Complex bathymetry beneath Thwaites and Dotson Ice Shelves revealed by active-source seismic surveys
Abstract
Recent fast retreat and mass loss of Thwaites, Smith and Kohler Glaciers are largely attributed to reduced ice-shelf buttressing due to an increase in sub-ice-shelf melting by the incursion of warm modified Circumpolar Deep Water (mCDW). However, the exact pathway of the intruding mCDW along the seafloor topography remains uncertain because of the relatively low resolution and associated large uncertainty in the current sub-ice-shelf bathymetry modeled from airborne gravity data. Active-source seismic data collected on Thwaites Eastern Ice Shelf and upper Dotson Ice Shelf in the 2019-2020 Antarctic field season as part of the International Thwaites Glacier Collaboration TARSAN project show kilometer-scale features beyond the resolution of the airborne gravity data, which have implications for the sub-ice-shelf ocean circulation. Despite our best effort, the spatial extent of our surveys was limited because of safety and time constraints. Future measurements with Autonomous Underwater Vehicles (AUVs) and by revisits are needed to fully resolve these complex submarine landforms. Additionally, an innovative multi-sensor approach to model the sub-ice-shelf bathymetry beyond the resolution of airborne gravity data is required. This new approach must integrate all available seafloor-depth data (seismic, AUVs, gliders, floats) with airborne gravity data, and be guided by the wavelength, amplitude and directionality of nearby seafloor and subglacial topography observed by higher-resolution measurements.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC053...01M
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE;
- 0774 Dynamics;
- CRYOSPHERE;
- 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERAL