Geoacoustic Inversions in the New England Mud Patch

Seabed Characterization Experiment (SBCEX) was conducted in New England Mudpatch south of Martha’s Vineyard in 2017. The water depth at the location is approximately 70 m. The ocean bottom consists of a thin layer of mud over sand layers. Data collected on geophone and hydrophone arrays will be presented. The properties of the bottom are estimated using geoacoustic inverse methods. Localization of the hydrophone array indicated that the individual geophones in the array were buried in the mud layer at different depths. Acoustic normal mode dispersion characteristics of hydrophone and geophone data show interesting differences that will be explored and exploited in this study. Possible causes such as shear resonance in the mud layer and interface wave generation along the mud-sand interface are explored to explain the hydrophone-geophone data differences. Modeling to match the data is carried out with appropriate sediment parameters. The estimated sediment parameters are compared with core data and other inversions. [Work supported by the Office of Naval Research]