The S-wave structures of shallow marine sediments are important for offshore geotechnical studies, deep crustal S-wave imaging, multicomponent seismic exploration, and underwater acoustics studies. We apply multi-component Scholte-wave analysis technique to an active-source shallow marine seismic profile in the East China Sea. Scholte waves were excited by a 5450 inch3 air-gun array shots and recorded at the seafloor using Ocean Bottom Nodes (OBNs). First, we extract the common receiver gathers (CRGs) and correct for the time drift simultaneously using a forward and inverse Fast Fourier Transform resampling algorithm. Three CRGs of seismic sensors were used for Scholte-wave analysis. Raw sensors CRGs were rotated to the inline, crossline and vertical coordinate system. The rotated tilt and roll angle were directed using the inner electric compass log value, and the shot inline azimuth was estimated using the particle motion method. The velocity spectra were then calculated from the inline and vertical components using the phase-shift method. Higher Scholte-wave modes dominated on horizontal components, while the stronger fundamental mode dominated on the vertical component. The multi-component velocity spectrum stacking (MVSS) method was adopted to produce the final dispersion energy image. Up to four modes of dispersion curves were retrieved within the 1.1–4.3 Hz frequency band. Multi-mode dispersion curves inversion was constructed for imaging the shallow sediments. The results suggest low Vs of 180–650 m/s, and little lateral variations within the top 0.5 km of shallow marine sediments in the East China Sea. This model can provide an important reference for offshore geotechnical investigations, especially for OBN multi-component seismic exploration data processing. The use of OBNs shows high feasibility in Vs imaging for shallow-marine sediments when combined with the Scholte-wave dispersion curve inversion.
