Dhe work revealed by the British Antarctic Survey dates the start of the melting of the 2 largest glaciers in West Antarctica – these of Pine Island and Thwaites – to the Forties. At the time, a intense El Niño (phenomenon leading to abnormally excessive temperatures) had occurred within the jap a part of the South Pacific Ocean. Global warming has solely taken over, says marine geologist James Smith.
Contrary to what one may imagine, this melting is just not as a result of a hotter ambiance. Everything takes place below the a part of the glacier that floats on the ocean. Glaciers represent frozen platforms whose floor space can exceed 1000’s of sq. kilometers – an unlimited amount of ice which slows their course in the direction of the ocean. If this barrier melts below the As a results of a hotter sea, it’s discovering it increasingly more troublesome to comprise them.
An increase in sea and ocean ranges of 1 meter
The particularity of the Antarctic continent is that it’s surrounded by a strong marine present which carries heat waters from the tropics. In locations, the thickness of the ice shelf can lose 10 meters per yr. It additionally breaks to launch icebergs measuring a number of thousand sq. kilometers. A research, revealed in Nature Climate Change, confirms a fast enhance within the waters surrounding Antarctica, no matter greenhouse gasoline emissions.
French and Belgian scientists are additionally involved that recent water from melting glaciers will decrease the salinity of the water, which additional weakens the ice cabinets. This is how we had been in a position to observe, in February 2023, the smallest floor space of ice cabinets (1.788 million sq. kilometers) because the finish of the Seventies.
“ All West Antarctic ice could also be destabilized “, warns Julia Wellner, glaciologist from the British Antarctic Survey. With, finally, a major rise in sea and ocean ranges. The full disappearance of the glaciers of Pin Island and Thwaites would lead to an increase in water ranges of 1 meter. Bitter statement: there’s, thus far, no efficient digital mannequin of Antarctica. As a end result, the longer term habits of the ice cap and its penalties stay obscure §
https://www.lepoint.fr/sciences-nature/la-fonte-ineluctable-des-glaciers-de-l-antarctique-30-03-2024-2556358_1924.php