SHORT-PERIOD SOURCE SPECTRA INFERRED FROM VARIABLE-SLIP RUPTURE MODELS AND MODELING OF EARTHQUAKE FAULTS FOR STRONG MOTION PREDICTION BY SEMI-EMPIRICAL METHOD

Abstract

The effective stresses on the asperities and backgrounds of the faults should be evaluated in the strong motion prediction for future earthquakes. First, short-period source spectra were inferred from variable-slip rupture models for 12 earthquakes of Mw 5.6 to 7.2 in lands and for 6 large earthquakes of M_W 7.2 to 8.1 in subduction zones. Then, the slip amounts and effective stresses on the asperities and backgrounds were evaluated based on the short-period source spectra inferred in this paper. Here, the statistics of the variable-slip rupture models were adopted that described the ratios of the areas, slip amounts, and effective stresses on the asperities to those on the entire fault. Finally, modeling of faults were presented for two types of destructive earthquakes of M_W 7.3 in lands and of M_W 8.3 in subduction zones with the effective stresses 126 bars and 83 bars, respectively, on the asperities.