shared/reader/welcome.aspx?linkid=122714

                    And, link suggests that the effect isn't a "new" revelation

                    http://www.publicaffairs.noaa.gov/pr96/dec96/noaa96-78.html

                    AND... the effect of dust on atmospheric temperature estimates suggest warming might not be as affected as once believed.

                    http://earthobservatory.nasa.gov/Newsroom/view.php?id=21574

                    SO, in conclusion, mo

                    • Re: (Score:3, Interesting)

                      by TapeCutter (624760) *
                      Dust is an areosol that has always been there, human areosols are also known to have a large negative forcing [wikipedia.org] (ie: cooling effect) although as you can be seen by the error bars there are some large uncertainties with various forcings they are not enough to reject the overal conclusion in the net anthropogenic component.

                      "Note that more information isn't needed by those that claim irreversible HIGW afects."

                      Best effort says we stabalise at a doubling of pre-industrial levels by 2050, this means stabalisi
                    • Re: (Score:3, Interesting)

                      by taskiss (94652)

                      To achieve a balance between good stewardship and knee jerk "reactionism", we are required to hold off doing anything until more is known... ...if we don't, that'll be as bad as when rabbits were introduced in australia, termites in hawaii, zebra mussels in the great lakes, etc, etc, etc.

                      Folks just want to "do something" about the "issue", and that is a rallying cry to politicians... which are, in their own way, another bane to out existence we introduced out of ignorance.

                    • Re: (Score:3, Interesting)

                      by Jorophose (1062218)

                      The ice levels of your childhood were extremely high.

                      1950-1970 is not an accurate depection of Earth's ideal climate, stop using it as an example.

                    • if we replant the forests, what are the terrible, terrible consequences?

                      While I support stopping deforestation and support planting more trees, science is all over the park as to whether planting trees will actually absorb more CO2 than what is emitted do to their planting. Some research [heatisonline.org] shows more CO2 is emitted from planting trees than the trees will absorb. I think more research should be done.

                      Falcon

                • do not reply with strawman arguements that you attribute to me as if you have some sort of refutation for my actual argument

                  You don't have an actual argument, you're just attempting guilt-by-association. Whether or not you like the peer review has nothing to do with the validity of the statistics in the paper being discussed. If you want to impugn their statistics, you need to actually discuss said statistics, not just make veiled libelous insinuations about random scientists on the basis of unrelated publications.

              • Re: (Score:3, Interesting)

                by ArcherB (796902)

                And since you obviously think you are good at stats why haven't you answered my question? - Under your stated assumptions, what's the probability that Antarctica and/or Greenland is NOT losing ice?

                While this question was not posed to me, I think I'll take a stab at it anyway.

                I would say, "pretty damn good." Take THIS [icecap.us] graph for example. It shows MORE ice in the southern hemisphere.

                Which is the exact opposite of what THIS [nwsource.com] article states. So, the data doesn't back up the predictions. Strange. Maybe the predictions were wrong?

                Then, there is THIS [icecap.us] graph reporting the average temperatures in Antarctica. Hmmmm. It's going down? So, who is correct here; the predictions or the data? Are you one of th

        • by jabithew (1340853)

          They're both NASA links. I think we can trust them to do their stats.

          • Re: (Score:3, Interesting)

            by Rockoon (1252108)
            NASA?

            The same NASA that went 7 years without ever noticing a problem with their methodology [sciam.com] that was detectable with an open source statistics package?

            The discovery of the real problem was made almost immediately after NASA GISS finally revealed their methods for public scrutiny.

            The same qualities that makes open source good are the same reasons that all of these scientists should open up their work. We re talking about publicly funded science here.. its not supposed to be secret.

            They dont get a fre
            • Re: (Score:3, Interesting)

              by TapeCutter (624760) *
              From your link: "Apparently a NASA team overestimated the average 1998 temps by 0.06 degree Fahrenheit, making 1934 the new hottest year title holder by a slim 0.04-degree margin."

              I and NASA agree with the call for transparency, lets look at the "Heartland Instituite".

              The fact NASA and science in general fucks up every now and then in no way implies you have anything more credible to offer.
          • I hope you get moderated funny, because Christ man, you're talking about an organization that completely destroyed the very expensive Mars Climate Orbiter because they screwed up converting between imperial and metric.
        • Re:If the ice melts (Score:4, Interesting)

          by Ambitwistor (1041236) on Saturday April 04, 2009 @09:29AM (#27457001)

          An error margin greater than 50%? Presuming that this is based on a typical 3 standard deviations...

          Actually, reading the paper [sciencemag.org], it looks to me that 80 km^3 is just 1 standard deviation. (They say the GRACE errors were calculated as 1-sigma, and the ice volume error is obtained by sum-of-squared GRACE errors, so it too is presumably 1-sigma.) If so, a 95% interval includes the possibility of zero volume change (but barely).

          I don't see any statistics experts mentioned in that link, so I gotta assume that we cannot expect a normally distributed error, that in fact they have no idea what the distribution might be.

