Two-dimensional Seismic Wave Modeling and Inversion by the Boundary Element Method

摘要

Surface wave methods (SWM) are widely used for the geophysical characterization of geological bodies and tectonic structures in both Earth Sciences and Engineering. SWMs exploit the dispersive nature of Rayleigh waves to indirectly estimate shear wave velocity profiles from surface wave measurements, but they are limited to parallel-layered geometries. To overcome such limitations, we exploit the Boundary Element Method (BEM) to define a new class of geometric inversion models that allows to go directly from raw measurements to estimating the shape of laterally varying soil interfaces. The proposed approach enables a robust identification of the subsurface geometry and it aims at filling the gap between the standard simplistic parallel-layered-based SWM and the more complex three-dimensional Full Wave Inversion (FWI) based on Finite Element Methods. Numerical tests on synthetic data unveil the effectiveness of the inverse algorithm and its applicability to wave measurements. An application to field data is finally presented.