Greenland glacier calves the Arctic’s largest ice chunk in nearly a half-century

One of the largest of Greenland’s marine “outlet” glaciers (i.e. glaciers ending in the sea) has calved an enormous “ice island” that reportedly extends over 100 square miles.  Not since 1962, when a 250 square mile island was formed from the Ward Hunt Ice Shelf, has such a large area of ice been calved in the Arctic.

I may be on vacation, but climate change isn’t.  So here’s Nick Sundt on WWF’s Climate blog with the story, along with background on Greenland.

Above: Satellite image from Aug. 5, 2010, shows the huge ice island calved from Greenland’s Petermann Glacier. Source: Prof. Andreas Muenchow, University of Delaware.

“In the early morning hours of August 5, 2010, an ice island four times the size of Manhattan was born in northern Greenland,” says Andreas Muenchow, associate professor of physical ocean science and engineering at the University of Delaware’s College of Earth, Ocean, and Environment in a press release (Greenland Glacier Calves Island 4 times the Size of Manhattan, UD Scientist Reports, 6 August 2010) from University of Delaware. The ice island was calved by the Petermann Glacier on the Northwest corner of Greenland.

The Byrd Polar Research Center in Petermann Glacier Front Breakup, July-August 2008 (August 19th, 2008) said that Between 2001 and 2007, 86.8 sq. km (33.5 sq. mi.) broke away from the glacier.  Then in 2008, the center reported that the glacier during the July-August period calved a 29 sq. km. (11 sq. mi.) area of ice. It warned that “more breakup is imminent in the next year, for a large crack has widened while moving toward the calving front.”

Writing in RealClimate’s What links the retreat of Jakobshavn Isbrae, Wilkins Ice Shelf and the Petermann Glacier?, Mauri Pelto said in October 2008 that the glacier’s floating tongue extended 80 km into the sea and covered an area of roughly and 1300 km2 (in area).  “This makes it (by area) the largest floating glacier in the Northern Hemisphere,” said Peltro.

Greenland's Petermann Glacier in 2009. Source: Prof. Andreas Muenchow, University of Delaware.

Above: Greenland’s Petermann Glacier in 2009. Source: Prof. Andreas Muenchow, University of Delaware.

“We expected Petermann Glacier to lose up to 100 sq. km ice area this summer,” the Byrd Polar Research Center reported last October (2009) in Greenland glaciers continue to lose ice area (15 October 2009), “but it held together and even advanced 2 sq km despite warmer than normal surface air temperatures.”

With the massive ice island calved by the glacier on August 5, 2010, the Petermann Glacier made up for lost time.  The glacier lost not just the 100 square km the Byrd Polar Research Center  had anticipated in 2009, but lost at least 260 square km (100 square miles) of ice — about a quarter of its floating ice-shelf.

According to the University of Delaware press release on Friday, the ice island has a “thickness up to half the height of the Empire State Building.” Professor Muenchow said: “The freshwater stored in this ice island could keep the Delaware or Hudson rivers flowing for more than two years. It could also keep all U.S. public tap water flowing for 120 days,”

The calving of the ice island is part of a larger trend of ice loss in the area.  In Greenland glaciers continue to lose ice area (15 October 2009) the Byrd Polar Research Center said:

“Our 2009 area change survey of 34 of the widest Greenland marine-terminating glacier outlets from the inland ice sheet is complete. We find a net marine-terminating ice area loss of 109 sq km. The total net cumulative area change from year 2000 (when our survey begins) to 2009 is -990.2 sq. km, a loss equivalent [to]… an area more than 11 times the area of Manhattan Is. (87.5 sq. km) in New York, USA. The marine-terminating ice area change for these glaciers is -106 sq. km per year, the 2009 loss being within 3% of the linear fit. In other words, and as you can see below, the loss rate has been nearly constant. Though, on a glacier by glacier basis, the loss rate is not constant.”

