Dynamics of Active Subglacial Lakes in Recovery Ice Stream
Dynamics of Active Subglacial Lakes in Recovery Ice Stream
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恢复冰流中活动冰下湖泊的动力学
DOI：
10.1002/2017jf004409
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
K. Nisancioglu
中科院分区：
文献类型：
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作者：
Silje Smith;Basile de Fleurian;N. Schlegel;H. Seroussi;K. Nisancioglu
恢复冰流有相当数量的活跃冰下湖泊，通过卫星测高仪观察，这些湖泊在多年内生长和流失。这些湖泊储存和释放的水可能对控制冰流的速度很重要。我们应用冰下水文模型来分析湖泊的生长和排水特性，以及冰流水文网络的同步发展。我们的输出产生一个很好的匹配模型湖泊的位置和那些使用卫星测高确定的许多湖泊。模拟的冰下系统展示了压力波的发展，开始在冰流颈部和过境到100公里内的终点。这些波浪改变了冰流的水力潜力，促进了冰下湖泊的生长和排水。湖泊排水可能导致大型R通道在持续多年的基底过度加深之间发展。压力波，沿着与湖泊的增长和排水率，不相同的重复多年，由于基础网络的发展。这表明，冰下水文恢复冰流的影响，区域排水发展的规模在数百公里，而不是当地的条件超过几十公里。
Recovery Ice Stream has a substantial number of active subglacial lakes that are observed, with satellite altimetry, to grow and drain over multiple years. These lakes store and release water that could be important for controlling the velocity of the ice stream. We apply a subglacial hydrology model to analyze lake growth and drainage characteristics together with the simultaneous development of the ice stream hydrological network. Our outputs produce a good match between modeled lake location and those identified using satellite altimetry for many of the lakes. The modeled subglacial system demonstrates development of pressure waves that initiate at the ice stream neck and transit to within 100 km of the terminus. These waves alter the hydraulic potential of the ice stream and encourage growth and drainage of the subglacial lakes. Lake drainage can cause large R‐channels to develop between basal overdeepenings that persist for multiple years. The pressure waves, along with lake growth and drainage rates, do not identically repeat over multiple years due to basal network development. This suggests that the subglacial hydrology of Recovery Ice Stream is influenced by regional drainage development on the scale of hundreds of kilometers rather than local conditions over tens of kilometers.