Jakobshavn Isbrae: Mighty Greenland glacier slams on brakes

From the BBC

By Jonathan Amos BBC Science Correspondent 14 May 2019

Jakobshavn Glacier in west Greenland viewed by the Copernicus Sentinel-2 mission on 29 April 2019

Image copyright Copernicus Sentinel data (2019)/Esa Image caption Jakobshavn in April this year: The glacier is an important drainage outlet for the Greenland Ice Sheet

European satellites have detailed the abrupt change in behaviour of one of Greenland’s most important glaciers.

In the 2000s, Jakobshavn Isbrae was the fastest flowing ice stream on the island, travelling at 17km a year.

As it sped to the ocean, its front end also retreated and thinned, dropping in height by as much as 20m year.

But now it’s all change. Jakobshavn is travelling much more slowly, and its trunk has even begun to thicken and lengthen.

“It’s a complete reversal in behaviour and it wasn’t predicted,” said Dr Anna Hogg from Leeds University and the UK Centre for Polar Observation and Modelling (CPOM).

“The question now is: what’s next for Jakobshavn? Is this just a pause, or is it a switch-off of the dynamic thinning we’ve seen previously?”

Elevation change on the glacier

Image copyright CPOM–A. E. Hogg Image caption Change in height: There was a marked change after 2013

The glacier is sited in southwest Greenland. It’s famous for its spectacular production of icebergs – colossal blocks calve from its terminus and drift down its fjord, out into Disko Bay and onwards to the North Atlantic.

More than likely, it was Jakobshavn that spawned the iceberg that sank the Titanic.

Scientists’ interest in the glacier lies in its role as a drainage outlet for the Greenland Ice Sheet. It’s a key channel for the export of ice that can then raise global sea levels.

Read the full story here.

66 thoughts on “Jakobshavn Isbrae: Mighty Greenland glacier slams on brakes

  1. Can’t possibly be a ‘pause’. No such thing according to climate alarmists.

    ~Ahem~

  2. Surprising to see this reported on the Uber-green BBC! However, the rest of the site is peppered with alarmist nonsense today like every other day!

      • Would have been easy enough ‘Jakobshavn joins the rest of the world’s glaciers by shrinking!’

    • The report had fancy graphics and even some animation from the ESA. What’s not to like. I don’t think anyone at the BBC understood that this is a bad thing for their cause.

    • Can’t you see the news stories in the future, saying things like, “as the ice builds up due to manmade climate change, sea levels will plummet. Port cities will be devastated as the sea recedes kilometers away. As new cities are built adjacent to the newly-formed coastlines, at costs of trillions of dollars, the old port cities will become huge ghost towns of broken dreams and shattered futures. Fresh demands are being made by third-world countries for richer nations to rebuild their port cities, to atone for the damage caused by the use of fossil fuels by industrialized countries.”

      They will never give up. Since the climate WILL change, they will claim victory regardless of the change.

      • If this just happens to show up on one or two satire sites and the Snopes site, do you want attribution? Just wondering since I intend to steal this to repost if you don’t mind.
        If you do object, I will not repost. This is good stuff!!!

  3. That’s a whole BBC story that doesn’t blame something on global warming. A historic first?

  4. The punchline is at the end of the report: “It’s a key channel for the export of ice that can then raise global sea levels.” Interesting study of a glacier fed by a very thick continental glaciar system. But wait a minute, a glacier mover, downhill so towards the sea, due to pressure from accumulating ice in the head zone. If snow is accumulating at the head of the glacier, converting to ice due to burial pressure, then flowing downhill, the system may well be balanced with respect to global sea level. That is, the water deposited as snow at the glacier head may offset the ice that ends up in the sea and melts. Don’t sell your beachfront house just yet.

