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The Princess Elizabeth Land sector of the East Antarctic Ice Sheet is a significant reservoir of grounded ice and is adjacent to regions that experienced great change during Quaternary glacial cycles and Pliocene warm episodes. The existence of an extensive subglacial water system in Princess Elizabeth Land (to date only inferred from satellite imagery) bears the potential to significantly impact the thermal and kinematic conditions of the overlying ice sheet. We confirm the existence of a major subglacial lake, herein referred to as Lake Snow Eagle (LSE), for the first time using recently acquired aerogeophysical data. We systematically investigated LSE’s geological characteristics and bathymetry from two-dimensional geophysical inversion models. The inversion results suggest that LSE is located along a compressional geologic boundary, which provides reference for future characterization of the geologic and tectonic context of this region. We estimate LSE to be ~42 km in length and 370 km2 in area, making it one of the largest subglacial lakes in Antarctica. Additionally, the airborne ice-penetrating radar observations and geophysical inversions reveal a layer of unconsolidated water-saturated sediment around and at the bottom of LSE, which—given the ultralow rates of sedimentation expected in such environments—may archive valuable records of paleoenvironmental changes and the early history of East Antarctic Ice Sheet evolution in Princess Elizabeth Land. 

Abstract The bathymetry under the Amery Ice Shelf steers the flow of ocean currents transporting ocean heat, and thus is a prerequisite for precise modeling of ice‐ocean interactions. However, hampered by thick ice, direct observations of sub‐ice‐shelf bathymetry are rare, limiting our ability to quantify the evolution of this sector and its future contribution to global mean sea level rise. We estimated the bathymetry of this region from airborne gravity anomaly using simulated annealing. Unlike the current model which shows a comparatively flat seafloor beneath the calving front, our estimation results reveal a 255‐m‐deep shoal at the western side and a 1,050‐m‐deep trough at the eastern side, which are important topographic features controlling the ocean heat transport into the sub‐ice cavity. The new model also reveals previously unknown depressions and sills that are critical to an improved modeling of the sub‐ice‐shelf ocean circulation and induced basal melting.