Finite-Difference Simulations of Seismic Wavefields in Isotropic and Anisotropic Earth Models

Abstract

The analysis of the propagation of elastic waves (seismic phases) plays an essential role in studying the structure, composition and evolution of Earth’s interior. Elastic waves may be generated by earthquakes or artificial sources (explosives). Analysing the recorded wavefields yields information about the medium through which the waves have propagated. Information about the velocity structure within the Earth, provides important constraints on the mineralogical composition. In most cases, however, the direct derivation of a velocity model is not possible. The comparison of synthetic seismograms with observations can be used in the interpretation of the recorded seismic data and for the analysis of wave propagation effects. In this forward-modeling approach, an initial model of the velocity structure is modified until observed and calculated wavefields agree sufficiently well. We discuss applications of wavefield simulations in isotropic and anisotropic elastic media that have improved our knowledge about the elastic fine structure of Earth’s interior. Our modeling is based on finite-difference schemes to solve the elastic wave equation. Efficient implementations of the corresponding code with further examples of seismic wavefield modeling are also given in [11].