Finite-Difference Heterogeneous Multiscale Method for the Frequency-Domain Elastic Wave Modelling
Wei Jiang, X. Chen · 2024
Summary The frequency-domain finite difference (FDFD) methods can readily simulate viscoelastic behaviors, such as attenuation and dispersion, of seismic waves. However, the computational memory and time costs for solving the large linear system, which is constructed from the wave equation using a FDFD method, are prohibitive for large-scale and finely discretized models. We propose a FDFD heterogeneous multiscale method (FDFD-HMM) for elastic wave modelling in isotropic media. The method solves elastic wave equation on coarse grids by incorporating fine-scale features in a coarsely gridded model, reducing the dimension of the linear system such that an efficient direct solver can be applied to solve this linear system. Numerical example shows that our method can model the wavefields in a heterogeneous model with satisified accuracy and high efficiency compared to the conventional FDFD method.