Numerical Modeling for Earthquake Source Image: Implications for Array Design in Determining the Rupture Process

Abstract

The aim of this study is to develop a numerical method to evaluate the optimum seismic station distribution for imaging the source rupture process of an earthquake. Based on the beam-forming technique, the source rupture distribution of an earthquake can be reconstructed through theoretical travel time correction and waveform stacking. Numerical tests show that this method successfully reconstructs the main displacement distribution from an assumed source rupture plane. In accordance with assumed fault models, seismic waveforms are numerically generated as input data for further source imaging. From synthetic seismograms, we reconstructed the rupture distribution of these assume earthquake sources, and analyzed error systematically. Results of this study indicate that receiver distribution types really affect the successful reconstruction of the slip distribution. Furthermore, parameters such as dip angles and frequency content also play important roles in reconstructing earthquake sources. The proposed method is simple, inverse efficiently, and no initial condition required. Further applications of this method are suggested to image source rupture from near field strong motion observations and to design seismic array to effectively observe seismic rupture properties.

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