          Ah, the old "I don't like Mike Mann, therefore nobody in the world except a professional statistician knows what a normal distribution is" argument. Very compelling.

          Anyway, if you want to know about the distribution of the errors, read this [agu.org]. They find that the aggregate residuals are normal, but the RMS errors — after standardizing against the spatial and time dependence of the residuals — are non-normal. They discuss the consequences of making a normal approximation. The normal approximation is what they used in the above Science paper.

      • Re: (Score:3, Informative)

        by Troed (102527)

        sea levels are already rising

        No, they're not.

        "if there is one scientist who knows more about sea levels than anyone else in the world it is the Swedish geologist and physicist Nils-Axel MÃrner, formerly chairman of the INQUA International Commission on Sea Level Change. And the uncompromising verdict of Dr MÃrner, who for 35 years has been using every known scientific method to study sea levels all over the globe, is that all this talk about the sea rising is nothing but a colossal scare story"

        [--

    • The ocean level will not be affected by this, as referenced this article. The salt concentration is a lot different between the ice and the ocean, as the ice is composed of fresh water from precipitation. Like the majority of the Antarctic cap, it's already floating.
    • RTFA and RTFS (Score:3, Informative)

      by BeanThere (28381)

      Never mind the article, it's right there in the summary: "it will not cause a rise in sea level because it is already floating, scientists say"

    • Slightly OT: an interesting doomsday scenario was predicted in the sci-fi thriller novel Icefire, by Reeves-Stevens [barnesandnoble.com], where a rogue faction in the government of a large country detonates a bunch of bombs around the edge of the Wilkins ice shelf to detach it from land, and then detonate a big blast above it, in effect slapping the ice shelf into the Antarctic Ocean and creating a tsunami that threatens to wipe out the Pacific Rim --Hawaii, California, Japan, etc. It's a fast-paced novel about how the protago

  • What's in a Name (Score:2, Interesting)

    I have a burning question. Why is it now called "Climate Change" and no longer "(Man Made) Global Warming"?

    There never was a good war or a bad peace.
                    -- Benjamin Franklin
    • Re:What's in a Name (Score:5, Informative)

      by SuperMo0 (730560) <supermo0@gTOKYOmail.com minus city> on Saturday April 04, 2009 @03:19AM (#27455669)

      Because, to the general public, global warming is confusing. "They're saying we're making the world warmer, so how come I just saw on TV that we're having the coldest winter on record?"

      Climate Change more accurately reflects that it's going out of whack in both directions.

      • by pipingguy (566974) *
        Or is it a question of "Global Warming/Climate Change" being blamed for every "odd" thing that happens in the world's weather? Append to that the "known fact" meme that this is caused by human activity. Since AGW is a fait accompli and such a huge issue, why are those that have questions about the theory, data collection methods, source code for the computer models, etc., shut down by the proponents of the theory?

        Or is Global Warming a convenient boogeyman?
        • by SuperMo0 (730560)

          Or is it a question of "Global Warming/Climate Change" being blamed for every "odd" thing that happens in the world's weather?

          No, it's not. At least, not in this comment thread it isn't. The question was why the shift from the trend of calling it global warming to calling it climate change.

          Please, adjust your knickers and find another place to Diggify.

        • Do you mean the increase in hurricane activity? That actually is caused in part by rising water surface temperatures.

        • Global Warming/Climate Change is either caused by humans or it is not.
          Also, it is either harmful to humans or it is not.

          If it is harmful to us, then it doesn't matter if we caused it, it merely matters if we can stop/prevent it.
          If it is not harmful to us, and it is caused by us, then it's our responsibility, but not as important to us as if it were harmful.
          If it is not harmful to us, and not caused by us, then the only reason to stop it is if we care enough about those species it does harm to use the r
          • by pipingguy (566974) *
            Do you think that vehicles with 10 airbags are "safer"? Is 100% safety desireable or even achievable (remember the law of diminishing returns)?

            All the coming disasters claimed by the alarmists are projected to happen only in 100 years or so. "Ah-ha!" you may say, "You don't care about the future and probably eat newborns and burn kittens for fuel as well, evil denier!"

            I won't admit to eating newborns but the fireplace is nicely stoked, and the mewing is getting annoying. Maybe I'll move to penguins nex
      • Re: (Score:3, Insightful)

        by Coryoth (254751)

        Because, to the general public, global warming is confusing. "They're saying we're making the world warmer, so how come I just saw on TV that we're having the coldest winter on record?"

        Climate Change more accurately reflects that it's going out of whack in both directions.

        This is largely false: things are not going out of whack in both directions, but rather just in one direction -- things are getting warmer. The IPCC clearly states that they expect an increase in the number of extreme warm events and a decrease in the number and severity of extreme cold events. The reality is that climate is still variable, with both warm and cold extremes, especially on a regional scale. A decrease in extreme cold events doesn't mean they won't happen, nor that they won't be very cold, jus

    • by FooGoo (98336)

      I have a burning question. Why is it now called "Climate Change" and no longer "(Man Made) Global Warming"?

      I wonder why it's just not called "the weather" anymore.

