Seismic Imaging of Receiver Functions at Virtual Receivers in Ryukyu Arc, Japan

This study describes the seismic images of the crust and uppermost mantle beneath the Ryukyu Arc, Japan by using S-wavevector receiver functions (SWV-RFs) analysis at virtual subsurface receivers. The SWV-RFs are the time series deconvolving the upgoing SV-wave component by the upgoing P-wave one. This method for ground surface records was originally introduced by Reading et al. (2003, GRL). Takenaka and Murakoshi (2010, AGU) proposed the SWV-RFs at the surface or subsurface station, which virtually move the seismic sensor at the surface or in the borehole down to the top of the basement layer and calculate the SWV-RFs at that location for suppressing the sedimentary layer effect. The SWV-RFs have a great advantage that the problem of unclearly seismic images beneath very thick sedimentary basin due to the records include strong effect of reverberation within the sedimentary layer can be overcome. Takenaka et al. (2014, AGU) applied the SWV-RFs to the teleseismic waveform records observed at borehole and ground surface stations and obtained clearly seismic images of Moho and subducted Philippine Sea plate beneath in Kyushu island, Japan. In this study, we applied the SWV-RFs from broadband seismic records of the F-net (NIED) and ETOS (JMA) to obtain the seismic structures in Ryukyu Arc, Japan. In this presentation, we will show the estimated seismic structure under each stations in the Ryukyu Arc, Japan. Acknowledgement: We have used Fnet data (NIED), ETOS data (JMA) and deep subsurface structure model by J-SHIS (NIED).