Effect of spatial distribution of shallow water explosive sources over a muddy seabed on vector acoustic measures

Vector acoustic observations of underwater sound provide several properties of the sound field not accessible in pressure data. The sensor known as Intensity Vector Autonomous Recorder (IVAR) coherently measures pressure and 3-axis acceleration, enabling estimates of both kinetic and potential energy, and other vector acoustic measures involving the coherent combination of acoustic pressure and velocity. IVAR measurements of signals originating from broadband explosive sources (SUS charges) made during the Seabed Characterization Experiment (SBCEX) are analyzed. The SUS deployments made on and around the perimeter of the New England Mud patch (NEMP), a thick depression of mud sediments on the continental shelf roughly 95 km south of Cape Cod, reveal a spatial variation of the energetic and vector acoustic properties. Changes in bathymetry, mud thickness, and sediment layer composition along the source-receiver track are modeled and compared to measured data. The advantage of using these vector properties for geoacoustic inference is discussed.