Reinterpretation of seismograms obtained by the Kurayosi explosions with the reflectivity method.

Abstract

The record section of the Kurayosi explosions was reinterpreted by comparing it to synthetic seismograms computed by means of the reflectivity method. The inversion of the observed data into a P-velocity depth function was performed mainly for the purpose of accounting for the obscure Moho reflections and the predominant later phases which are observed at distances greater than 200km after arrivals of the Conrad reflections. In order to obtain synthetic seismograms including those later phases, the computational procedure of the reflectivity method was modified. The present result claims that the crustal structure under south-western Honshu, Japan need not have a low-velocity zone above the Conrad discontinuity. But a surface layer of low-velocity sediments should be taken into consideration.