研究称南极冰架融化速度是先前估计的两倍

Nature, 10 August 2022

This study provides the first comprehensive map of iceberg “calving” across Antarctica; and doubles previous estimates of ice loss due to ice shelf retreat, which has released more than 12 trillion metric tons of ice over the past three decades. Iceberg calving occurs when large sections of ice shelves fracture and break away into the ocean. The rapid loss of ice along the edges of the ice sheet weakens its structural integrity, allowing its huge glaciers to slide more quickly towards the ocean. This enormous pressure further destabilizes ice shelves. For nearly three decades, the Antarctic Ice Sheet has been shedding icebergs faster than they can be replaced. Major regions such as the Pine Island and Thwaites glaciers, which could destabilize the entire West Antarctic ice sheet with additional loss, are highly sensitive to calving. Rising ocean temperatures also erode the base of Antarctica’s ice shelves, making them thinner and weaker; increasing their vulnerability to hydrofracture and partial or complete collapse. Authors underscore that the weakening of Antarctic ice shelves could accelerate global sea-level rise in the near future; and damage marine ecosystems, alter major ocean circulation patterns, and threaten coastal human communities on a global scale.

https://www.nature.com/articles/s41586-022-05037-w