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3D Discontinuous Galerkin Elastic Modeling Based upon a Grid Injection Method
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
A versatile method to perform 3D elastic modeling in a heterogeneous target domain based upon grid injection technique is introduced. To perform elastic seismic modeling with a reasonable amount of time, we consider a reduced computational domain embedded in a larger background model in which seismic sources are located. Our aim is to compute repeatedly the full wavefield in the targeted domain after model alteration, once the incident wavefield has been computed once for all in the background model. To achieve this goal, we use a grid injection method referred to as the Total-Field/Scattered-Field (TF/SF) technique in the electromagnetic community. We implemented the Total-Field/Scattered-Field approach in the Discontinuous Galerkine Finite Element method (DG-FEM) that is used to perform modeling in the local domain. We interfaced this method with an with an arbitrary incident wavefield solution. This interfacing requires to modify the numerical fluxes at the boundary between the inner and intermediate domain to guarantee the consistency between the ingoing and the outgoing wavefields in the target. An example of wavefield injection to perform seismic modeling at the lithospheric scale for teleseismic earthquakes by coupling Spectral Elements method and DG-FEM is presented to show the feasibility and to validate our approach.