Constraining an Ocean Model Under Getz Ice Shelf, Antarctica, Using A Gravity‐Derived Bathymetry

• Main Authors: Millan, Romain, St-Laurent, Pierre, Rignot, Eric
• Format: Text
• Language: unknown
• Published: W&M ScholarWorks 2020
• Subjects: Biological Sciences Peer-Reviewed Articles; Oceanography; Getz; Getz Ice Shelf; Berry Glacier; Antarc*; Antarctica; Ice Shelf
• Online Access: https://scholarworks.wm.edu/vimsarticles/1950; https://doi.org/10.1029/2019GL086522; https://scholarworks.wm.edu/context/vimsarticles/article/2949/viewcontent/2019GL086522.pdf; https://scholarworks.wm.edu/context/vimsarticles/article/2949/filename/0/type/additional/viewcontent/grl60721_sup_0001_figure_si_s01.pdf

Getz Ice Shelf, the largest producer of ice shelf meltwater in Antarctica, buttresses glaciers that hold enough ice to raise sea level by 22 cm. We present a new bathymetry of its sub‐ice shelf cavity using a three‐dimensional inversion of airborne gravity data constrained by multibeam bathymetry at sea and a reconstruction of the bedrock from mass conservation on land. The new bathymetry is deeper than previously estimated with differences exceeding 500 m in a number of regions. When incorporated into an ocean model, it yields a better description of the spatial distribution of ice shelf melt, specifically along glacier grounding lines. While the melt intensity is overestimated because of a positive bias in ocean thermal forcing, the study reveals the main pathways along which warm oceanic water enters the cavity and corroborates the observed rapid retreat of Berry Glacier along a deep channel with a retrograde bed slope.