Estimation of high-frequency wave radiation areas on the fault plane of the 1995 Hyogo-ken Nanbu earthquake by the envelope inversion of acceleration seismograms

Abstract

We estimated the high-frequency wave radiation process on the fault plane of the 1995 Hyogo-ken Nanbu earthquake (MJMA = 7.2), which was a strike slip event along active inland faults, by the envelope inversion of strong-motion acceleration seismograms. Along the Nojima fault, both high- and low-frequency wave radiation were large. This is explained by the fact that the rupture broke the ground surface here. High-frequency waves were also radiated at the step-over of faults between Awaji Island and the Kobe area. The extent of the source region of frequency-frequency waves roughly matches that of the heavily damaged areas. We inferred that the strong high-frequency waves that came directly from the source was one of the causes of the heavy damage to low-rise structures.