Signatures of Seismic Anisotropy in Crustal Terranes: Southeastern California

University Of Southern California, Los Angeles CA

Investigators

Abstract

EAR-9980570 Okaya, David This project is a study to identify the types of vector wavefield signatures that may be observed in crustal refraction/reflection three-component data due to anisotropic terranes within the crust and to use these signatures to map the terrane. The study would a) employ anisotropic wave propagation theory to formulate analytical or numerical expressions of the cumulative anisotropic effects to waveforms along surface-to-surface raypaths typical of crustal scale seismic experiments; b) examine two already-existing datasets collected in regions of known anisotropic layering; c) obtain quantitative measures of uncertainties for isotropic velocity analysis of anisotropic data using synthetic data; and d) examine discriminants for separating the cases of anisotropic effects due to uniform (bulk) anisotropy, anisotropic heterogeneity, and isotropic heterogeneity within the crust. The three-component crustal refraction/reflection datasets are located in southeastern California and both are coincident with outcrops of anisotropic terranes with existing petrophysical measurements to indicate velocity anisotropy.