A new method to invert InSAR data to resolve stress changes on a fracture embedded in a 3D heterogeneous crust

TL;DR

This paper introduces a novel finite element-based method to invert InSAR data for variable stress changes on fractures within a complex 3D crust, improving the resolution of subsurface stress variations.

Contribution

The paper presents a new XFEM-based inversion technique that accounts for heterogeneous crust and topography, specifically tailored for InSAR data with noise and masking.

Findings

Synthetic tests demonstrate high accuracy in stress change resolution.

Method effectively handles noisy and masked InSAR data.

Applicable to faults and magma intrusions in complex crust environments.

Abstract

We present a new method to invert variable stress changes of fractures from InSAR ground displacements. Fractures can be either faults or magma intrusions, embeded in a 3D heterogeneous crust with prominent topographies. The method is based on a fictituous domain approach using a finite element discretization of XFEM type. A cost function involves the misfit between the solution of the physical problem and the observed data together with the smoothing terms. Regularization parameters are determined by using L-curves. The method is then reformulated to be applied to InSAR data (masked and noisy), projected in Earth-Satellite directions. Synthetic tests confirm the efficiency and effectiveness of our method.