A Method for Velocity Inversion of Deep-Sea Water Body Using Wave Equation Traveltime

Abstract

In marine seismic data processing, velocity errors in deep-sea water can lead to distortions in seabed positioning, which in turn cause deformations in deeper geological strata. The existing methods suffer from sparse data, limited applicability, and an inability to invert for the deep-sea sound channel structures. Therefore, we propose a method employing wave equation traveltime inversion (WTI) for the velocity of deep-sea water body. When traditional ray-based traveltime methods are used in complex seabed topographies, seismic wave propagation paths become extraordinarily intricate, rendering ray tracing and traveltime picking imprecise. Conversely, the WTI does not require ray path tracking nor seabed reflection traveltime picking, enabling more accurate simulation of wavefront diffusion in complex structures. Through experiments conducted on theoretical models and actual data, it has been verified that the WTI method can provide more accurate inversion results in complex seabed topography, reliably depicting the velocity structure of deep-sea water body even when the initial velocity model is far from the true seawater velocity.