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Basement topography and sediment thickness beneath Antarctica's Ross Ice Shelf
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  • Matthew Davis Tankersley,
  • Huw Joseph Horgan,
  • Christine Smith Siddoway,
  • Fabio Caratori Tontini,
  • Kirsteen Jane Tinto
Matthew Davis Tankersley
Victoria University of Wellington, Victoria University of Wellington

Corresponding Author:[email protected]

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Huw Joseph Horgan
Victoria University of Wellington, Victoria University of Wellington
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Christine Smith Siddoway
Colorado College, Colorado College
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Fabio Caratori Tontini
University of Genova, University of Genova
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Kirsteen Jane Tinto
Lamont-Doherty Earth Observatory, Lamont-Doherty Earth Observatory
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Abstract

New geophysical data from Antarctica’s Ross Embayment reveal the structure and subglacial geology of extended continental crust beneath the Ross Ice Shelf. We use airborne magnetic data from the ROSETTA-Ice Project to locate the contact between magnetic basement and overlying sediments. We delineate a broad, segmented basement high with thin (0-500m) non-magnetic sedimentary cover which trends northward into the Ross Sea’s Central High. Before subsiding in the Oligocene, this feature likely facilitated early glaciation in the region and subsequently acted as a pinning point and ice flow divide. Flanking the high are wide sedimentary basins, up to 3700m deep, which parallel the Ross Sea basins and likely formed during Cretaceous-Neogene intracontinental extension. NW-SE basins beneath the Siple Coast grounding zone, by contrast, are narrow, deep, and elongate. They suggest tectonic divergence upon active faults that may localize geothermal heat and/or groundwater flow, both important components of the subglacial system.
28 May 2022Published in Geophysical Research Letters volume 49 issue 10. 10.1029/2021GL097371