Rapid Formation of an Ice Doline on Amery Ice Shelf, East Antarctica.
Rapid Formation of an Ice Doline on Amery Ice Shelf, East Antarctica.
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DOI：
10.1029/2020gl091095
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发表时间：
2021-07-28
影响因子：
5.2
通讯作者：
Spergel JJ
中科院分区：
文献类型：
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作者：
Warner RC;Fricker HA;Adusumilli S;Arndt P;Kingslake J;Spergel JJ
南极冰架上积累的表面融化水可能会将裂缝推向海洋，并可能导致它们坍塌，导致南极大陆的冰排放增加。表面融化增加对未来冰架稳定性的影响还没有被充分理解。南部阿莫里冰架有一个广泛的地表水文系统，我们提供的卫星图像和ICESat-2数据显示，2019年冬季那里的表面迅速破裂，覆盖∼60平方公里。我们将其解释为冰盖湖泊通过冰架排出，形成一个冰柱，中央凹陷在超过36米的隆起中达到80米深。弯曲回弹模型表明，失去了0.75亿千米的水。第二年夏天，我们通过快速切开一条狭窄的融水通道(20米宽，6米深)观察到了漏斗的瞬时补充。这项研究展示了高分辨率大地测量如何探索关键的细尺度冰架过程。卫星图像显示，阿莫里冰架上有一个11平方公里的洼地，2019年冬季一个冰盖的湖泊突然排水，形成了一个冰斗ICESat-2。Worldview数据显示，在超过3600万米的静水反弹和抬升中，洼地的海拔下降了多达80米，ICESat-2光子数据描绘了一个新的融水通道，在2020年由挠曲隆起形成的湖溢入冰斗时切割了这条水道
Surface meltwater accumulating on Antarctic ice shelves can drive fractures through to the ocean and potentially cause their collapse, leading to increased ice discharge from the continent. Implications of increasing surface melt for future ice shelf stability are inadequately understood. The southern Amery Ice Shelf has an extensive surface hydrological system, and we present data from satellite imagery and ICESat‐2 showing a rapid surface disruption there in winter 2019, covering ∼60 km2. We interpret this as an ice‐covered lake draining through the ice shelf, forming an ice doline with a central depression reaching 80 m depth amidst over 36 m uplift. Flexural rebound modeling suggests 0.75 km3 of water was lost. We observed transient refilling of the doline the following summer with rapid incision of a narrow meltwater channel (20 m wide and 6 m deep). This study demonstrates how high‐resolution geodetic measurements can explore critical fine‐scale ice shelf processes. Satellite images showed an 11 km2 depression on Amery Ice Shelf as an ice‐covered lake drained abruptly in winter 2019 forming an ice doline ICESat‐2 and WorldView data show elevation fell as much as 80 m in the depression, amidst 60 km2 of hydrostatic rebound and uplift over 36 m ICESat‐2 photon data profiled a new meltwater channel, incised when a lake formed by the flexural uplift overflowed into the doline in 2020