Net retreat of Antarctic glacier grounding lines
Net retreat of Antarctic glacier grounding lines
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DOI：
10.1038/s41561-018-0082-z
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发表时间：
2018-04-01
影响因子：
18.3
通讯作者：
Slater, Thomas
中科院分区：
文献类型：
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作者：
Konrad, Hannes;Shepherd, Andrew;Slater, Thomas
接地线是冰盖不稳定性的一个关键指标，因为它们位置的变化反映了与周围海洋的不平衡，并影响内陆冰的流动。尽管由于海洋的融化，几个南极冰川的接地线已经迅速退缩，但记录太少，无法评估这种不平衡的规模。在这里，我们结合了联合收割机卫星高度计观测的冰高度变化和冰几何形状的测量，以跟踪整个大陆周围的地面线运动，覆盖范围是以前调查的三倍。在2010年至2016年期间，在南极洲西部，南极洲东部和南极洲半岛的22%，3%和10%的调查接地线以超过25米/年（-1）的速度退缩（自末次冰盛期以来的典型速度），大陆已经失去了1，463 km（2）+/- 791 km（2）的浮冰面积。虽然到目前为止最快的撤退率发生在阿蒙森海部门，我们表明，松岛冰川接地线已经稳定，可能是由于海洋强迫减弱。平均而言，南极洲快速流动的冰流每变薄一米就后退110米。
Grounding lines are a key indicator of ice-sheet instability, because changes in their position reflect imbalance with the surrounding ocean and affect the flow of inland ice. Although the grounding lines of several Antarctic glaciers have retreated rapidly due to ocean-driven melting, records are too scarce to assess the scale of the imbalance. Here, we combine satellite altimeter observations of ice-elevation change and measurements of ice geometry to track grounding-line movement around the entire continent, tripling the coverage of previous surveys. Between 2010 and 2016, 22%, 3% and 10% of surveyed grounding lines in West Antarctica, East Antarctica and at the Antarctic Peninsula retreated at rates faster than 25 m yr(-1) (the typical pace since the Last Glacial Maximum) and the continent has lost 1,463 km(2) +/- 791 km(2) of grounded-ice area. Although by far the fastest rates of retreat occurred in the Amundsen Sea sector, we show that the Pine Island Glacier grounding line has stabilized, probably as a consequence of abated ocean forcing. On average, Antarctica's fast-flowing ice streams retreat by 110 metres per metre of ice thinning.