Hem
Illustrationsbild. (Ian Joughin / AP)

Kritisk isbarriär på Antarktis hotar att brista

En isbarriär som hindrar att Thwaites-glaciären på västra Antarktis rör sig mot havet riskerar att kollapsa inom fem år. Det visar en ny amerikansk studie, rapporterar Washington Post.

Barriären har tidigare betraktats som stabil men nya satellitbilder visar hur den håller på att spricka upp på grund av att vattnen den vilar på har blivit varmare.

Redan i dag står avsmältning från Thwaites-glaciären för runt fyra procent av den årliga höjningen av havsnivån i världen. Om barriären skulle brista beräknas hastigheten med vilken glaciären rör sig mot havet att tredubblas.

bakgrund
 
Thwaites Glacier
Wikipedia (en)
Thwaites Glacier, sometimes referred to as the Doomsday Glacier, is an unusually broad and vast Antarctic glacier flowing into Pine Island Bay, part of the Amundsen Sea, east of Mount Murphy, on the Walgreen Coast of Marie Byrd Land. Its surface speeds exceed 2 kilometres per year (1.2 miles per year) near its grounding line. Its fastest flowing grounded ice is centred between 50 and 100 kilometres (31 and 62 mi) east of Mount Murphy. It was named by the Advisory Committee on Antarctic Names in 1967 after Fredrik T. Thwaites (1883–1961), a glacial geologist, geomorphologist and professor emeritus at the University of Wisconsin–Madison. The historian Reuben Gold Thwaites was his father.Thwaites Glacier is closely watched for its potential to raise sea levels. Along with the Pine Island Glacier, it has been described as part of the "weak underbelly" of the West Antarctic Ice Sheet, due to its apparent vulnerability to significant retreat. This hypothesis is based on both theoretical studies of the stability of marine ice sheets and observations of large changes on these two glaciers. In recent years, the flow of both of these glaciers has accelerated, their surfaces have lowered, and their grounding lines have retreated.
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