Impacts of seafloor characteristics on sound propagation in a seamount environment Free

The New England Seamounts are located off the coast of Cape Cod. The Atlantis II Seamount, 400 miles southeast of Woods Hole, was the site of the recent New England Seamount Acoustics (NESMA) experiment during April–June of 2023. This seamount and others nearby contain complicated bathymetry with the Atlantis II peak rising roughly 3300 m from the seabed and 1700 m below the sea surface. During the experiment, broadband SUS charges were deployed in a 15 km radius around the seamount. A set of three bottom-mounted vector sensors recorded acoustic pressure and particle velocities. Data from an AUV-mounted sub-bottom profiler provided information about the sediment layers, including a sand layer atop limestone, overlying basalt. Using the RAM parabolic equation model, broadband arrivals were simulated. In addition, the Bellhop raytracing model was used to identify the arrivals. The measured data was compared to the synthetic time series produced by the models to understand the effects of the complex environment on acoustic propagation in the vicinity of the Atlantis II Seamount. [Work supported by Office of Naval Research Code 322OA and TFO.]