Penguin Watch Talk

70-Mile-Long Crack Opens Up in Antarctica

  • yshish by yshish moderator, translator

    A huge crack can be seen in the Antarctic Peninsula's Larsen C ice shelf in this aerial image snapped on Nov. 10, 2016, as part of NASA's IceBridge mission.

    foto

    Snapped by scientists on NASA's IceBridge mission, the shot shows a rift in Larsen C, an ice shelf that is floating off the Antarctic Peninsula. When the crack eventually spreads across the entire ice shelf, it will create an iceberg the size of the state of Delaware, according to IceBridge. That's around 2,491 square miles (6,451 square kilometers).

    Link to the whole article on Live Science: CLICK HERE

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  • AvastMH by AvastMH moderator

    😦 😦 😦 - I switched my Christmas tree off. Anything to save our world 😢

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  • gardenmaeve by gardenmaeve moderator

    Another article regarding an ice crack forming in Antarctica: Ice Cracks Force Shut Down of UK Antarctic station

    "A British research station on an ice shelf in Antarctica is being relocated and shut down over the winter because of fears it could float off on an iceberg, the British Antarctic Survey said on Monday.

    Sixteen people who were due to stay during the Antarctic winter between March and November will now be moved out, the BAS said in a statement.

    The Halley VI station, which is made up of eight brightly-coloured blue and red modules built on stilts with giant skis, was built in 2012.

    Seven of the eight modules have been dragged by tractor 23 kilometres (14 miles) inland and off the shelf away from two cracks—one identified in 2012 and the other in October 2016.

    "There is no immediate risk to the people currently at the station, or to the station itself," the BAS said.

    "However, there is sufficient uncertainty about what could happen to the ice during the coming Antarctic winter for BAS to change its operational plans."

    "It is prudent for safety reasons to shut down the station as a precautionary measure and remove its people before the Antarctic winter begins," it said.

    The BAS said it could evacuate staff quickly in the summer months but not in winter with its 24-hour darkness, extremely low temperatures and frozen sea.

    There are currently 88 people on the station, most of them summer-only staff who were already due to leave.

    There have been six Halley research stations on the Brunt Ice Shelf since 1956.

    Ozone measurements at Halley led to discovery of the Antarctic Ozone Hole in 1985 and the station is important for monitoring climate change.

    The BAS said "every effort" was being made to continue scientific experiments underway there."

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  • yshish by yshish moderator, translator

    Thanks, @gardenmaeve

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  • AvastMH by AvastMH moderator

    Dramatic news @gardenmaeve . I am glad that the scientists will be safe. I just hope that the Antarctic ice will survive. We did have an article about icebergs cooling water which encourages the growth of plankton. The plant plankton absorb carbon dioxide and that helps the planet. Fingers crossed 😕

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  • gardenmaeve by gardenmaeve moderator

    Another follow-up report on the long ice crack:
    An excerpt:
    Larsen ice crack continues to open up
    By Jonathan Amos BBC Science Correspondent

    20 January 2017
    From the section Science & Environment 
    

    'The crack that looks set to spawn a giant iceberg in the Antarctic has continued to spread.
    The rift in the Larsen C Ice Shelf has grown a further 10km since 1 January.
    If the fissure propagates just 20km more, it will free a tabular berg one-quarter the size of Wales.

    That would make it one of the biggest icebergs ever recorded, according to researchers at Swansea and Aberystwyth universities, and the British Antarctic Survey. News of the lengthening crack in the 350m-thick floating ice shelf on the eastern side of the Antarctic Peninsula comes from the EU’s Sentinel-1 satellite system.

    Comprising two spacecraft, this orbiting capability can continuously monitor Larsen C no matter what the weather is doing because its radar sensors see through cloud. Their data indicates the fissure now extends for some 175km. But just how long it will take before the 5,000 sq km block finally breaks free is anyone’s guess, says Swansea's Prof Adrian Luckman.

    "The rift tip has just entered a new area of softer ice, which will slow its progress," he told BBC News. "Although you might expect any extension to hasten the point of calving, it actually remains impossible to predict when it will break because the fracture process is so complex.

    "My feeling is that this new development suggests something will happen within weeks to months, but there is an outside chance that further growth will be slow for longer than that.

    "Sometimes rift growth is triggered by ocean swell originating elsewhere, which is also hard to predict."

    When the berg splits away, interest will centre on how the breakage will affect the remaining shelf structure. The Larsen B Ice Shelf further to the north famously shattered following a similar large calving event in 2002. The issue is important because floating ice shelves ordinarily act as a buttress to the glaciers flowing off the land behind them.

    In the case of Larsen B, those glaciers subsequently sped up in the absence of the shelf. And it is the land ice - not the floating ice in a shelf - that adds to sea level rise...' (Continued at the link.)

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  • AvastMH by AvastMH moderator

    Thank you for that report @gardenmaeve. I'm sure we are all very concerned by the news of this massive ice fracture.

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  • AvastMH by AvastMH moderator

    More news of the Larsen C ice shelf fracture and other news from Antarctic ice:

    Understanding the lie of the land/sea/ice in Antarctica

    The great crack in the ice

    Very sobering news. Don't forget to be a careful consumer of earth resources everyone. 😃

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  • gardenmaeve by gardenmaeve moderator

    The ice broke free on Wednesday, I see.

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  • AvastMH by AvastMH moderator

    Very true, gardenmaeve.

    http://www.bbc.co.uk/news/science-environment-40321674

    Let's hope, with every ounce of strength that we have, that the rest of the ice shelf does not collapse as happened to the Larsen A and B ice shelves.

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  • gardenmaeve by gardenmaeve moderator

    The report I read took pains to point out this is not likely to alter sea level since this was floating ice already. 😉

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  • grannieannie by grannieannie

    I have recently completed an online course and learnt that a lot of the ice in West Antarctica is grounded on the sea floor or below sea level on numerous small islands and landmasses. Whereas the East Antarctica ice sits on a large continent size land mass above sea level. This makes the West Antarctic and Peninsula ice more susceptible to changes in sea temperatures (over long time periods!)

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  • yshish by yshish moderator, translator in response to grannieannie's comment.

    Thanks for those information, @grannieannie

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  • gardenmaeve by gardenmaeve moderator

    Yes, thank you, @grannieannie. That fits with the information I have read. 😃

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