Greenland Lakes Could be Speeding Ice Melt

January 27, 2015

In the ebb and flow of climate information, there seems, lately, to be a pulse of new findings relevant to the accelerating melt of ice sheets.

Scientific American:

As happens so often in science, Mike Willis wasn’t actually looking for what he ended up discovering. The glaciologist was combing through satellite and GPS data to see what small, local effects could be clouding satellite measurements of larger changes in Earth’s gravity from ice loss.

What he did not expect to find was a hole twice the size of Central Park in a small ice cap in the northern reaches of Greenland.

“What the heck is that?” he thought when he saw it.

He didn’t think he could possibly be the first person to have spotted it. “Surely someone’s noticed a gigantic hole in northern Greenland before,” he said, but there were no records of it.

Trying to guess what it could be, he and his colleagues ruled out a meteor crater, a volcano, and, as they joked, Dr. Evil’s sub-ice lair. Ultimately, “the thing that fits it best is that it’s a subglacial lake,” he said.

Such lakes of water pool at the bottom of an ice sheet or glacier, and were known to be scattered under parts of Antarctica. But they hadn’t been found yet in Greenland.

Looking through satellite data going back to the 1970s, Willis couldn’t find any sign of the hole until 2006. At that point surface water in the area was flowing in an unexpected direction and disappearing down a moulin right in the spot Willis was looking at. That flow pattern repeated every few years, and then in 2011, “Boom! A big hole appears in the place where the water disappeared,” he said.

Ohio State University:

COLUMBUS, Ohio—Researchers who are building the highest-resolution map of the Greenland Ice Sheet to date have made a surprising discovery: two lakes of meltwater that pooled beneath the ice and rapidly drained away.

One lake once held billions of gallons of water and emptied to form a mile-wide crater in just a few weeks. The other lake has filled and emptied twice in the last two years.

Researchers at The Ohio State University published findings on each lake separately: the first in the open-access journal The Cryosphere and the second in the journal Nature.

Ian Howat, associate professor of earth sciences at Ohio State, leads the team that discovered the cratered lake described in The Cryosphere. To him, the find adds to a growing body of evidence that meltwater has started overflowing the ice sheet’s natural plumbing system and is causing “blowouts” that simply drain lakes away.

“The fact that our lake appears to have been stable for at least several decades, and then drained in a matter of weeks—or less—after a few very hot summers, may signal a fundamental change happening in the ice sheet,” Howat said.

Guardian:

The planet’s two largest ice sheets – in Greenland and Antarctica – are now being depleted at an astonishing rate of 120 cubic miles each year. That is the discovery made by scientists using data from CryoSat-2, the European probe that has been measuring the thickness of Earth’s ice sheets and glaciers since it was launched by the European Space Agency in 2010.

Even more alarming, the rate of loss of ice from the two regions has more than doubled since 2009, revealing the dramatic impact that climate change is beginning to have on our world.

The researchers, based at Germany’s Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research – used 200m data points across Antarctica and 14.3m across Greenland, all collected by CryoSat, to study how the ice sheets there had changed over the past three years. The satellite carries a high-precision altimeter, which sends out short radar pulses that bounce off the ice surface and then back to the satellite. By measuring the time this takes, the height of the ice beneath the spacecraft can be calculated.

It was found from the average drops in elevation that were detected by CryoSat that Greenland alone is losing about 90 cubic miles a year, while in Antarctica the annual volume loss is about 30 cubic miles. These rates of loss – described as “incredible” by one researcher – are the highest observed since altimetry satellite records began about 20 years ago, and they mean that the ice sheets’ annual contribution to sea-level rise has doubled since 2009, say the researchers whose work was published in the journal Cryosphere last week.

 

 

 

6 Responses to “Greenland Lakes Could be Speeding Ice Melt”

  1. redskylite Says:

    Related to this topic is the discovery of a hole discovered in the Antarctica ice, first thought to be meteorite caused – now described as most likely an ice doline in today’s Discovery News — a sinkhole-type pit that appears when meltwater lakes suddenly drain from their bottoms. After the holes discovered in Siberia last year, drunken boreal trees, subsiding tundra buildings, just more phenomena confirming what we already know is happening. Plenty of “Early Warning” signs and signals (from aged photo compares of glaciers, to mysterious craters). Insurance statistics, precipitation records – do we need yet more dramatic signals and proddings to wean us off burning more and more fossils. By the way atmospheric CO2 is still climbing, we are still out of balance.

    http://news.discovery.com/earth/global-warming/melting-not-meteorite-caused-crater-in-antarctica-150127.htm

  2. ubrew12 Says:

    Now that Climate denial is beginning to lose interest and funding, I’m planning to engage in ‘Sea level rise denial’, with funding from Exxon, Chevron, BP, and all those lucrative rightwing think tanks.
    Richard Alley: “Greenland is slipping”
    Me: “No its not! You don’t know that! Show me proof! Greenland will be with us for hundreds of years! Why do you hate America?”

    • jimbills Says:

      “Now that Climate denial is beginning to lose interest and funding”

      I know that your comment is satire, but still, climate change denial isn’t losing its funding. It’s being masked better with a sort of anonymous laundering via avenues like Donors Trust:

      More recent news – Koch 2016:
      http://www.nytimes.com/2015/01/27/us/politics/kochs-plan-to-spend-900-million-on-2016-campaign.html?_r=0

      • dumboldguy Says:

        Here’s some additional “recent news”. The WashPost also reported on the Koch brothers spending plans for 2016, and we can be sure that a lot of that nearly $900 million is going to go to climate denier candidates or their PACs, multiplying the impact of the $35-40 million in your chart several-fold.

        http://wapo.st/1zjGK54

        Freedom Partners is the big Koch umbrella group, and its President Marc Short and other officials talk about the group’s goal being to “make free-market ideals central in American society” and “promoting free-market principles in government, business, and the media”. One does not need an interpreter to understand what that means—–climate change denial is a long way from being starved to death. The environmental rapists want to preserve their bottom lines.

        Also in the WashPost recently—-“Obama opens east coast to offshore drilling”, and more commentary on what the Saudis are up to and its impact—–they say they can “sit on” oil prices for another eight years if need be, and large SUV sales climbed rapidly in the U.S. during the last quarter of 2014. Two steps forward, etc.


  3. […] Greenland Lakes Could be Speeding Ice Melt (Climate Crocks) [emphasis added]: As happens so often in science, Mike Willis wasn’t actually looking for what he ended up discovering. The glaciologist was combing through satellite and GPS data to see what small, local effects could be clouding satellite measurements of larger changes in Earth’s gravity from ice loss. What he did not expect to find was a hole twice the size of Central Park in a small ice cap in the northern reaches of Greenland. […]

  4. dumboldguy Says:

    Neat little post, by the way. Mysterious craters and disappearing lakes are a lot of fun.

    And another piece of the puzzle for us to push around on the table and wonder about. Will we figure it all out before the puzzle gets so heavy that the table collapses?


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