Modeling the Seismic Velocities and Anisotropy of Polar Ices exhibiting Various Microstructures: Interplay between Lattice Preferred Orientations, Air Content, and Rock Debris
Abstract
The interpretation of icequakes requires an accurate knowledge of the seismic response of polar ices. The effective elastic properties of polycrystalline ice, and associated seismic response, possibly anisotropic, strongly depend on the ice microstructure. For polar ices, important microstructural parameters are the strongly pronounced crystallographic texture (LPO), with grains c-axes typically oriented towards the in-situ vertical direction or aligned with the vertical plane, the air volume fraction in the firn (open porosity) and down to 1000m depth (close porosity), and the inclusion of sand/rocks coming from the bedrock erosion in the 100m bottom layer. To estimate the seismic response of such ices, we make use of an adapted scale transition model (so-called elastic self-consistent model) that allows estimating the effective elastic properties of polar ices with respect to the microstructural parameters, and the interplay between these parameters. Associated anisotropic seismic response will be discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C31C1539C
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHEREDE: 0728 Ice shelves;
- CRYOSPHEREDE: 0730 Ice streams;
- CRYOSPHEREDE: 0798 Modeling;
- CRYOSPHERE