Estimation of shear wave speed at the New England Mud Patch using vector sensor measurements

Horizontal to vertical spectral ratio (HVSR) of the Scholte wave particle motion can be used to estimate ocean bottom shear properties. This study uses data from two ocean bottom recorders (OBX) deployed during the Seabed Characterization Experiment (SBCEX 2022) in the New England Mud Patch (NEMP). Sediment thickness data from seismic surveys and core data were used to constrain the shear speed estimation approach. The bottom model estimated by matching the HVSR and ellipticity angle from a model with the data compares well with two previous inversions from the same location. The current inversion estimates shear speed in the sublayers within the mud layer which were identified by the seismic surveys and core data. The HVSR based method is a fast and robust inversion approach for estimating the thickness of the sediment layers and the shear wave speeds. The data used for this study consist primarily of ambient seismic field mixed with potential far field anthropogenic noise sources (e.g., ships, sources deployed as part of experiment). [Work supported by the Office of Naval Research, code 322 OA.]