2023_programme: Geoacoustic profiles and dispersion for muddy sediments from inversion of wide-angle reflection data on the New England Mud Patch

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  • Session: 04. Inverse Problems in Acoustical Oceanography
    Organiser(s): Julien Bonnel and Stan Dosso
  • Lecture: Geoacoustic profiles and dispersion for muddy sediments from inversion of wide-angle reflection data on the New England Mud Patch
    Paper ID: 1913
    Author(s): Jiang Yong-Min, Holland Charles, Dosso Stan, Dettmer Jan
    Presenter: Jiang Yong-Min
    Abstract: Wide-angle seabed reflection coefficients as a function of grazing angle and frequency were measured on the New England Mud Patch during the 2017 Seabed Characterization Experiment to explore the spatial, depth, and frequency dependencies of muddy sediment properties. In this work, trans-dimensional Bayesian inversion is applied to the high-signal-to-noise reflection coefficients within a frequency band of 1–3 kHz and angular range of ~15–25° to obtain sub-bottom geoacoustic profiles and associated uncertainties, as well as frequency dependencies of sound speed and attenuation at selected depths. A positive gradient of ~6 m-1 for sound speed is observed in the upper 4 m of the sediments in the inversion results, followed by an approximately homogenous layer to a depth of ~10 m. Below this is an apparent “transition” layer with relatively large positive gradients in sound speed and density, which has been observed in previous inversion results using different acoustic data at different frequency bands, and is interpreted to represent a transition from mud to sand. The attenuation profile is well estimated, providing the clearest indication to date of a steep increase in attenuation in the mud-sand transition layer. It is also observed that the sound speed dispersion is weak and the frequency dependence of attenuation is near to the first power of frequency in the mud layer within the frequency band considered (Work supported by the Office of Naval Research).
  • Corresponding author: Dr Yong-Min Jiang
    Affiliation: SEOS University of Victoria
    Country: Canada
    e-mail:

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