Glacial Change Ain’t What It Used To Be: Petermann Calves Another Huge Chunk of Greenland Ice

Petermann Glacier has calved another gigantic ice island, larger than twice the size of Manhattan, not quite as large as the calving of two years ago. A study this month found that the melting of the Greenland Ice Sheet is nearing a critical tipping point.”

by Neven, via the Arctic Sea Ice Blog

This second big calving (spotted this time by Arcticicelost80) is another spectacular event on Greenland, after retreats of the Jakobshavn Glacier and lowest reflectivity of the Greenland ice sheet on record (see blog post), leading to unprecedented flooding in the southwest of Greenland.

From the Icy Seas blog:

This morning Petermann Glacier lost another ice island….

The break-off point has been visible for at least 8 years in MODIS imagery propagating at speeds of 1 km/year towards Nares Strait. The fracture also extended further across the floating ice sheet from the northern towards its southern side.

This event is still evolving, Trudy Wohleben of the Canadian Ice Service noticed it first (as in 2010) after reviewing MODIS imagery. Several people in several countries are monitoring and assessing the situation, but a first estimate of its size is 200 km^2 (3 Manhattans), I will revise this figure as soon as I got my hands on the raw data.

Read more here.

Two years ago Patrick Lockerby was the first to tell the world about the big calving that occurred at Petermann Glacier. The Arctic Sea Ice blog followed suit shortly afterwards. The whole event garnered a lot of attention, popularizing the island of Manhattan as an area measurement tool (metre, kilometre, Manhattan). This second big calving in as many years doesn’t come as a surprise, as attested by this article on the New York Times blog from August last year:

Thanks to satellites and other instruments, researchers do know what is happening to ocean and air temperatures in northwest Greenland. They have been warming briskly of late, as global-warming theory predicted decades ago that they would for the whole Arctic.

Dr. Box finds a drastic increase in sea-surface temperatures in the region, and a sharp decline in sea ice. Scientists suspect that warmer water is circulating under Greenland’s floating ice shelves and causing them to weaken. But given the dearth of measurements from beneath Petermann, they do not have hard proof that is what happened in this case.

The breakup of the Petermann ice shelf fits into a broader picture. Many lines of evidence suggest that melting and breakup of Greenland ice, a phenomenon once concentrated on the southern end of that island, has spread to the colder northwest corner. As I reported last year, many scientists are worried about the overall fate of the Greenland ice sheet, especially the prospect that its melting could raise global sea levels substantially.


Dr. Box said another chunk of the Petermann Glacier, this one about twice the size of Manhattan, is now on the verge of breaking loose.

Dr. Box was right. He can now add another image to these two he posted on the blog of the Byrd Polar Research Center blog last year:

In response to the question: How abnormal is this event? Jason notes: “The August 2010 ice calving at Petermann is the largest in the observational record for Greenland” Falkner et al. (2011) scoured the observations and found no evidence of an event this large in scattered observations since 1876. Johannessen et al. (2011) identified the next largest observed Petermann calving event ocurring in 1991, being 58% as large as the 2010 event.

Another image can be added to these two posted in the same BPRC blog post (check out the little Eiffel towers on the left that give an idea about this mamma’s magnitude):

When it comes to those “dearth of measurements” mentioned in the article, Andreas Münchow, a sea-going physical oceanographer from the University of Delaware, is supposed to go to Nares Strait (here to be precise) on the Canadian Coast Guard Ship Henry Larsen at the beginning of August to retrieve instruments that have recorded ocean current, temperature, salinity, and ice thickness data at better than hourly intervals from 2009 through 2012. As Dr. Münchow says in a comment following the blog post I alluded to at the top:

I am crunching numbers … this is a very worrisome event that will make our lives to get a ship recover our instrumentation more challenging and risky. I hope that this ice island will stay inside the fjord until we have safely entered and exited Nares Strait the first 2-3 weeks in August.

— Neven writes for the Arctic Sea Ice Blog. This is an excerpt of a piece originally published at the Arctic Sea Ice Blog and was reprinted with permission.

Related Climate Progress posts:


22 Responses to Glacial Change Ain’t What It Used To Be: Petermann Calves Another Huge Chunk of Greenland Ice

  1. The date in the figure (July-12, 2012) is wrong and should read July-16, 2012 (today). I appologize.

  2. Merrelyn Emery says:

    Joe, could you please release my response to Mark E in the ‘Epic Drought’ posting, 14th July? Thanks, ME

  3. I am not the only one who is scared. Right?

  4. James Benison says:

    Greenland has been losing mass every year for over a decade.

