Deep crustal imaging by wide-angle seismic data using seismic interferometry and prestack depth migration.

摘要

Pre-stack depth migration (PSDM) of wide-angle seismic reflection and refraction survey data has a potential to image deep reflectors because the amplitude from a deep reflector becomes large at large offset. However, PSDM of wide-angle data has rarely been applied to the actual data because practical wide-angle surveys are usually too sparse to apply the PSDM. Seismic Interferometry (SI) can dramatically change the situation. By applying the SI to the wide-angle (OBS-airgun) data set, pseudo and dense receiver gathers can be generated. In this study, we generated pseudo receiver gathers by applying SI to the actual OBS-airgun data obtained in the North-Western Pacific region, and we tried to image oceanic Moho, which was about 12 km below the sea surface, by applying PSDM. We conducted a large number of parameter tests, and succeeded in imaging the oceanic Moho.