Extrinsic Elastic Anisotropy in a Compositionally Heterogeneous Earth's Mantle.

ABSTRACT: Several theoretical studies indicate that a substantial fraction of the measured seismic anisotropy could be interpreted as extrinsic anisotropy associated with compositional layering in rocks, reducing the significance of strain-induced intrinsic anisotropy. Here we quantify the potential contribution of grain-scale and rock-scale compositional anisotropy to the observations by (i) combining effective medium theories with realistic estimates of mineral isotropic elastic properties and (ii) measuring velocities of synthetic seismic waves propagating through modeled strain-induced microstructures. It is shown that for typical mantle and oceanic crust subsolidus compositions, rock-scale compositional layering does not generate any substantial extrinsic anisotropy (<1%) because of the limited

SUBMITTER: Faccenda M 

PROVIDER: S-EPMC6472509 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature