Antarctica on the verge of collapse

The surface of Antarctica's sea ice has shrunk like never before

by Lorenzo Ciotti
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Antarctica on the verge of collapse

Antarctica on the verge of collapse. The surface of Antarctica's sea ice has shrunk like never before. In fact, its extension is only 2.2 million square kilometers in the Southern Ocean. Already in January the situation had established a new record of negative extension, reaching 3.22 million square kilometres, when the average is around 3.8 million square kilometres.

Christian Haas, head of the Sea Ice Physics Section at the Alfred Wegener Institute, told: "On February 8, 2023, when the ice extent was 2.2 million square kilometers, it was already below previous record low of 2022 and since the melting of the ice is expected to continue until the end of February, it is really difficult to speculate how far this historical low will go.

It should be emphasized that the rapid decline of the sea ice occurred in the last six years is remarkable, since the ice cover had remained virtually unchanged for the previous 35 years. Melting began unabated in December 2022, especially in the Bellingshausen and Amundsen Seas of West Antarctica, and to date the former is virtually ice-free." Helmholtz Center for Polar and Marine Research Geophysical Expedition Manager Karsten Gohl added: "I have never seen such an extreme, ice-free situation before.

The continental shelf, an area as large as Germany, it is completely ice-free. While these conditions are beneficial for our fieldwork, it is worrying when you consider how quickly this change has occurred." The cyclical trend of ice formation and melting follows the seasons: in Antarctica the minimum annual peak is reached towards the end of February.

From that moment on, the arrival of the austral autumn and winter feeds the ice shelf with new ice. In 2022 the minimum was reached on February 25, with a record negative extension. To date, sea ice extent around Antarctica is only 310,000 square kilometers higher than last year's record.

During the month of January, the extension averaged 3.23 million square kilometers: a new negative record for the first month of the year, lower than the record of 3.78 million km2 set in January 2017. Looking at trends over the years, the ice shelf around Antarctica is losing an average of 6,400 square kilometers every year.

Air temperatures at about 780 meters elevation have been 1 to 2 degrees above average since November over a large area of coastline extending clockwise from eastern Wilkes Land through the Ross and Amundsen Sea and over much of the Weddell Sea.