SEGJ Technical Conference

Seismic reflection survey using natural seismic body wave - Retrieval of plate boundary reflection from core phase -

Abstract We used seismic interferometry (autocorrelation analysis) to retrieve the reflected waves at the PHS plate boundary from natural seismic body waves recorded at Hi-net and F-net stations in the Chugoku and Shikoku regions, Japan. We used the PKIKP phase that is regarded as a plane P-wave with near-vertical incident angles as a seismic signal. In the reflection depth profile, laterally-continuous, dipping phases with positive and negative amplitudes were recognized. We interpreted these as the reflection at the oceanic Moho and the PHS plate boundary, respectively. The amplitude distribution of the reflections showed a dependence on depth and region.