High-fidelity numerical simulation of ocean-bottom node 4C seismic data using the acoustic-elastic coupling equation

The complex wavefields in ocean-bottom node (OBN) four-component (4C) seismic data, particularly interface waves like Scholte waves, pose significant challenges for processing and inversion. A key issue is how to achieve high-fidelity and accurate simulation of seismic wave propagation phenomena at the ocean bottom, thereby providing a theoretical foundation for fully leveraging ocean-bottom 4C data in imaging and inversion. To address this, we employ a three-dimensional acoustic-elastic coupling equation (AECE) for high-fidelity numerical simulation of OBN 4C data. This method inherently satisfies the fluid-solid interface conditions without manual enforcement, enabling physically consistent generation of all wave types, including Scholte waves. Numerical examples and field data from the East China Sea demonstrate that the AECE effectively replicates the waveform components and characteristics of field 4C data. This establishes the AECE as a robust foundation for OBN 4C data processing, elastic imaging, and full-waveform inversion.