[SSS11-P13] On the estimation of G discontinuity in the oceanic upper mantle using ScS reverberations
Keywords:ScS reverberations, G discontinuity, lithosphere-asthenosphere system, northwest Pacific
The method used by previous work (Revenaugh & Jordan, 1991) employs two-step analysis: 0th order analysis for whole mantle parameters and 1st order analysis for the characteristics of mantle discontinuities. Since this method was introduced to investigate the land area of the western circum-Pacific, there has been no detailed verification if it is compatible for the oceanic area whose upper mantle structure significantly differs from that of the continental area. We applied a simplified analysis method to full wave synthetic waveforms generated for an oceanic model with G, and revealed that the conventional method might fail in estimating the upper mantle structure and the whole mantle quality factor Q because of a strong reflected wave from G.
We will attempt to improve ScS reverberation analysis method and to compare its result for the northwest Pacific area with the existing model.