Warner Roland C, Fricker Helen A, Adusumilli Susheel, Arndt Philipp, Kingslake Jonathan, Spergel Julian J
Australian Antarctic Program Partnership Institute for Marine and Antarctic Studies University of Tasmania Hobart TAS Australia.
Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California, San Diego La Jolla CA USA.
Geophys Res Lett. 2021 Jul 28;48(14):e2020GL091095. doi: 10.1029/2020GL091095. Epub 2021 Jul 14.
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 km. 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 km 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.
南极冰架上积聚的表层融水可导致裂缝延伸至海洋,并有可能导致冰架坍塌,从而使该大陆的冰排放增加。目前对表层融水增加对未来冰架稳定性的影响了解不足。阿梅里冰架南部有一个广泛的地表水文系统,我们展示了来自卫星图像和ICESat-2的数据,这些数据显示2019年冬季那里出现了快速的地表破坏,覆盖范围约60公里。我们将此解释为一个被冰覆盖的湖泊通过冰架排水,形成了一个冰斗,其中心凹陷深度达80米,周围隆起超过36米。挠曲回弹模型表明损失了0.75公里的水。次年夏天,我们观察到冰斗出现短暂的重新蓄水,同时一条狭窄的融水通道(宽20米,深6米)被快速切割。这项研究展示了高分辨率大地测量如何能够探究关键的小尺度冰架过程。