A hybrid method to compute short-period synthetic seismograms of teleseismic body waves in a 3-D regional model

Abstract

We present a hybrid method to simulate the propagation of short-period teleseismic body waves through 3-D regional models. The incident wavefield is computed in an spherically symmetric reference earth model based on the direct solution method. The global and regional wavefields are matched at the boundaries of the regional mesh. In the regional domain, we implement a spectral-element method with absorbing boundaries to cancel the outgoing scattered wavefield. The hybrid method is successfully benchmarked against the direct solution method in the reference earth model iasp91. The potential of the method is illustrated by computing short-period P-wave synthetic seismograms in a 3-D model with a 20 km Moho offset and/or topography on the free surface, focusing on the actual example of the Pyrenees.