  5. Jakobshavn isbrae is in Disko Bay which is hardly “south-west Greenland

    And the retreat has not been nearly as steady as it is usually described. – Look at this diagram from Wikipedia:

    https://en.wikipedia.org/wiki/Jakobshavn_Glacier#/media/File:Jakobshavn_retreat-1851-2006.jpg

    Notice the odd spacing of the years? The fact is that almost the entire retreat over the last century happened in two short (warm) periods 1930-1946 and 2001-2012. There is no line in the diagram for 1946, but there is an USAF air photo that shows that the glacier front was at that time essentially the same as in 2001. The glacier front then advanced a bit until some time in the ‘50s and then was almost static until 2001 when it started retreating quickly until 2012, then it slowed down drastically and has now started advancing slightly.

    The 1946 Trimetrogon air photo that is never diagrammed is fig. 11 in this paper:

    https://kuscholarworks.ku.edu/bitstream/handle/1808/17295/VanderveenC_JG_54(184)131.pdf;sequence=1

    Incidentally the USAF photographed essentially all of Greenland in 1946. It would be easy to compare those photos with modern satellite images and show how much the ice cap has shrunk, but no climate scientist seems to be interested in that for some unknown reason….

    • Are those USAF photos available? Would be an interesting research project to compare them with those of today.

  6. The glacier is rapidly melting into the sea? Climate Change!
    The glacier behaviour is altering?
    Climate Change!
    The glacier has stopped moving?
    Climate Change!
    ………

  7. An eyeball integration of the volume over the area adjacent to the glacier outflow says what?

    • It says that Jakobshavn Isbrae is minuscule compared to the Greenland Ice Sheet… 😉

      • However it does drain about 7 % of the whole icecap, sort of a ice Mississippi. Greenland is bowl-shaped which means that much of the icecap drains through a small number of fiords.

        • Rather, “means that only a very little of the icecap can “flow” out to the sea through several very small orifices (valleys) in the surrounding mountains.”

          Yes, it flows. But very, very slowly. Greenland’s high central ice dome is many thousand meters higher than the surrounding mountains. But the center is also several hundreds of kilometers from those valleys. Yet the flow through these valleys is “kilometer per year” for a valley only a few thousands meters wide. The ice cap “draining” into that valley (providing the pressure so it flows at all) is hundreds of kilometers across, thousands of sq kilometers in area.

        • Yes, one to a few kilometers per year are typical flow rates for outlet glaciers. Higher speeds than that only occur for surging glaciers which can actually move fast enough for the movement to be visible to the naked eye. I know, I’ve seen it.

  8. Is it a pause? Is it a switch off?

    I’ll tell you what it is: you don’t understand the behaviour of such gletchers at all. Forget your addictive models and go back to collecting observations.

  9. This, too, will be adjusted away by some “calibration” or “measurement” error correction.

    • Good point, NavarreAggie. No doubt they will have to adjust the length of the meter to show the glacier is moving again.

  10. What terrible articles.

    It was moving at 17km/year, now it’s moving at… what speed? Can no one tell us that?

    It slammed on the brakes. It’s moving much slower. Is that 15km/year or 1km/year?

      • “Must be worse than they want to admit”

        We don’t see polar bear stories any more, and we’re never told how much methane will actually run up temperature. There are probably other examples of the behavior.

  11. “It’s a complete reversal in behaviour and it wasn’t predicted”

    Every time it’s “not predicted”. Every time. It just keeps happening!

  12. “It’s a complete reversal in behaviour and it wasn’t predicted,”

    …but the science is settled. Right?

    • CO2 is a fickle and selective gas. Its impact is not based on atmospheric fraction or distribution, but instead its effects reflect exactly (and only) local-scale variability of all significant garden-variety weather events. How it does this remains a bit unclear, as it’s almost impossible to differentiate how CO2 weather differs from Non-CO2 weather events. Let alone how the minor fraction of human CO2 contributions in particular are existentially dangerous to all life on earth, but otherwise rest assured the science is quite settled and has been settled for years.

      97% of politicians and UN parasitic buttshines can not be wrong.

