SIMULATION OF BASIN-INDUCED SURFACE WAVES USING EMPIRICAL SITE AMPLIFICATION AND PHASE CHARACTERISTICS WITH SPECIAL REFERENCE TO PREDOMINANT LATER PHASES IN CALDERAS

Abstract

Strong motion simulation technique using site-dependent amplification and phase characteristics, whose applicability is already shown for short-period ground motions, is applied to basin-induced surface waves with periods of several seconds. First, empirical site amplification factors are estimated for strong-motion sites in Kyushu region, Japan, including sites in calderas. Then, the tequenique is applied to simulate ground motions from the Kagoshimaken-Hokuseibu earthquake of March, 1997, with special reference to predominant basin-induced surface waves in the calderas at preriods of several seconds. The good agreement between the synthetic and the observed ground motions indicates the applicability of the method to ground motions with periods of several seconds.