Abstract

Seismic velocity inversion of upper crustal structures in deep sea is challenging, as the unique condition of thick water column often limits the applicability of conventional inversion techniques. For example, while dispersion curves of guided P waves are commonly utilized for estimating subsurface P-wave velocity in land and shallow water environments, these waves have remained in obscurity in deep-water environments due to interference from subseafloor reflections, making them difficult to observe and, until now, unobserved. In this work, we report the first observation of guided P waves in deep water from multichannel seismic data and successfully extract multimode dispersion curves. The dispersive modes of deep water guided P waves are controlled by layered medium beneath the seafloor. Analyzing the dispersive modes of deep water guided P waves provides a tool for subsurface structural inversion in deep water environments.