  13. “It’s a complete reversal in behaviour and it wasn’t predicted,” said Dr Anna Hogg from Leeds University and the UK Centre for Polar Observation and Modelling (CPOM).

    Aha, that’s what they call “settled science” 😀

    • Exactly Krishna!

      ““It’s a complete reversal in behaviour and it wasn’t predicted,” said Dr Anna Hogg”

      As if!
      Since when have any alarmist predictions occurred as predicted?
      Especially considering how alarmists refuse to accept the influence of cyclical natural causes.

    • 97% of GLO-BULL warming alarmists agreed that they don’t know what is going on & then also said that it is worse than they thought.

      • If its melting its bad news, if its growing its bad news – Nat Geo

        There are some really mentally unwell people working at nat geo, and it;s a bit tragic they are not getting the medical support they need, much like Eric Holthaus, I don’t find it funny either, Holthaus is an adult Greta Thunberg.

  14. “NASA’s Oceans Melting Greenland (OMG) project”

    This is a thing apparently. A result of NASA only hiring alarmist activist scientists for the past 20 years.

    Nat Geo and NASA cli sci are cancer
    AS a result I never really believe anything I read from NASA without checking it first, such is the damage done to their reputation with dodgy cli sci and facts from their history that have come out in the past decade, the worst being the incompetent killing of a shuttle crew cos funding

  15. It’s definitely worse than we thought !

    Climate change now causes unexpected reversals of behavior !

      • aye, as with all such socially cancerous movements, there is “one enemy” that causes all harm.

        DDT ban probably killed more people than Stalin or Hitler individually.
        CO2 scam is killing people today, in winter with energy poverty, farmers who wont give up their land for palm oil and bio fuels in south america and africa. Women in africa who have to use wood fires because of insane eco imperialism and more we are no doubt not aware of as it is not reported.

        Environmentalist eco loons are fine with killing humans, no really, they are.

        I can feel Eric Holthaus’ tangible desire for hurricanes to kill many so he can feel validated and say he told us so, it’s really sick, and I am not being hyperbolic, he’d think it was for the greater good (as long as it;s not him and his doing the dying for the cause)

  16. Svend-Erik Henriksen told me back in 2008, when he was still alive and working in Greenland, that the rate of ice calving from the coasts of Greenland is virtually always due to accumulated snow and ice pressuring the white stuff “over the edge”. He explained that it is basically like when you continue purring gravel on the top of a gravel heap. There can be a bit of melting in the summer, but this is essentially not worth talking about. Precipitation is the main factor.

    Sven-Erik used to be in the bomb squad in the Danish military, and later worked for DMI (Danish Meteorologic Institute) in Greenland, where he got a shared Nobel Price. Svend-Erik was an amazing analytic. Shortly after he retired and returned to Denmark, to enjoy his retirement, he sadly unexpectedly died. I miss our long emails and conversations.

    • He explained that it is basically like when you continue purring gravel on the top of a gravel heap.

      I’m sure your friend knew this analogy differed from the “accumulated snow and ice pressuring” explanation.
      In the USA, the term “angle of repose” is used to reference the sliding/slumping of a granular material, such as gravel.

      Internal Plastic Deformation (IPD) is a term describing much of what goes on in a mass of ice. Here is a link for those not familiar with the topic.
      Deformation and sliding

      Here is the Wikipedia entry for Angle of repose

  17. “It’s a complete reversal in behaviour and it wasn’t predicted,” said Dr Anna Hogg from Leeds University and the UK Centre for Polar Observation and Modelling (CPOM).

    This the totality of climate science in a nut shell. She said it well.

    • I think what they mean by “…it wasn’t predicted”, was “We actually predicted something else, but we were wrong in our prediction”. However, the first sounds nicer and less judgmental, wouldn’t want to upset anybody.