Above: cumulative annual area changes for 34 of the widest Greenland ice sheet marine-terminating outlets.  Source: Byrd Polar Research Center.

To put the Petermann Glacier’s latest ice island in perpective, the island’s area of at least 260 sq. km is well over twice what all 34 glaciers surveyed by the  Byrd Polar Research Center have been losing annually (-106 per year).

Climate Change is accelerating the rate of ice loss from Greenland — and the ice loss is adding to sea level rise.

As we reported in our earlier post, Warm Ocean Waters are Speeding Greenland Glacier Melt (21 Feb 2010), the floating ice of outlet glaciers is vulnerable to basal melting by seawater circulating under the ice.  The glaciers are melting much faster from below than they are from above  where warm air temperatures drive the melting. In its report, Abrupt Climate Change, the U.S. Global Change Research Program (USGCRP) in December 2008 highlighted the potential importance of such melting.  “The interaction of warm waters with the periphery of the large ice sheets represents one of the most significant possibilities for abrupt change in the climate system,” it said.

Writing in RealClimate’s What links the retreat of Jakobshavn Isbrae, Wilkins Ice Shelf and the Petermann Glacier? (2008), Mauri Pelto explained that a key to Petermann’s major ice losses during the last decade is thinning of the glacier’s floating tongue of ice.  That weakens the ice, increasing ice losses through calving. The melting and calving together reduce the downward pressure of the glacier at the grounding line where the floating portion of the glacier meets the rest of the glacier that rests on land.  As that downward pressure at the groundlng line is reduced, the glacier can move more quickly  to the sea.  Ultimately, more ice mass is lost to the sea and the glacier recedes.

We reported in Dramatic Ice Loss Spreads to Northwest Coast of Greenland (23 March 2010) that the region was losing much more ice in the area where the Petermann glacier is located.  “Our speculation is that some of the big glaciers in this region are sliding downhill faster and dumping more ice in the ocean,” said John Wahr, a coauthor of Spread of ice mass loss into northwest Greenland observed by GRACE and GPSpublished in Geophysical Research Letters (19 March 2010).  Shfaqat Abbas Khan, lead author of the article, says:  “If this activity in northwest Greenland continues and really accelerates some of the major glaciers in the area — like the Humboldt Glacier and the Petermann Glacier — Greenland’s total ice loss could easily beincreased by an additional 50 to 100 cubic kilometers (12 to 24 cubic miles) within a few years.” [emphasis added].

Above: The mass changes of the Greenland Ice Sheet (GIS) for the period April 5, 2003 – July 25, 2009.  The spatial variation in surface mass is shown in centimeters equivalent height of water. The time variation of the GIS mass (in Gigtons) is shown in the x-y plot insert.  Source: NASA/Goddard Space Flight Center Scientific Visualization Studio.

Dr. David Carlson, Director of the International Polar Year International Program Office said in a statement before the Senate Foreign Relations Committee hearing on “The Global Implications of a Warming Arctic” in May 5, 2009:  “A clear consensus has emerged during IPY [International Polar Year] that the Greenland Ice sheet will disappear as a consequence of this current global warming.”  Carlson added that a “very plausible outcome” is  “a meter or more of sea level rise in this century from Greenland alone.”

— Nick Sundt

Related Posts:

Online Resources

Greenland glacier calves island 4 times the size of Manhattan, UD scientist reports.  Press release (6 September 2010) from Univeristy of Delaware.

Petermann Glacier front breakup, July-August 2008.  Posting (August 19th, 2008) in MODIS Studies of Greenland, by Byrd Polar Research Center

What links the retreat of Jakobshavn Isbrae, Wilkins Ice Shelf and the Petermann Glacier? By  Mauri Pelto in RealClimate (7 October 2008)

In Greenland glaciers continue to lose ice area.  Posting (15 October 2009) in MODIS Studies of Greenland, by Byrd Polar Research Center

Spread of ice mass loss into northwest Greenland observed by GRACE and GPS. By Shfaqat Abbas Khan, John Wahr, Michael Bevis, Eric Kendrick and Isabella Velicogna in Geophysical Research Letters, vol. 37 (19 March 2010).

