Gravity-derived bathymetry underneath the Antarctica Ice shelves
Abstract
Ocean melting has thinned Antarctica's ice shelves at an increasing rate over the past two decades, which in turn has played an important role in the buttressing and stability of ice sheets and their contribution to sea level rise. In several sectors of Antarctica, enhanced intrusion of warm, salty water of circumpolar deep water (CDW) origin by increasing westerlies has forced grounding line retreat, de-stabilization and mass loss. However, a lack of detail on the sub-ice shelves bathymetry has limited our ability to quantify how CDW may reach the ice shelves and glaciers and melt them from below. Here, we use a compilation of 10-km resolution gravity anomalies around Antarctica (Scheinert et al., 2016), combined with multibeam echo sounding data from IBCSO, ocean probe depth data, sea mammal depth measurements, seismic data on ice shelves, and grounding line thickness from BedMachine Antarctica to reconstruct a seamless bathymetry underneath all the ice shelves in Antarctica. We compare the results with early derivations to highlight major differences and the impacts that these differences may have on the modeling of the intrusion of CDW into the ice shelf cavities and glacier grounding lines. We identify areas of uncertainty where more data is critically needed to improve the results. We also present an error map of the bathymetry reconstruction. We expect this new data set to make it more permissible for ice sheet/ocean models to reproduce ice shelf melt processes around Antarctica and thereby improve projections of ice sheet evolution in a warming climate.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC060.0007A
- Keywords:
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- 0798 Modeling;
- CRYOSPHERE;
- 0903 Computational methods: potential fields;
- EXPLORATION GEOPHYSICS;
- 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions;
- GEODESY AND GRAVITY;
- 3010 Gravity and isostasy;
- MARINE GEOLOGY AND GEOPHYSICS