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Detailed Bathymetry of the Continental Shelf Beneath the Getz Ice Shelf, West Antarctica
Author(s) -
Cochran James R.,
Tinto Kirsty J.,
Bell Robin E.
Publication year - 2020
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
eISSN - 2169-9011
pISSN - 2169-9003
DOI - 10.1029/2019jf005493
Subject(s) - bathymetry , geology , ice shelf , iceberg , oceanography , continental shelf , ice sheet , meltwater , sea ice , front (military) , geomorphology , cryosphere , glacial period
The Getz Ice Shelf (GIS) produces major amounts of basal meltwater due to intrusions of warm modified Circumpolar Deep Water (mCDW) beneath the ice shelf. However, multiple cavity openings and complex geography mean that knowledge of bathymetry beneath the GIS is required to understand ice/ocean interactions. We invert NASA airborne gravity data to obtain bathymetry beneath the ice shelf. Our gravity/geology‐constrained bathymetry is a significant advance on Bedmap2 bathymetry. The sub‐ice shelf bathymetry consists of three cavities separated by topographic ridges extending from the ice shelf front to the grounding line. Passages allowing limited circulation of shallow (≲400 meters below sea level [mbsl]) water between cavities are present, but deeper water is confined to individual cavities. Within each cavity, bathymetric troughs (>900 mbsl) extend from the ice shelf front to subglacial valleys beneath the ice sheet. Our analysis of the gravity data also allows us to infer the presence of thick (>500 m) sediments near the grounding line through much of the GIS, as well as variations in the density and/or thickness of the crust underlying the ice shelf.