Introduction

Accurate estimation of near-fault strong ground motion from our basic understanding of faulting mechanisms and seismic wave propagation is an important goal in the field of earthquake engineering. In areas where there are no near-fault recordings of strong ground motions, such estimations can be crucial in producing a strong ground motion ShakeMap for emergency response purposes [e.g., Dreger and Kaverina, 2000; Dreger et al., 2005].

The main goal of this study is to develop a deterministic method to simulate temporal variations of slip from geodetic static displacements, and apply this method to derive reliable near-fault strong ground motion for earthquakes. Geodetic observations offer several advantages. Geodetic inversions can independently determine the orientation and fault finiteness quickly, whereas seismic inversions must first determine a moment tensor, and then test both possible nodal planes. Because geodetic slip-model inversions take less computer time than seismic inversions, this method can more quickly predict strong motion when real-time GPS observations are available. For emergency response, even a small improvement in time can be significant. Geodetic data sets also provide redundancy should seismic data sets be sparse or inaccessible in real-time, or difficulties arise in the multistage processing of the seismic data [e.g., Dreger and Kaverina, 2000].

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