Research on forward modeling of seismic waves in moving medium and reverse time migration imaging methods

In marine seismic exploration, conventional seismic wavefield simulation methods typically treat seawater as a static homogeneous medium, employing fixed velocity models for forward modeling and reverse time migration (RTM). This approach neglects the actual flow characteristics of the ocean, leading to distortions in seismic wavefield propagation simulations. Particularly during reverse time migration, errors in the wavefield's back-propagation path accumulate progressively, ultimately compromising the accuracy and reliability of seafloor structure imaging. To address this issue, this study investigates the seismic wave propagation mechanism in moving medium based on hydrodynamic theory. It derives an acoustic wave equation tailored to dynamic seawater environments and establishes a more physically realistic wavefield simulation method. Numerical simulations demonstrate that seawater flow significantly alters seismic wave propagation characteristics: wave velocity increases in the downstream direction and decreases upstream—an asymmetric propagation effect unaccounted for in traditional static models. The proposed dynamic simulation method effectively captures the modulation of wavefields by seawater motion, enabling accurate reconstruction of true seafloor structures through precise RTM. This approach markedly improves seismic imaging accuracy in complex marine.