      Note the real factual distortion here. “…it wasn’t predicted” could mean that “we failed to make any prediction about what was going to happen”, or it could mean “We predicted something else would happen and we were wrong”. At you see in my initial statement, my money’s on a failed prediction, not failure to make any prediction.

  18. We saw this about 6 weeks ago (thanks to WUWT). The NASA/JPL news release:
    https://www.jpl.nasa.gov/news/news.php?feature=7356 said:

    The glacier is still adding to global sea level rise – it continues to lose more ice to the ocean than it gains from snow accumulation – but at a slower rate

    Which would require a lot of supporting information about upstream snow accumulation, which I suspect they didn’t have, but they “know” it anyway. Being climate scientists, there’s a lot that they know without actual observations.

    I suppose that “it’s marginally not quite as bad as we thought” is as close to a retraction that we’ll ever see from climate science.

    The NASA/JPL article, which is a lot more informative than the BBC, went on to explain that the warm Atlantic current that had been causing the Jakobshavn to retreat had now turned cold. Which sounds like saying that the AMO has now entered its cold phase. And makes me wonder what the rest of the West Greenland glaciers are doing.

  19. Could it be that the Sun is quiet. It takes about three years for the Solar heat absorbed at the Equator to move to the poles. And, Greenland is receiving less Solar energy.

    This is not a mystery except to the clowns that hitched their wagon to the CO2 hoax.

  20. The Atlantic Multidecadal Oscillation (AMO)is transitioning from its warm phase to its cool phase. In other words, the North Atlantic sea surface temperatures are cooling, like they do every 25 to 30 years or so. The glacier sped up during the warm phase of the AMO. It will now tend to be slower in the cool phase.

    It’s natural. It’s expected, except by the natural climate change deniers, who are currently running the climate science asylum.

  21. Accelerated in the 30s early 40s … expanded during the “Ice Age Cometh” period and then shrunk again with 90s warming….termination was about at the same place as 1946 in 2001..now its growing again. Analysis: almost all warming to the present took place before 1946. There was a steep worrying cooling that the climateers erased. The Pause is unequivocally real and the hard braking of the glacier a cooling period in progress.

    This Jakobshavn is better than all the proxies that have been used in climate science but the Clime Syndicate won’t use it. Indeed it isnt behaving according to debunked theory.

    The only palpable proof of man caused climate change is the “Great Greening^тм” and it is alm8st taboo to mention it. They come out swinging every decade to say the greening is real bad and then clam up again.

  22. FTA:

    “Scientists’ interest in the glacier lies in its role as a drainage outlet for the Greenland Ice Sheet. It’s a key channel for the export of ice that can then raise global sea levels.”

    Q1. So where does the mass of water in the glacier come from that, when it ends up in the Atlantic Ocean, raises global sea levels?

    A1. From the atmosphere, from whence the snowfall that builds glaciers emanates.

    Q2. So where does the water in the atmosphere come from that produces snow that builds glaciers?

    A2. From the oceans.

    Closed loop … conservation of matter … what goes up, must come down.

  23. “It’s a complete reversal in behaviour and it wasn’t predicted,” said Dr Anna Hogg from Leeds University and the UK Centre for Polar Observation and Modelling (CPOM). –

    Poor thing! Probably can’t even predict which way the wind blows, either. Get her bundled into a parachute, give her a couple of MREs and a few bottles of water and drop her off. She might learn something if she got outside once in a while. When she gets an understanding of how ice and the world really work, she can go back to her nice warm office and warm up again.

    Maybe we’ll see glaciers rebuilding in Montana, Wyoming and Utah, too. That would be too cool!

  24. If this keeps up, lol for ‘science studies’ that would
    explain the rise of sea levels slowing or even stopping.

    For example, the ocean floor may be spreading resulting in deeper depths. Anything to possibly hide that the warming may have stopped.

  25. When CACC predictions fail to occur, the predictor can always say as per Alexandra
    Cortez : “Oh you silly billies, it was just a joke”

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