Seabed property estimation from ambient-noise recordings: Part I — Compliance and Scholte wave phase-velocity measurements

The ability to derive a near-surface shear-velocity profile from ambient-noise records is useful for seismic applications such as shear-wave statics estimation and geohazard prediction. Measurements of seafloor compliance and Scholte wave velocity and amplitude are all related to the near-surface shear-velocity profile. I analyzed a data set of 33minutes of continuous noise records recorded by an ocean bottom cable deployed in 273-m deep water for seafloor compliance and Scholte waves. I failed to observe seafloor compliance because of limitations in the record length. I have detected Scholte waves on the inline and vertical component geophones and Love waves on the crossline component using f-k spectra. Both the Scholte and Love wave phase-velocities can be explained by a simple 1D isotropic near-surface model. The Scholte waves may have been excited by acoustic energy from the recording vessel, while no satisfactory excitation mechanism has been found for the Love waves.