Coupled Seismo-Electromagnetic Interferometry for 2D Homogeneous SH-TE Scenarios

We here explore the application of interferometric principles to the coupled seismo-electromagnetic system. We consider 2D homogeneous space scenarios, and focus on one of the two seismo-electromagnetic propagation modes, the SH-TE mode, where horizontally polarized shear-waves are coupled to the transverse electric mode. We start by presenting the theory for retrieving seismo-electromagnetic Green’s function responses via interferometry by cross-correlation. Using explicit homogeneous space solutions, we numerically investigate the interferometric retrieval of an electric field response and a magnetic field response due to a seismic source. We first study the theoretically desirable circular source configuration, providing illumination from all sides, followed by a more realistic line source configuration, exploiting the interferometric far-field approximation. These two numerical examples prove for the selected source-receiver type combinations, that we can indeed retrieve correct dynamic seismo-electromagnetic 2D SH-TE responses using seismic boundary sources only. This is a promising result for the next step: applying 3D seismo-electromagnetic interferometry in the field.