WWF Climate Change Blog

Extreme Ice Survey.  “The Extreme Ice Survey is the most wide-ranging glacier study ever conducted using ground-based, real-time photography.”  See its photos of the following glaciers in the same region as those that were the focus of the research reported in Nature Geoscience:


26 Responses to Greenland glacier calves the Arctic’s largest ice chunk in nearly a half-century

  1. This is, overall, a very good article. I am pleased to see that you have linked to the University of Delaware’s press release dated August 06 2010.

    I predicted this calving as “any day soon” July 22 2010 and published a report of the event August 05 2010.

    According to the rules of priority in science, my August 05 publication trumps any August 06 press release.

    Please see my articles as proof of priority so that you may correct the article:

  2. Colorado Bob says:

    Patrick is correct , I read about this event on the night of the 5th at his site.

  3. Dan B says:

    It seems odd to have an academic spat over first rights of the news of the slow end of a habitable planet.

    Then again friends at a party today had no response to the news that thousands of miles of Eastern Europe and Russia are suffering from unprecedented heat. There’s no framework for discussing either our future prospects or the dire conditions of the present.

    Instead they reverted to small talk.

  4. richard pauli says:

    Also carefully watched is the Pine Island Glacier in Antarctica. It has about 250 kilometers of floating, destabilizing ice sheet that is about 500 meters thick. It may be going soon.

    So the ocean surface covers about 139.5 million square miles.

    With all this ice melt going into the ocean, it is possible to do the math on sea level rise.

    drip, drip.

  5. Prokaryotes says:

    Why isn’t this a ultimate wake up call?

    “a meter or more of sea level rise in this century from Greenland alone.”

    “The freshwater stored in this ice island could keep the Delaware or Hudson rivers flowing for more than two years. It could also keep all U.S. public tap water flowing for 120 days,”

  6. Prokaryotes says:

    The “constant” loss rate “plotted” to Co2 uptake

  7. Prokaryotes says:

    Gravity data collected from space using NASA’s Grace satellite show that Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002. The latest data reveal that Antarctica is losing ice at an accelerating rate, too.

    I read somewhere that antarctica holds a lot of methane – i.e. lake vostok.

  8. Mike#22 says:

    The Hill reports on Congressman Markey:

    “An iceberg four times the size of Manhattan has broken off Greenland, creating plenty of room for global warming deniers to start their own country,” Markey said in a statement. “So far, 2010 has been the hottest year on record, and scientists agree arctic ice is a canary in a coal mine that provides clear warnings on climate.”

    Anthony has kicked off the naming contest with “Deniersburg” but that sounds more like the capitol not the country.

    Isle of Fools?

  9. Lewis Cleverdon says:

    The genocidal profiteers who fund, empower, and propagandize denial to extend shareholder profits are not fools – they’re criminals – and those who cannot face the reality of society’s impacts and so cling to denial are their grossly irresponsible dupes.

    “Graft Island” would thus seem a fitting name for this massive but very temporary platform of melting ice.



  10. Lewis Cleverdon #8

    ‘The genocidal profiteers who fund, empower, and propagandize denial to extend shareholder profits are not fools – they’re criminals – and those who cannot face the reality of society’s impacts and so cling to denial are their grossly irresponsible dupes.’

    I agree as does Eric Pooley quoting Jim Hansen in ‘The Climate War’ page 271:

    ‘Then Hansen took on the power barons, “I’ve been trying to get the attention of the people who could solve the problem, the captains of industry,” he said. “The CEOs are smart enough to know what the actual situation is. The science is clear and yet the public is not aware of that,” thanks to the “contrarians who these fossil fuel companies put forward to confuse the public… If they continue to do that, they are guilty of crimes against humanity and nature. This should be made very clear. They should not be able to pretend that they didn’t know. Because we do know.”’

    Crimes against humanity indeed and already unfolding! Time to start breathing down their necks starting with Fox ‘entertainment-that-subs-for-news’.

  11. catman306 says:

    Last night, NPR’s ATC had a story about the glacier and about wallace Broecker and therefore about global warming. As in Pakistan, water is going over the top of the dam; soon all America will be hearing SOME truth about climate change.

  12. Dan B: this is not a ‘minor spat’.

    I predicted that this amount of ice would calve, and I predicted it July 22 2010 as: “any day soon”.

    I am deeply concerned about the plight of people everywhere who are, even as I write these words, losing their homes, their crops, their lands and even their lives because an organized network of propagandists has been deliberately opposing action for sustainable economics since at least the 1960s.

    I hope you will agree that my words on the perils of ‘business as usual’ and workable solutions to the CO2 problem will carry more weight with politicians if I am properly credited by the media and influential bloggers with having at least a modicum of knowledge about climate.

    In science, priority talks, opinion walks.

  13. David Smith says:

    #9, Lewis, & #10, Lionel, Not only are they criminals (individual and corporate)in my opinion, but the status of most favored citizens was recenty endowed to them by the infamous supreme court decision that gave corporate citizens all rights as individuas with few of the responsibilities. This may have been a legal decision but it was done with full knowledge of the justices as to what the big energy companies are up to. These justices share responibiity for what may be the end of modern human civilization. They should be apoligizing to us for this decision.

    Do others think “The Climate War” is a good book?

  14. Raul M. says:

    About the subject of flat earthers.
    In listening to science lectures, I am noticing that
    some people are obviously able to understand science
    more quickly than other people.
    Yet in listening to politics, there is evidence that
    the decisions that societies have made in the past
    are not easy to change.
    And so we as a people make a physical and emotional
    The response?
    In earlier days a leader may not have wanted to have
    it known that there were others more adept at learning.
    For one thing how would a leader know which other was able to
    know the truth of a situation, the proper decision to be
    made, as well as the truth of the distinction of roles
    of action.

  15. Raul M. says:

    And so being a member of the not so quick to learn
    group of citizens, I too make my guess as to who
    could be smarter and more able to make good decisions
    as to the direction of actions I should take.
    I have been told that my comfort is of primary concern,
    and that it is up to me to make sure that happen.
    Having to relearn societal decisions may be too
    difficult for many who have chosen to follow the
    concept that personal comfort is the primary concern
    and that it is up to oneself to make it happen.
    Or that the leader of the family has very difficult
    time with the same situation.

  16. dhogaza says:

    Patrick, Joe didn’t write the article, he’s simply copied the article at the WWF site he’s linked to. You should e-mail the author of that piece.

  17. Lou Grinzo says:

    Once again, I see an online discussion in which people are asking of this latest hair-raising event will be “the” alarm that wakes us and (finally) gets us to take action on climate change.

    Short answer: No, it’s not even close.

    Long answer: No, it’s not close, and the reason is as basic as economics 101: These events are happening very far away from the consumers and voters and politicians and businesspeople in the US, China, and India. They may as well be on Mars, at least according to the perception of the people in those groups. (There will be effects here in the US, even if only in terms of higher food prices because Russia is losing about 1/3 of its wheat harvest this year and has banned exports for this year, which is spiking wheat prices. But people here haven’t connected even those meager dots yet.)

    To understand this, you have to think like an economist. That means looking at large groups of people in what many non-economists think of as a very cynical way. (We economists think of it as being realistic and based on empirical evidence.) People respond most decisively to things that they perceive do or will affect them personally. As I’ve pointed out countless times online, how many Americans changed their consumption or voting patterns because of Katrina or the European heat wave of 2003 or the massive die-off of forests in the western US and Canada thanks to beetle infestations or any of the dozens of other “much more likely” events we’ve seen over the last 10 or 20 years? I’d guess that among the people directly affected by those events, the percentage is very small, and for those not so affected it’s virtually zero.

