Shear wave anisotropy of the northeast Indian Iithosphere

Abstract

Analysis of SKS/SKKS phases in the northeast India region provides the first results using digital data, from the southern side of the India-Asia collision zone. Our analysis reveals detectable anisotropy in the study region, contrary to negligible anisotropy reported in southern Tibet. The direction of anisotropy is E-W within the Himalaya and its foredeep, N-S in the Indo-Burma convergence zone and NE-SW close to the Shillong plateau. While lithospheric deformation due to finite strain induced by collision seems to be the source of anisotropy in the Himalaya and its foredeep, an asthenospheric source is invoked as a causative for the mantle strain in the plate interior. Copyright 2006 by the American Geophysical Union.