5:15 PM - 6:30 PM

# [SCG63-P28] Development of a method to estimate spatial stress pattern from P-wave first motion data: a preliminary numerical simulation

Keywords:stress field, spatial pattern, P-wave first motion, Bayesian estimation

The development of this method is currently at preliminary stage, and thus only a numerical simulation has been done. For the simplicity of the simulation, a case where hypocenters and seismic stations are located in a two-dimensional space (i.e., plane) is considered; one is horizontal and the other is vertical. Also, the direction of the intermediate principal stress (sigma2) and that of a fault plane of each earthquake are supposed to be vertical to the considered plane. The spatial variation of the plunge of the direction of the maximum principle stress (sigma1) is assumed to be follow a particular pattern (and consequently, the direction of the minimum principle stress sigma3 is also determined). Under these conditions and assumptions about the directions of a fault plane and seismic slip as described above, datasets of P-wave first motions are generated. Then, the proposed Bayesian approach is applied to these datasets. As a result, the estimated spatial pattern almost agrees with the one assumed in the generation of the simulation datasets, which suggests the validity of developing this Bayesian approach.