英国周边城市大小冰山轨迹显示18000年前大型冰盖已崩塌

Nature Communications, 24 April 2025

Deep gouges in the seafloor beneath the North Sea reveal that large icebergs tens of kilometers wide floated along the modern UK coastline towards the end of the Last Ice Age, and may help predict how Antarctica may respond to warming temperatures. The study documents the catastrophic collapse of ice shelves surrounding this British ice sheet 18,000 years ago, as the world entered a period of gradual warming. Warmer air and ocean temperatures drove the ice sheet to a critical threshold, when abundant surface melting fractured the surrounding ice shelves, similar to what happened to Larsen B in Antarctica in 2002, but on a much larger scale. The large icebergs commonly seen prior to this threshold were replaced with many smaller, more frequent icebergs as the ice shelves disintegrated. Glaciers subsequently flowed faster into the ocean, unrestrained by the ice shelves previously holding them in place. Very few examples of complete ice shelf loss have been observed in the satellite era, so these findings provide important evidence of the long-term consequences of ice shelf loss: consequences which could play out in Antarctica should the climate continue to warm from fossil fuel emissions.

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