Effective Elastic Response and Associated Seismic Anisotropy of Polar Ices Exhibiting Pronounced Crystallographic Texture, and Containing Air and/or Rock Inclusions

Wednesday, 17 December 2014
Olivier Castelnau1, Anne Mangeney2, Amandine sergeant-Boy2, Jean-Paul Montagner2, Eleonore Stutzmann2 and Veronique Farra2, (1)CNRS, Paris Cedex 16, France, (2)Institut de Physique du Globe de Paris, Paris, France
The accurate interpretation of icequakes requires a good knowledge of the seismic response of polar ices. The effective elastic properties of polycrystalline ice, and associated seismic anisotropic response, strongly depend on the specimen 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 bubbles content in the firn, and the inclusion of sand/rocks (coming from the bedrock erosion) in the bottom layer. We make use of a scale transition model (so-called elastic self-consistent model) that allows estimating the effective elastic properties of polar ices with respect to the microstructure parameters. Associated seismic response will be discussed.