Persistent flow acceleration within the interior of the Greenland ice sheet
Persistent flow acceleration within the interior of the Greenland ice sheet
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DOI：
10.1002/2013gl058933
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发表时间：
2014-02-16
影响因子：
5.2
通讯作者：
Hubbard, Bryn
中科院分区：
文献类型：
--
作者：
Doyle, Samuel H.;Hubbard, Alun;Hubbard, Bryn
我们展示了距格陵兰冰盖西缘 140 公里处的高海拔地点的表面速度测量值，距其积聚区约 50 公里。年流通速度逐年增加，从2009年的51.780.01myr(-1)增加到2012年的52.920.01myr(-1)，净增2.2%。这些数据还揭示了由季节性融化和冰上湖泊排水驱动的强季节性流速周期，比冬季平均水平高出 8.1%。索尔等人。 （2013）最近认为，消融区域的冰运动是由于在温暖、快速的夏季发展出有效的冰下排水后冬季流量减少而介导的。我们的数据扩展了这一分析，揭示了平衡线高度以上的年流速逐年增加，尽管表面融化增加，但它仍然足够低，足以阻碍厚冰下有效排水的发展。
We present surface velocity measurements from a high-elevation site located 140km from the western margin of the Greenland ice sheet, and similar to 50km into its accumulation area. Annual velocity increased each year from 51.780.01myr(-1) in 2009 to 52.920.01myr(-1) in 2012a net increase of 2.2%. These data also reveal a strong seasonal velocity cycle of up to 8.1% above the winter mean, driven by seasonal melt and supraglacial lake drainage. Sole et al. (2013) recently argued that ice motion in the ablation area is mediated by reduced winter flow following the development of efficient subglacial drainage during warmer, faster, summers. Our data extend this analysis and reveal a year-on-year increase in annual velocity above the equilibrium line altitude, where despite surface melt increasing, it is still sufficiently low to hinder the development of efficient drainage under thick ice.