2025_programme: Seabed characterization using ambient sound inversion for data on the New England Shelf

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  • Day: June 16, Monday
      Location / Time: B. ERATO at 14:30-14:50
  • Last minutes changes: -
  • Session: 07. Inverse Problems in Acoustical Oceanography
    Organiser(s): Julien Bonnel, Stan Dosso
    Chairperson(s): Julien Bonnel, Stan Dosso
  • Lecture: Seabed characterization using ambient sound inversion for data on the New England Shelf [Invited]
    Paper ID: 2364
    Author(s): Martin Siderius, Stan Dosso
    Presenter: Martin Siderius
    Abstract: Wind-driven ambient sound data were analyzed to characterize seabed properties along two tracks on the New England shelf. One study area, known as the New England Mud Patch, is a well-documented region with relatively shallow water (~70 meters) and a mud-over-sand sediment composition. Due to its extensive prior study, this site allows for direct comparison with results from other techniques. The second study area, located closer to the shelf break in approximately 400 meters of water, has been explored to a much lesser extent.\n\nIn both locations, a 15-meter vertical array equipped with 16 hydrophones recorded ambient sound across the 50–5000 Hz frequency range. The array drifted slowly which allowed for estimates to be made at different locations along the tracks. Beamforming techniques were applied to characterize the seabed, focusing on the 400–700 Hz band. Passive fathometer processing was used to estimate both the water-seafloor interface and the underlying sediment layers. Additionally, the power reflection coefficient was derived from the data and utilized in a trans-dimensional Bayesian geoacoustic inversion.\n\nThe findings in the Mud Patch were highly consistent with previous studies, particularly in the characterization of the mud layer and the deeper sediment structure. Results also revealed slight range-dependent variations along the track, evident in the layering structure. Despite some variability, estimates of key seabed parameters—sound speed, density, and attenuation—remained largely stable, with only minor deviations.
  • Corresponding author: Prof Martin Siderius
    Affiliation: Portland State University
    Country: United States

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