EGU22-10829, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-10829
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Previously unknown topographic features beneath the Amery Ice Shelf, East Antarctica, revealed by airborne gravity

Junjun Yang2, Jingxue Guo1, Jamin S. Greenbaum3, Xiangbin Cui2, Liangcheng Tu4, Lin Li1, Lenneke M. Jong5, Xueyuan Tang1, Bingrui Li1, Donald D. Blankenship6, Jason L. Roberts5, Tas van Ommen5, and Bo Sun1
Junjun Yang et al.
  • 1Polar Research Institute of China, Shanghai, China
  • 2China Aero Geophysical Survey and Remote Sensing Center for Natural Resources, Beijing, China (yang.741@osu.edu)
  • 3Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
  • 4TianQin Research Center for Gravitational Physics, School of Physics and Astronomy, Sun Yat-sen University, Zhuhai, China
  • 5Australian Antarctic Division, Kingston, TAS, Australia
  • 6Institute for Geophysics, University of Texas at Austin, Austin, TX, USA

The seafloor topography 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 seafloor topography of this region from airborne gravity anomaly using simulated annealing. Unlike the current seafloor topography 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 gravity-estimated seafloor topography model also reveals previously unknown depressions and sills in the middle of the Amery Ice Shelf, which are critical to an improved modeling of the sub-ice-shelf ocean circulation and induced basal melting. With the refined seafloor topography model, we anticipate an improved performance in modeling the response of the Amery Ice Shelf to ocean forcing.

How to cite: Yang, J., Guo, J., Greenbaum, J. S., Cui, X., Tu, L., Li, L., Jong, L. M., Tang, X., Li, B., Blankenship, D. D., Roberts, J. L., van Ommen, T., and Sun, B.: Previously unknown topographic features beneath the Amery Ice Shelf, East Antarctica, revealed by airborne gravity, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10829, https://doi.org/10.5194/egusphere-egu22-10829, 2022.

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