Multi-Static Observations Using a Stationary Phase Sensitive Ice Penetrating Radar to Constrain Temperature and Water-Content Anomalies Across Shear Margins
Abstract
The behavior, evolution, and sea level contributions of outlet glaciers and ice streams is highly dependent on the location and stability of shear margins. However, the physical processes governing their spacing, formation, and migration are not well understood. Recent modeling studies have indicated that shear margin behavior may be controlled by elevated temperatures and water content in the bottom half of the shear margin, while other studies predict that ice shear margins exist over concentrated subglacial water channels. To test these hypotheses and improve our understanding and modeling of processes governing shear margin evolution, we develop and demonstrate a direct measurement technique to constrain the distribution of englacial and subglacial water across shear margins. We use a combination of common midpoint, monostatic, and bistatic radar sounding experiments to sample a diversity of depths and reflection points across a shear margin to determine the water distribution. Here, we present preliminary results from modeling studies and field testing at Store Glacier in Greenland. In the coming seasons this approach will be applied to the Eastern Shear Margin of Thwaites Glacier which separates it from the Pine Island Catchment and is the only topographically unconfined shear margin in the rapidly changing Amundsen Sea Embayment of West Antarctica.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C51F1124B
- Keywords:
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- 0768 Thermal regime;
- CRYOSPHEREDE: 0770 Properties;
- CRYOSPHEREDE: 0776 Glaciology;
- CRYOSPHEREDE: 0794 Instruments and techniques;
- CRYOSPHERE