    Yes, the heat and fires currently choking Moscow, plus their awful drought, seem to have turned around the official view of the Russian government. But how long will that last? And what about the opinion in the rest of the world? And how many people will care about the Peterman glacier when they’re deciding whether to buy the mid-size SUV or the ginormous model?

    In order to bridge between the abstract concept of climate change and real world behavior changes, people need to be convinced that there’s a significant benefit to them and the people and things they care about from making those changes.

    A US wakeup call would require a very painful US-based event. A worldwide wakeup call would require something truly terrible, like a massive portion of the West Antarctic Ice Shelf breaking off and instantly raising sea levels by several inches. (And I doubt even that would be enough to convince people.)

    Those of us who know what’s going on see the Peterman calving for what it is; everyone else sees it as an oddity, no more significant than footage of a water skiing squirrel on the local news.

  18. Raul M. says:

    on dept. of transportation based podcast released
    as a University talk night, there was a scientist
    recruited to talk about the rise in water level
    along the northern GoM as it affects Fed. roads.
    It seemed that sea level rise has the attention of the
    Dept. of Transportation because there are many
    Fed. roads progressively impacted both continously
    and on an event basis.
    It is nice that scientists may give guidence to the
    Dept. but I didn’t notice a cure allowed.

  19. Raul M. says:

    on another University talk the implication
    was that those interested could try another
    planet to pursue true sustainability.
    So by choice or situation we seem to have
    the singular choice of group denial.
    It reminds me of the great thinker’s choice
    of the judgment day painting when we all suffer great
    heat and wrath. Seems those not to suffer the
    consequences were some of the ones who had died earlier
    than the depicted event.

  20. Bill W says:

    Re Raul at #19, hmm, I guess we’d better get started terraforming Mars now, so we have someplace to go before Earth ends up like Venus. We might even be able to convince the deniers that this activity is of economic benefit: thousands of jobs for missions to Mars!

  21. Chris Winter says:

    David Smith wrote: “Do others think “The Climate War” is a good book?”

    I thought you’d never ask. ;-)

    It is an excellent book. My review:

  22. Mike#22 says:

    Isle of Denial?

  23. Raul M. says:

    Isle of Denial was a suggestion for the iceberg from
    Greenland of the 5th of this month.
    Found in the comment section of the Huffington Post
    Green section of a comment made by a Gov. Official
    about the recent iceberg having a name and official
    statehood for a group of climate colonialists.

  24. Raul M. says:

    Bill W
    no it’s too far and unknown.
    I’ll still meek out a living here on earth
    as best I can. Still saving up for a gallon
    of infrared radiant barrier paint so I can
    see if some brushed on my cap will help.

  25. Fire Mountain says:

    Never has the failure of our institutions nor the criminal negligence of elites been more evident. If I were a U.S. Senator now, taking my 174K with all the perks, I would feel like a total moral failure. Here in the face of utterly devastating climate impacts and the emergence of climate feedbacks that threaten to push the whole problem beyond the possibility of human control, the institution from which the senators draw their pay and “honorable” title has completely crashed in terms of moral authority, legitimacy or respect. Rotten to the M-F’ing core! I’m calling you out, senator, whether you are one of the evil Republicans who deny the crisis or Democrat weenies who are too cowardly or blind to insist that something has to be done, regardless of your precious and overpaid political careers. You are all throwing our children’s lives down the drain. You are all moral criminals in my eyes. How do you sleep at night?

  26. Prokaryotes says:

    Ice island breaks off Greenland glacier

    A guy from Delaware tell’s a US committee that an ice island four times the size of Manhattan is not evidence of global warming.!

    Read the comments.