Observations of Buried Lake Drainage on the Antarctic Ice Sheet.
Observations of Buried Lake Drainage on the Antarctic Ice Sheet.
复制标题
DOI：
10.1029/2020gl087970
复制
发表时间：
2020-08-16
影响因子：
5.2
通讯作者：
Keenan E
中科院分区：
文献类型：
--
作者：
Dunmire D;Lenaerts JTM;Banwell AF;Wever N;Shragge J;Lhermitte S;Drews R;Pattyn F;Hansen JSS;Willis IC;Miller J;Keenan E
在1992年至2017年期间，南极冰盖（AIS）的冰损失相当于海平面上升7.6 ± 3.9毫米。AIS的质量损失被冰架所减轻，冰架通过调节来自支流冰川的冰流提供了支撑。然而，冰架稳定性受到融水积水的威胁，这可能会引发或重新激活先前存在的裂缝，目前对这一过程知之甚少。在这里，通过探地雷达（GPR）分析在东南极冰架接地区的一个埋藏的湖泊，我们提出了第一个在南极洲通过垂直断裂的湖泊排水事件的现场观测。在湖泊排水事件发生的同时，我们观察到地表高程下降，Sentinel‐1后向散射增加。最后，我们建议，断裂，启动或重新激活的湖泊排水事件在接地区将传播与冰流到冰架本身，在那里他们可能会影响其稳定性。我们提出了第一个通过南极洲水力压裂法快速排水的地下湖的实地观察，在排水之前，通过探地雷达检测到湖底裂缝，并表明湖泊可能已经被预先处理过排水，数字高程模型的遥感分析和哨兵1号微波图像差异提供了额外的湖泊演变信息。
Between 1992 and 2017, the Antarctic Ice Sheet (AIS) lost ice equivalent to 7.6 ± 3.9 mm of sea level rise. AIS mass loss is mitigated by ice shelves that provide a buttress by regulating ice flow from tributary glaciers. However, ice‐shelf stability is threatened by meltwater ponding, which may initiate, or reactivate preexisting, fractures, currently poorly understood processes. Here, through ground penetrating radar (GPR) analysis over a buried lake in the grounding zone of an East Antarctic ice shelf, we present the first field observations of a lake drainage event in Antarctica via vertical fractures. Concurrent with the lake drainage event, we observe a decrease in surface elevation and an increase in Sentinel‐1 backscatter. Finally, we suggest that fractures that are initiated or reactivated by lake drainage events in a grounding zone will propagate with ice flow onto the ice shelf itself, where they may have implications for its stability. We present the first field observations of the rapid drainage of a buried lake via hydrofracture in Antarctica Lake‐bed fractures are detected from ground penetrating radar prior to drainage and suggest the lake may have been preconditioned to drain Remote sensing analysis of digital elevation model and Sentinel‐1 microwave image differences provide additional lake evolution information