22/01/2018

As NASA Reveals Stunning Images, Antarctica Had Record Low Sea-Ice Coverage In 2017

Fairfax - Charles Goodsir

NASA has released stunning photos of the Antarctic ice caps after its most recent expeditions last year.
However, Antarctica had a record-low sea ice coverage of 6.61 million square kilometres in 2017, the US National Oceanic and Atmospheric Administration said in its latest report.
Snow and ice on the Creswick Peaks. The light blue areas on the cliff face indicate melting.  Photo: Nathan Kurtz / NASA / Earth Observatory
In November last year, NASA conducted two missions as part of its Operation IceBridge, which is in its ninth year of flights to map the snow and ice of Antarctica.
On November 4, the IceBridge team flew its "Endurance West" mission, which specifically targets sea ice.
Then, on November 12, a high-priority mission was conducted over the Larsen C Ice Shelf, as it had been significantly reshaped a few months earlier after it shed an iceberg that measured 5060 square kilometres.
During each flight, nearly 8000 photographs were taken, which revealed several large fractures in the ice.
The largest crevice, which measured 21 kilometres long and 11 kilometres wide, was sighted in between the Dyer Plateau and George VI Sound ice caps.
The Dyer Plateau was among the worst affected areas. Several fractures were seen with navy blue coloured areas, which is seawater.
Sheets of ice breaking up and melting in the George VI Sound Ice Shelf.  Photo: NASA / Earth Observatory
Further, the ice caps indicated signs of having thin levels of ice around the edges, which is shown as a grey colour in the photographs.
These images were released days before NOAA declared that 2017 was the third warmest year on record for the globe in the 138 years of recording. 2016 and 2015 were the warmest and second warmest years on record respectively.
A heavily crevassed glacier flows west from the Dyer Plateau.  Photo: NASA / Earth Observatory
The global average temperature for last year was about 15 degrees Celsius, whereas the global average temperature in the 20th century was 1 degree lower at 14 degrees.
NASA, through different methods, said that 2017 was the second warmest year on record. NASA calculates the surface temperature whereas NOAA monitors the air and soil temperature.
A map of the featured Antarctic Peninsula. Points 4 and 5 are the Larsen C Ice Shelf. Points 10 and 11 are the area covering the Dyer Plateau and George VI Sound. Points 6 to 9 are the Cresswick Peaks.  Illustration: NASA Earth Observatory map by Joshua Stevens.
Both agencies concluded that the six warmest years on record have been in the 2010s.
NASA has scheduled another ice-mapping satellite mission for late this year.

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