RADIATION PATTERN AND FMAX OF THE TOTTORI-KEN SEIBU EARTHQUAKE AND THE AFTERSHOCKS INFERRED FROM KIK-NET STRONG MOTION RECORDS

Abstract

Radiation patterns and fmax are evaluated using Kik-net strong motion records of the 2000 Tottori-ken Seibu earthquake and the aftershocks. In order to evaluate frequency-dependent radiation patterns, an empirical model of observed radial-to-transverse ratios (R/T) for aftershocks is constructed as a function of frequency, hypocentral distance and theoretical R/T. Fmax are estimated after removing site effects including soil nonlinearity and forward directivity effects. Based on the results that decay of spectra at frequencies higher than fmax is small and that fmax are not dependent on magnitude, it is pointed out that the effects of source-controlled fmax are small.