An ice shelf the size of New York has completely collapsed in Antarctica

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Global warming is very real, extreme climatic events are multiplying, at the image of the record temperatures recorded last week at the two poles of the Earth. The temperature in East Antarctica reached minus 20,8 degrees Celsius, more than 40 degrees Celsius higher than the seasonal norm. After only a few days, satellite imagery captured, the 15 march,
the dramatic end of a large ice shelf in this region of Antarctica , the “Conger” barrier. Illustration of what our future holds for us.

The platforms glacial forms (in English ice shelves), or ice barriers , are a peculiarity of Antarctica, although they are also found in Greenland and Canada. These are pack ice (frozen sea water) on which glaciers have settled by compacting the snow. When they break, they give rise to flat icebergs. Thus, they are extensions of ice caps that float above the ocean, playing an important role in retaining the interior ice.

Andrew Mackintosh, ice sheet expert and director of the School of Earth, Atmosphere and Environment at Monash University in Australia, explains: “If they collapse, inland ice flow accelerates and causes sea level rise”.

The Conger Ice Shelf, which was off the east coast of Antarctica at side of the (much larger) Shackleton platform — named in honor of Ernest Shackleton — completely disappeared on 15 March. It was approximately 1200 square kilometers, or barely smaller than Los Angeles and about a third the size of the Larsen B ice shelf, which disintegrated into 2022.

Unprecedented, dramatic and rapid disappearance

The collapse was captured by satellite imagery and shared on social networks by Dr. Catherine Colello Walker, scientist at NASA and the Woods Hole Oceanographic Institution. The images show that the platform remained intact for a period of three months in January 2022 and shattered like a piece of glass in the last two images, which were taken barely a week apart in March 2022. According to the National Ice Center, an American agency monitoring the platforms, the disintegration of the pack ice gave birth to an iceberg of nearly 11 km long on 18 km wide, baptized C-40, which then broke into two pieces.

satellite image conger platform
Les données satellitaires montrent que l’iceberg C-38 s’est détachée de la plate-forme de glace Conger, lors de son effondrement en Antarctique. © USNIC

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Satellite data shows that iceberg C-30 broke off from the Conger Ice Shelf when it collapsed in Antarctica. ©USNIC

Admittedly, this is not the first time that the continent has seen an ice floe disintegrate. In 2002, the Larsen B pack ice, stable for over of 000 000 years, collapsed. Nevertheless, what makes the recent collapse significant is that the Conger Platform is located in the eastern part of Antarctica, a region that has until now been considered a massive, immobile and cold block of ice, by Researchers. C. Walker states that although the Conger Ice Shelf is relatively small, “it is one of Antarctica’s most significant collapse events since the early 2002 when the Larsen B pack ice disintegrated”.

The Conger pack ice has been shrinking gradually since the mid-1990s 2000. As of March 4 of this year, the pack ice appeared to have lost more than half of its area compared to January measurements.

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The Conger pack ice in January 2022, to the right ; in March 1200, left. © Catherine Collelo Walker/Twitter

However, Dr. Catherine Colello Walker points out: “ This does not ‘probably won’t have huge effects, but it’s a sign of what could happen‘. Indeed, the Earth’s average surface temperature has increased by one degree Celsius since the 19th century due to climate change, enough to increase the intensity of droughts, heat waves and tropical cyclones. And in general, the poles warm up faster.

A heat wave responsible for the collapse?

As mentioned above, Antarctica has recently experienced unusual extreme heat, of 18 at 40 °C above the ordinary average for this time of year. The heat was caused by an “atmospheric river”, a huge stream of warm air passing through the area. This atmospheric phenomenon corresponds to air corridors transporting large quantities of vapor over long distances, which therefore trapped the heat on the continent.

Whether Antarctica’s high temperatures caused the sea ice to collapse remains unclear, however, but scientists will need to examine how extreme temperatures have altered the environment around Conger. A. Mackintosh states: “We need to better understand how the warm period influenced melting along this whole sector of East Antarctica”.

Antarctic research has mainly focused on the West Antarctica, as it is much more accessible and has been the subject of well-funded expeditions from the US and UK Antarctic Divisions. But the extreme warming of March has put East Antarctica in the spotlight and revealed the need to better understand the region and its response to human-induced climate change.

Other collapses to come

Helen Amanda Fricker, professor of glaciology at the Scripps Polar Center, said three calving events — when chunks of ice break off from the edge of a glacier — have occurred in the East Antarctica in March. In addition to the collapse of the Conger Ice Shelf, there were smaller calving events from the Totten Glacier and the Glenzer Ice Shelf. She says: “ Much of East Antarctica is restricted by ice shelves, so we need to keep an eye out for all the ice platforms there ”.

Matt King of the Australian Center of Excellence for Antarctic Science says: “We will see more ice shelves break in the future with global warming”. They will be much larger than Conger’s, trapping a lot of ice and thus seriously raising global sea levels. Indeed, scientists are particularly concerned about the future of the Thwaites Glacier, which is the size of Florida — nicknamed the “apocalyptic glacier” —, approximately 100 times larger than Larsen B and which contains enough water to raise global sea levels by more than one half meter.

M. King concludes: “

The rapidity of the breakup of the pack ice [Conger] reminds us that things can change quickly. Our carbon emissions will impact Antarctica, and Antarctica will come back to bite the rest of the world’s coasts, and it could happen sooner than we think”.

Even if the formal evidence of the implication of the heat wave on the collapse of the Conger platform are not there yet, the climate emergency is no longer to be demonstrated and our future seems to be compromised in much shorter timeframes than expected.