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Antarctic: ‘No role’ for climate in Halley iceberg splitting

April 5, 2019
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By Paul Homewood

 

h/t Philip Bratby

 

 

The BBC report through gritted teeth!

 

image

When a giant iceberg breaks away from near Britain’s Halley research base, it won’t be because of climate change.

Scientists Jan De Rydt and Hilmar Gudmundsson have spent years studying the area and say the calving will be the result of natural processes only.

The Antarctic station, which sits on a floating platform of ice, was moved in 2017 to get it away from a large chasm.

That crack is now expected to dump a berg the size of Greater London into the Weddell Sea.

It’s not clear precisely when this will happen, but the breakaway looks imminent, prompting the British Antarctic Survey (BAS) to withdraw its staff from Halley as a precaution.

As soon as the calving does occur, though, it can be guaranteed that one of the first questions everyone will ask is: what was the influence of climate change?

And the Northumbria University team believes it will be able to answer with high confidence: "There was none."

Jan De Rydt and Hilmar Gudmundsson have built a model to describe the behaviour of the floating ice platform, which is known as the Brunt Ice Shelf.

Image copyright Jan De Rydt Image caption The model explains why Chasm One opened up where it did, and the direction it took

The Brunt is essentially an amalgam of glacier ice that’s flowed off land and pushed out to sea at a rate of about 400m per year.

Incorporating satellite and surface-gathered data, the team’s model reveals how stress is distributed across the 150-250m-thick structure. And it predicts accurately where cracks are likely to develop and the path they will take.

"It all fits together; it’s a very compelling piece of work," says Prof Gudmundsson.

"It shows that the chasm started to grow because of the stresses building up, and they built up because of the natural growth of the ice shelf. The ice shelf itself created this chasm."

The Brunt has never been in quite so advanced a position. The famous explorer Sir Ernest Shackleton mapped its ice front in 1915 and the modern cliff edge is well beyond what he saw. A calving seems overdue.

Graphic of Brunt

The chasm is not the only major split in the Brunt, however. To the east of Halley is a crack dubbed Halloween, after its discovery on 31 October 2016. This fissure is likely to produce its own berg at some point, but, again, this behaviour can be described simply by the developing stresses in the shelf.

"There is no indication from oceanographic or atmospheric data that the climate is changing in the Brunt area," Dr De Rydt told BBC News.

"Our ocean observations are limited but whatever we have doesn’t indicate anything unusual; and our model shows that what we are seeing can be perfectly explained by natural changes in the geometry of the ice shelf."

https://www.bbc.co.uk/news/science-environment-47817510

 

The comparison with Shackleton’s mapping in 1915 is an interesting one, worth remembering when we get nagged about “melting ice caps”.

But there should really be little surprise about any of this. It is the way icebergs have always formed.

The idea that glaciers flow down to the sea, but somehow never break off is infantile.

15 Comments
  1. Malcolm Bell permalink
    April 5, 2019 10:21 am

    All I can say is “Obvious isn’t it?”.

  2. April 5, 2019 10:28 am

    “There is no indication from oceanographic or atmospheric data that the climate is changing in the Brunt area,” Oh dear, more “climate deniers”. There goes their funding.

  3. Roy permalink
    April 5, 2019 10:28 am

    Obviously it’s news to BBC ‘journalists’.

  4. Mark Winthrop permalink
    April 5, 2019 10:41 am

    BBC admit that Climate change is a historical fact. See A History of Ancient Britain part one Age of Ice, broadcast last night. Commentator without battting an eye lid stated that the climate changed a number of times around 13,000 years ago leaving no one living in what was then Britain to be. I rest my case. Should be required educational viewing for all BBC staff.

  5. April 5, 2019 11:02 am

    “It shows that the chasm started to grow because of the stresses building up, and they built up because of the natural growth of the ice shelf.

    Natural growth – there you have it. Wasn’t ‘climate change’ supposed to be causing glaciers to retreat?

  6. Bloke down the pub permalink
    April 5, 2019 11:27 am

    The idea that glaciers flow down to the sea, but somehow never break off is infantile.
    Warmists seem to fail to understand that if big chunks of ice didn’t break off the sheet every now and then, the alternative is that the ice sheet would expand to cover the whole ocean, and then we would be in trouble.

    • dave permalink
      April 5, 2019 11:58 am

      OBVIOULY, there can be no place for influence from ‘a changing climate,’ since the satellites show that the climate, in that particular region, has NOT CHANGED, in the last forty years:

      http://images.remss.com/msu/msu_time_series.html

      Within the above link, simply go to the series called ‘South Polar.’

      A picture is worth a thousand words, or more precisely, a million words of the normal BBC piffle.

  7. Stuart Brown permalink
    April 5, 2019 1:16 pm

    Gritted teeth indeed!

    “As soon as the calving does occur, though, it can be guaranteed that one of the first questions everyone will ask is: what was the influence of climate change?”

    Well, everyone apart from the scientists who are studying it, obviously…

    “And the Northumbria University team believes it will be able to answer with high confidence: “There was none.” ”

    Believes it will be able to, eh?

    Meanwhile in the abstract of the paper, the scientists use words like ‘we show that’ and ‘enhances our general understanding’,

    and:

    “These internal feedbacks, whereby ice shelves generate the very conditions that lead to their own (partial) disintegration are currently missing from ice flow models, which severely limits their ability to accurately predict future sea level rise.”

    Brave people!

  8. April 5, 2019 5:12 pm

    If you’re still around in about 140,000 years, you will be able to see the current geographic marker and the rest of the South Pole research station, follow this ice into the Weddell Sea. The ice sheet on which the entire South Pole Station resides moves about 10 meters per year.
    https://antarcticsun.usap.gov/features/contenthandler.cfm?id=1998

  9. April 5, 2019 8:58 pm

    Reblogged this on WeatherAction News and commented:
    Antarctic doing what it always does

  10. Malcolm Bell permalink
    April 6, 2019 8:00 am

    Thinking about the ”stress build up in the ice” is there not an elegant basic mechanism which you might expect to work faster than it does? The very cold ice is floating on the sea. The sea is warmer than the ice (or it too would be ice). Hence very slowly the sea will
    erode the ice from below where it is in the water. This will cause the ice to sink slightly inducing a progessively increasing bend in the ice. Ice doesn’t bend (much) and so it cracks. Bingo.

    The cracks are a simple function of ice on water. A prediction (an onvious one!) is that the cracks must be parallel to the coast and along a line of near exactly the same age ice. This assumes ice propagation a coastal constant and submarine erosion a constant. A test is, “when the calf breaks off and floats free is there a vertical step between the upper surfaces?” That indicates the degree of reduced buoyancy

    Warming of the sea will of course increase increase the rate of this process. Hence, is it happening faster than previously known? The Shackleton data suggests the reverse, it is slower. If that is the case the southern ocean must be cooler? Not warming.

    I congratulate Northumbria University for their courage. They will be punished severely.

  11. April 6, 2019 4:38 pm

    Reblogged this on Climate Collections.

    • Malcolm Bell permalink
      April 6, 2019 5:41 pm

      Thank you. I look forward to responses, if any.

  12. Svend Ferdinandsen permalink
    April 6, 2019 8:48 pm

    They can not be real climate reserchers. Then they would have said it was collapsing.
    That is the standard word for ice shelves and glaciers that naturally flows out to sea because snow is building up.

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