FDFK2D: Efficient Two-Dimensional Teleseismic Wavefield Modeling for Receiver Function Analysis Using a Hybrid Method

Abstract

We develop a Fortran package with high programming optimization and parallel computing for simulating high-frequency (>1 Hz) teleseismic wavefields using a hybrid numerical method that couples the finite-difference (FD) and frequency–wavenumber (FK) methods. This method can simulate the interactions of incoming teleseismic wavefields with local heterogeneities but reduce computational region to a much smaller localized domain, which can significantly reduce the computing cost of the high-frequency teleseismic wavefields. The local heterogeneities are allowed to vary arbitrarily in a localized heterogeneous domain. In this package, the geographical locations of earthquakes are permitted, which can consider the real azimuthal effect of the source. Numerical benchmark tests first demonstrate the effectiveness of the developed method for P- and S-wave receiver functions (RFs). The consistent travel times of synthetic and theoretical RFs phases demonstrate its high accuracy. Application on a dense array generally obtains consistent RFs profiles with observed ones and successfully reproduces the observed common-converted-point (CCP) stacking image, which further verifies the effectiveness of the presented method. In addition, statistics of the time-consuming of typical models illustrate the high efficiency of this package, which needs very little computing resources even to be feasible on a laptop.