Using airborne radar data to identify basal crevasses and their effects on ice hydrofracturing
Abstract
Over the past two decades, Antarctic Peninsula ice shelves have experienced catastrophic collapses, resulting in acceleration of outlet glaciers into the ocean. Ponding of melt water on the surface and hydrofracturing is one of the leading hypothesis for the cause of these ice shelf collapses. When water penetrates on either surface or basal crevasses, it imposes additional stresses on ice, causing significant deepening, and enhanced iceberg calving. However, large uncertainties exist in calving models due to the complex interactions between crevasses, climate forcing, ocean warming, and ice-shelf characteristics. Here, we use IceBridge radar data to map crevasses and channels at the base of the ice shelves in the Amundsen Sea region, particularly under Thwaites Glacier to infer basal conditions and investigate the impact of warmer ocean currents on basal crevasses. In order to understand the controlling mechanisms of hydrofracture, we also present lab experiments which visualize the propagation of hydrofractures in brittle solids driven by fluid injection. Gelatin is used as an analog material for ice due to its brittle and elastic properties. We show that the scaling law for fracture propagation based on linear elastic fracture mechanics agrees well with our experiments for a range of injection rates and elasticity of the solid. In the future, we plan to use water on laboratory built ice and held under shear to understand the mechanisms and orientations on fracture formation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C51F1132L
- Keywords:
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- 0768 Thermal regime;
- CRYOSPHEREDE: 0770 Properties;
- CRYOSPHEREDE: 0776 Glaciology;
- CRYOSPHEREDE: 0794 Instruments and techniques;
- CRYOSPHERE