    Unless somebody can point out a magic scenario whereby this mass loss is going to reverse or stop then this tipping point has already been crossed.

  5. Mulga Mumblebrain says:

    I’m putrified-I mean, petrified. I think.

  6. Paul Klinkman says:

    I’m an inventor. A few years ago I invented a device that transfers heat out of the water in a sheltered bay near an ice sheet and puts it into the winter atmosphere. This creates thicker sea ice, which prevents big breakoffs, which slows the progression of the glacier to the sea, which slows sea level rise fairly inexpensively.

    No one in the climate change movement really knows about a number of these possibilities. I see no curiosity from too much of this group about what else is out here, much less an active search for cheap, workable partial answers. That job is left to the Halliburtons of the world, and so naturally the job doesn’t get done.

    Standing on a soap box and yelling “yoo hoo” doesn’t seem to attract anyone’s attention.

  7. Lou Grinzo says:


    Trust me, you’re not alone. I’ve been scared spitless over the accumulating evidence for catastrophic climate change for years, and events like this calving sure aren’t doing much to alleviate that situation…

  8. Ken Barrows says:

    You have some net energy calculations on that? Does it run on solar? Link please.

  9. TomK says:

    So all of this *could* be because of underwater volcanoes in the Arctic and methane releases???

  10. Paul Klinkman says:

    No, it’s a big thermal transfer loop under the surface. Heat from the deep rises, cool sinks. I would consider an optional wind-powered turbine to help accelerate the pumping. The best heat transfer is in the winter when sun is scarce to nonexistent. I suppose there’s some life cycle energy spent building the system, deploying it and taking it out of the water.

  11. Paul Klinkman says:

    Well, the massive methane releases caused by climate change could have helped heat the atmosphere further.

    You’re a hard-working climate change denier, right?

  12. Chris Winter says:

    “You know, three-fourths of the Earth is covered by undersea volcanoes — and how little most of us know about that underwater world…” – Paraphrasing Mike Nelson of Sea Hunt

    So, hypothetically speaking (I don’t know if this is true or not): the volume of CO2 released by volcanoes might be 4 times what geologists have estimated. That still makes it 25 times less than what recent human activities release.

    In order for the recent warming to be caused, even in part, by undersea volcanoes, therefore, their eruption rate must risen substantially in the last 100-200 years (“substantially” being a substantial understatement.) It’s hard to see how that could happen without a similar increase on land.

  13. Paul Magnus says:

    I am sad, angry scared and despondent…

  14. “So all of this *could* be because of underwater volcanoes in the Arctic and methane releases???”


  15. Lori says:

    Very worried and losing hope. If, if, if we had the slightest sign our leaders were acting on thisor making some kind of meaningful effort, that would help alleviate some fears and let us channel our effort/contribution…. but there is nothing.

  16. TomK says:

    Warming of Earth happened before –

    And then remember just a short 12,000 years ago after the warming period Michigan and above was mile deep in ice –

    Just making things balanced

  17. Jim Baird says:

    Paul, I OTEC also converts ocean heat to energy and thus cools the ocean.

    As a fellow inventor I feel your pain and frustration.

    Jim Baird
    Subductive Waste Disposal Method
    Nuclear Assisted Hydrocarbon Production Method
    Global Warming Mitigation Method
    OTEC Counter-current Heat Transfer System

  18. riverat says:

    The trees mentioned in your Science Daily cite were from 2 to 8 million years ago. The current cycle of glaciations didn’t really get started until around 3 million years ago when the Isthmus of Panama rose and cut off the flow of water between the tropical Atlantic and Pacific Oceans. I suspect those trees are from that time.

    The ku-prism link was apparently a report from 1912 of an expedition by Schuchert and White that found fossils of Cretaceous plants on Greenland. The Cretaceous was 65 to 145 million years ago.

    So neither of them is particularly applicable to the current climate and both were long before humans evolved (about 200,000 years ago).

  19. Mulga Mumblebrain says:

    Being ‘balanced’ can mean having a chip on both shoulders.

  20. nyc-tornado-10 says:

    This warming is caused by carbon dioxide emissions from human activity, mostly economic sources of pollution. it is also happening much faster than any other warming, by an order of several magnitudes faster.

  21. RicP says:

    Every system seeks it’s own equilibrium. We seem to have sealed our own fate – the system may just do away with us in order to normalize. But I’m sure the Halliburtons of the world see it that way too…

  22. RicP says:

    sorry – its – not it’s