Larsen C ice shelf breaks

As expected a huge iceberg has split off the Larsen C ice shelf on the Antarctica Peninsula.

The Larsen C Ice Shelf, which is between 200 and 600 metres thick, floats on the edge of The Antarctic Peninsula, holding back the flow of glaciers that feed into it.

Professor Adrian Luckman of Swansea University, lead investigator of the MIDAS project, said:

“We have been anticipating this event for months, and have been surprised how long it took for the rift to break through the final few kilometres of ice. We will continue to monitor both the impact of this calving event on the Larsen C Ice Shelf, and the fate of this huge iceberg.

The iceberg is one of the largest recorded and its future progress is difficult to predict. It may remain in one piece but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters.

Project Midas:  Larsen C calves trillion ton iceberg

A one trillion tonne iceberg – one of the biggest ever recorded – has calved away from the Larsen C Ice Shelf in Antarctica. The calving occurred sometime between Monday 10th July and Wednesday 12th July 2017, when a 5,800 square km section of Larsen C finally broke away. The iceberg, which is likely to be named A68, weighs more than a trillion tonnes.  Its volume is twice that of Lake Erie, one of the Great Lakes.

The final breakthrough was detected in data from NASA’s Aqua MODIS satellite instrument, which images in the thermal infrared at a resolution of 1km, and confirmed by NASA’s Suomi VIIRS instrument.

NASA Suomi VIIRS panchromatic image
from July 12 2017, confirming the calving

The development of the rift over the last year was monitored using data from the European Space Agency Sentinel-1 satellites – part of the European Copernicus Space Component. Sentinel-1 is a radar imaging system capable of acquiring images regardless of cloud cover, and throughout the current winter period of polar darkness.

The iceberg weighs more than a trillion tonnes (1,000,000,000,000 metric tonnes), but it was already floating before it calved away so has no immediate impact on sea level.

Although the remaining ice shelf will continue naturally to regrow, Swansea researchers have previously shown that the new configuration is potentially less stable than it was prior to the rift.  There is a risk that Larsen C may eventually follow the example of its neighbour, Larsen B, which disintegrated in 2002 following a similar rift-induced calving event in 1995.

Dr Martin O’Leary, a Swansea University glaciologist:

“Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable.”

This is a huge iceberg and a big event. Calving of ice shelves is a natural occurrence, but they could be influenced by warming temperatures and they could influence the effects of climate change. These things are difficult to determine accurately.

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12 Comments

  1. Alan Wilkinson

     /  July 13, 2017

    Thank goodness the alarmists have got something to amuse themselves with now that global temperatures have dropped as usual in the year following an El Nino.

    Reply
    • Mefrostate

       /  July 13, 2017

      “Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable.”

      Reply
  2. Zedd

     /  July 13, 2017

    @AW

    Is it really just part of the ‘normal cycle’ that TRILLION ton chunks of ice, are breaking off the antarctic ice sheet (on a regular basis) ? Not that I’ve ever heard !

    Time to “Wake up folks” & cut out the C-C denials… you’re just fooling yourself, not the sane/rational minds, who now accept ‘the times they are a-changin’ 😦

    Reply
    • Alan Wilkinson

       /  July 13, 2017

      Yes. Annual snowfall on Antarctica is hundred(s) of billion tonnes and predicted to increase:

      http://www.earth.columbia.edu/articles/view/3339

      Reply
      • Mefrostate

         /  July 13, 2017

        “They found that the effect of rising temperatures on snowfall has so far been overshadowed by Antarctica’s large natural climate variability, which comes from random, chaotic variations in the polar weather. By mid-century, however, as temperatures continue to rise, the study shows how the effect of human-induced warming on Antarctica’s net snow accumulation should emerge above the noise.

        The expectation of more snowfall is something of a silver lining as temperatures rise. Global warming is already increasing sea level through melting ice and thermal expansion.”

        Reply
  3. Hey Zedd! Tick tock, only 4 years to go till the start of the small ice age! Time to reopen the Coal fields

    Reply
    • Zedd

       /  July 13, 2017

      @bjm1

      actually an ice-age would just PROVE C-C is occurring.. bring it on ! 🙂

      Reply
  4. Maggy Wassilieff

     /  July 13, 2017

    @zedd

    Yep, it’s a very regular occurrence for large floating masses of ice to break up.
    Try this less alarmist report of the Larsen C
    http://www.bbc.com/news/science-environment-40321674

    Reply
  5. Zedd

     /  July 13, 2017

    oh dear, the c-c Ostriches come out again.. 😀

    You would all be cheering Mr Ts withdrawal from Paris convention & his plans to restart the coal fired power stations then ?

    You are all welcome to come have a look at the sea-level along St.Clair/Kilda beach & tell me its just a part of the ‘normal cycle’ too.. now crashing over the seawall on a MORE regular basis !
    *must be just el nino ? :/

    Reply

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