2023_programme: Acoustic transmission under Arctic ice model: porous keels

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  • Session: 01. Acoustics in polar environments
    Organiser(s): Jaroslaw Tegowski, Philippe Blondel and Hanne Sagen
  • Lecture: Acoustic transmission under Arctic ice model: porous keels [invited]
    Paper ID: 1862
    Author(s): Chotiros Nicholas
    Presenter: Chotiros Nicholas
    Abstract: Acoustic propagation loss under the Arctic ice sheet is known to be increased when ice is present. The reflection loss from a flat sheet of ice is not enough to explain the loss. The most important cause is believed to be the ice keels. Current models include a ray theory that accounts for the deflection of sound rays by the keels, and alternatively an effective flat interface reflection loss that compensates for the losses due to the presence of the keels. A different model is proposed based on the knowledge that the keels are porous and composed of a loose aggregation of ice blocks. Published measurements of average porosity and block size allow a model to be constructed and studied by a finite element (FE) code. The FE simulations suggest that the keels may be approximated as a poro-acoustic medium, in which the attenuation increases as the square of the frequency. This is also consistent with a simple model based on the extinction cross-section of the ice blocks. [Work supported by ONR, Ocean Acoustics Program]
      Download the full paper
  • Corresponding author: Dr Nicholas Chotiros
    Affiliation: The University of Texas at Austin
    Country: United States
    e-mail:

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