      • Re: (Score:3, Insightful)

        by blueg3 (192743)

        The weather is still the weather. What we're talking about is climate. You should've learned the difference before you left elementary school.

    • by YttriumOxide (837412) <yttriumox@@@gmail...com> on Saturday April 04, 2009 @04:06AM (#27455861) Homepage Journal

      Why is it now called "Climate Change" and no longer "(Man Made) Global Warming"? [emphasis mine]

      It hasn't been called "Global Warming" by anyone doing real research in a VERY long time. The mainstream continued to say "Global Warming" for a long time after researchers had stopped using the term, and unfortunately the mainstream didn't catch on until after it became as political as it has, making a lot of the people sceptical of it think that calling it "Climate Change" is a weasel attempt at making it more popular - this couldn't be further from the truth.

      As the other replier pointed out, "Climate Change" is simply a more accurate and less confusing name. It DOES amount to the same thing in the long term and when you look at global scales, but to avoid people saying "it's colder where I am right now, so Global Warming is a myth", "Climate Change" is more sensible.

    • Re: (Score:3, Interesting)

      by mvdwege (243851)

      Because the mean temperature of the entire globe is rising, it used to be called Global Warming. As more study was thrown at it, side effects that a mean rise in global temperature was found to create were a bigger spread between maxima and minima, effects on ocean currents, and possibly effects on hurricane formation and migration patterns. So Global Warming as a description just didn't cover the entire range of phenomena anymore.

      And as pointed out by others, this change in actual scientific terminology is

    • Re: (Score:3, Interesting)

      by Ambitwistor (1041236)

      Scientists have called used the term climate change for decades (I found papers going back to at least the 1960s last time I checked, and that's just from what's available online).

      The term "global warming" is a relatively recent, which was popularized in the media. It came to real public prominence after Jim Hansen's 1988 testimony to Congress, in which he used the phrase. The media as well as environmental groups embraced the term "global warming". The phrase had been used occasionally by scientists as

  • by Centurix (249778) <centurix@NoSPam.gmail.com> on Saturday April 04, 2009 @03:16AM (#27455657) Homepage

    That's a pretty cool job.

    ah, that's better.

  • by KronosReaver (932860) on Saturday April 04, 2009 @03:22AM (#27455683)

    Global Warming due to industry and emissions is a hoax...

    The truth is the planet keeps getting warmer the closer we get to Hell.

    • Re: (Score:3, Insightful)

      by YttriumOxide (837412)
      Is it sad that in this day and age it's entirely possible the parent ISN'T intended as a joke? (it's moderated "Funny" and I assume that was the intention, but it's not so easy to tell any more.)
    • The mediaeval idea was that hell was in the centre of the Earth - which is why you get volcanoes. In Dante's cosmology, Purgatory was a mountain on the opposite side of the Earth from Jerusalem.

      It's remembering this kind of stuff that reminds me why, at bottom, I don't believe the anti-anthropogenic-climate-change brigade; throughout history, the people who opposed the scientists (not the next generation of scientists, the contrarians) have always turned out to be wrong.

  • I have 2 questions.

    According to TFA, the Wilkins Ice Shelf has lost 1,800 km^2 of ice in the past year. This [nasa.gov] article states that the ice shelf is 200-250m thick. This gives volume lost of 360,000 km^3 to 450,000 km^3; 2000m*900m*200m, 2000m*900m*250m (easy numbers). Remaining area = (1800/.14)-1800 = 11057 km^2.

    First question. Is it possible that over time (think glacial timeframe, not human timeframe) that the remaining 11,057 km^2 will rebuild the lost volume? How long is this process? If I remembe

    • Yes, the ice shelf can be rebuilt on glacial time scales (e.g., in the next ice age).

      As for the climate impact of ozone loss, your own Wikipedia link has a decent summary: the net affect appears to be slight surface cooling.

  • by G3ckoG33k (647276) on Saturday April 04, 2009 @04:54AM (#27456025)

    It is hard to get a sense for the scale and the magnitude from the article's pictures. So, I looked it up on Google Earth.

    That "ice bridge" protecting the Wilkins Ice shelf is narrow, only about 2 km wide, or slightly more than mile. And it is that which is breaking up. The floating ice area behind it (i.e. to the east) is huge, about 100x100 km!

    Once that bridge is broken, sea currents may more easily flush that ice into the high seas. And, what the effects will be then, we don't know I guess.

    .

  • The ice shelf is imminently expected to break away from ONE island which is considered part of the Antarctic Peninsula. It will still be connected to another island which is considered part of the Antarctic Peninsula.
  • Seriously, the only reason we hear about these icebergs is due to people using fear to scare mankind into making costly measures to prevent some mythical disaster. Mankind has a remarkable ability to adapt to change. The creatures of this earth also adapt to change. If the conditions are not favorable, they die. Why after all these years of living on this planet do we think we have the ability to stop it? I have seen figures saying more will be spent to ATTEMPT to stop warming than will be spent adapti

  • by ZosX (517789)

    "The planet has a fever" -Al Gore

Make headway at work. Continue to let things deteriorate at home.

Working...