Estimation of compressional and shear wave attenuation at the New England Mud Patch using vector sensor measurements

Compressional and shear wave attenuation were estimated using acoustic pressure and particle velocity data in this study. Broadband signals measured on multiple ocean bottom recorders (OBX) deployed on the seabed during the Seabed Characterization Experiment (SBCEX 2022) in the New England Mud Patch (NEMP) were the inputs to the inversion. Shear conversion effects were accounted for in the attenuation inversion approach. Different inversion schemes based on modal amplitudes and vector properties were implemented to estimate the depth-dependent attenuation profile. The sediment thickness data from seismic surveys and core data were used to provide bottom layering information. The bottom model estimated by previous inversions using data from the SBCEX experiment provided compressional and shear wave speeds in the bottom layers. The attenuation estimates were compared with predictions from Viscous Grain Shearing (VGS) and the modified, corrected, Revil, extended Biot (mCREB) model and other attenuation estimates from the experimental location. [Work supported by the Office of Naval Research, code 322 OA.]