Image of the Day: CRAAAACK! SPLIT! A Giant Iceberg Calves from Antarctica (Again…)

By Tom Yulsman | November 15, 2013 5:22 pm
Iceberg calving Pine Island Glacier Antarctica

A major iceberg cracked off the Pine Island Glacier in Antarctica between Nov. 9 and 11, 2013. (Source: NASA Earth Observatory)

It has been anticipated since October, and now a large iceberg has finally split away from the Pine Island Glacier in Antarctica.

This is one big chunk of floating ice — 21 by 12 miles, or 252 square miles. (That’s a bit smaller than the city state of Singapore.) The Landsat 8 image above, from NASA’s Earth Observatory, shows it beginning to drift away on Nov. 13. (For more EO images of the event, go here.)

This is by no means the first such large iceberg to calve from the glacier. A similar sized chunk cracked off and floated away just this past July.

The fastest moving ice stream in Antarctica, the Pine Island Glacier flows out of the West Antarctic Ice Sheet. It is thinning rapidly as it discharges more ice into the ocean than any other glacier on the continent. And that rate of discharge has been increasing, possibly related to a warming climate.

In a region that is frozen most of the time, how could warming be having this effect? The answer: water. Relatively warm water, to be exact, circulating under the ice shelf at the end of the Pine Island Glacier.

This NASA visualization shows how it works, and also discusses research in which scientists have drilled all the way through the ice shelf to install sensors that monitor temperature, salinity and other factors. (For a detailed explanation, go here.)

The ice shelf at the end of the glacier buttresses the river of ice, slowing its flow into the ocean. But westerly winds have been blowing frigid surface water away from the ice shelf, allowing warmer water from the intermediate layers of the Southern Ocean to well up. This warmer water has been eating away at the underside of the ice shelf. (The orange and yellow moving arrows in the animation above.) And this, in turn, has been weakening the buttressing effect, allowing the glacier to flow faster.

In an interview with Environment 360, Robert Bindschadler, an emeritus NASA glaciologist who led the team that drilled into the ice shelf, summed it up this way:

We’re firmly of the opinion that heat is getting to the ice and causing these major changes. So even if you isolate Antarctica somewhat on the surface from global warming, there’s this back door where heat is still getting to this part of the ice sheet.

Currently, the Pine Island Glacier dumps some 46 billion tons of ice into the ocean every year, and the rate has been increasing by 5 to 10 percent each year.

  • Virtuous2012

    It’s been over 30 years since James Hansen testified before Congress on global warming. If we had acted then, perhaps we would not be at –or past — the “tipping point”.

    But Congress, the best little whorehouse in Washington, listened to its patrons, the oil and auto industries, not to the good of the people they swore to defend.

    QED

    • Buddy199

      Personally, I’m more worried that the comprehensive governmental central planning “fix” for global warming is going to end up as spectacularly off the rails as the comprehensive governmental central planning “fix” for health care.

      • twas brillig

        yah good point

      • Elias Chan-Sui

        So what your saying is that this is why a one party government is superior. No need to haggle over what is necessary. No need to worry about a Party of No. You fix the problem and move on.

  • http://www.parafriv.net/ Para Friv

    New look really weird, I feel very excited and curious, here is the plot will probably never be able to set foot. Prices as I can come here even once.

    • twas brillig

      Translated: Wow this looks really weird (alien). I am very excited and curious about this because here is a plot/area of land we will probably never be able to set foot upon. Priceless if I could come to visit here even once. =)

  • Elias Chan-Sui

    Just like there are a few scientists who argue that we can’t attribute storms to global warming, I suppose we can’t attribute this particular iceberg to it either.

    • Tom Yulsman

      Scientists do not say it is impossible to attribute individual weather events to various causes, including climate change. Researchers are, in fact, making progress in determining the specific factors that contribute to specific rainfall events, droughts, etc. — including the degree to which, if any, climate change has played a role. As to the point about this particular iceberg, maybe read the story again. The whole point is that some scientists believe warming ocean waters are strongly implicated.

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ImaGeo

ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.

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