Spatial distribution of Vp/Vs for sediment and crust off Sanriku, Japan, using distributed acoustic sensing data

Abstract The ratio of P-wave to S-wave velocity (Vp/Vs) is a key indicator of subsurface fluid pressure and rock properties. However, its spatial distribution in offshore regions has been poorly constrained because of difficulties in resolving shallow seismic velocity structures, particularly Vs structures. Recent advances in distributed acoustic sensing (DAS) enable dense seismic observations even on the seafloor, improving imaging of both Vp and Vs. In this study, we estimated the spatial dist