Numerical simulation of present day tectonic stress across the Indian subcontinent

Abstract

In situ measurements of maximum horizontal stress (SHmax) in the Indian subcontinent are limited and do not present regional trends of intraplate stress orientation. The observed orientations of SHmax vary considerably and often differ from the plate velocity direction. We have simulated orientation and magnitude of SHmax through finite element modeling incorporating heterogeneities in elastic property of the Indian continent and plain stress approximation to understand the variability of SHmax. Four different scenarios are tested in simulation: (1) homogeneous plate with fixed plate boundary (2) homogeneous plate with boundary forces (3) heterogeneous plate with fixed boundary (4) heterogeneous plate with boundary forces. The estimated orientation and magnitude of SHmax with a heterogeneous plate with boundary forces in the Himalayan region and an eastern plate boundary comprising the Indo-Burmese arc and Andaman subduction zone are consistent with measured maximum horizontal stress. This study suggests that plate boundary force varies along the northern Indian plate margin and also provides a constraint on the intraplate stress field in the Indian subcontinent.