oa Crs-Stack Method for Improved Seismic Imaging: A Case Study for Median Tectonic Line

We processed a marine multi-channel seismic (MCS) data acquired across the Median Tectonic Line (MTL) in southwest Japan using CRS-stack method. MTL is an arc-parallel strike-slip fault related to oblique subduction of the Philippine Sea plate beneath the Eurasian plate, and it separates the Ryoke belt from the Sambagawa belt throughout Southwest Japan. Because the subsurface fault geometry of the MTL have not been cleared sufficiently in seismic profiles, the high-quality seismic images are required. A common-reflection-surface (CRS) stack method is a multi-parameter stacking technique which has been proposed as an alternative to the conventional CMP-stack method. The CRS-stack method does not require the macro-velocity model and increases the stacking-fold number. Therefore the CRS-stack method has a potential to enhance reflection signals over the conventional CMP-stack method. Here we applied CRS-stack method to these low-fold seismic data acquired across the MTL and compared the results from conventional CMP-stack method. We show that the CRS-stack method enhanced the reflections signals from faults at depth as well as lithological boundaries.