Finite Difference Modelling of Seismic Wave Phenomena within the Earth’s Upper Mantle

Abstract

The analysis of the propagation of elastic waves (seismic phases) plays an essential role for understanding important questions concerning the structure, composition and evolution of the Earth. Since direct observation of the Earth deeper interior is not possible, elastic waves generated from earthquakes or artificial sources are recorded with seismographs, usually located as array at the Earth’s surface, and are analyzed for seismic phases. These phases carry important information about the velocity structure within the Earth. In most cases the direct derivation of a velocity model of the Earth is not possible. To interpret the recorded seismic data and to understand the propagation of a seismic wave field through the Earth, synthetic seismograms are calculated for an initial starting model. These synthetic seismograms are then compared with the observations and the initial model is modified. Again, synthetic seismograms are calculated, until those and observed seismograms are similar enough to stop this iterative process. In this paper we discuss several applications of synthetic seismograms calculated with finite difference schemes that can significantly improve our knowledge about the elastic fine structure of the Earth’s crust and upper mantle. Finite difference schemes had previously already been shown to be most efficient for high-performance computing on seismological wave propagation tasks [5].