Bathymetry along the periphery of the Greenland Ice Sheet using "Oceans Melting Greenland" (OMG) data
Abstract
Marine-terminating glaciers dominate the evolution of the mass balance of the Greenland Ice Sheet (GrIS) and its contribution to sea-level rise. Widespread glacier acceleration has been linked to the enhanced intrusion of warm waters along the periphery but a lack of detail on the bathymetry of the continental shelf and glacial fjords has limited our ability to quantify how subsurface, warm, salty ocean waters of Atlantic origin (AW) reach the glaciers and melt them from below. Here, we combine NASA's Ocean Melting Greenland (OMG)'s airborne gravity and shipborne multibeam echo sounding data, ocean probe and fishing-boat depth data, and ice front glacier thickness from BedMachine Greenland, to reconstruct a seamless bathymetry extending from the edges of the continental shelf, to the glacial fjords, and the glacier fronts in northwest (NW), northeast (NE) and southeast (SE) Greenland. We find a complex network of deep valleys conducive to glacial fjords, however, with profound differences across regions. We find a complex network of deep, connected channels in NW, but few, broad and shallow channels in SE, and a sinuous pathway for Atlantic Intermediate Water in NE. Our study demonstrates the practicality of using airborne high-resolution gravity surveys, constrained by discrete depth data offshore and BedMachine Greenland on land to provide a modern data set on bed topography that will revolutionize our understanding and modeling of ice sheet-ocean interactions and the past, present and future contribution of Greenland Ice Sheet to sea level rise. In particular, the new map describes pathways for AW to reach the glaciers in some regions versus blocking sills in others, and a seamless connection with bed topography beneath grounded ice.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C22A..03A
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE;
- 0776 Glaciology;
- CRYOSPHERE