2023_programme: Acoustic propagation characteristics in marine seismic reflection surveys

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  • Session: 06. Marine sediment acoustics
    Organiser(s): Megan Ballard, Kevin Lee and Nick Chotiros
  • Lecture: Acoustic propagation characteristics in marine seismic reflection surveys
    Paper ID: 1964
    Author(s): Douglass Alexander, Abadi Shima, Wood Warren, Phrampus Benjamin
    Presenter: Douglass Alexander
    Abstract: Marine seismic reflection surveys are a type of experiment that generates significant quantities of data over large regions of the ocean, much of which is publicly available. The primary data of interest are acoustic reflections from the seabed on a long (up to ~15 km and 1200 channels) towed hydrophone array. These data are used to image both shallow and deep seabed layers (multiple kilometers below the seafloor). To generate acoustic reflections, complex airgun arrays producing impulsive signals at levels typically exceeding 220 dB are used. The array is typically fired every ~30-50 m, generating tens or hundreds of thousands of shots over a survey. Thus, significant amounts of data are readily available to utilize data science methods to study acoustic propagation and interaction with the seabed. Accurately characterizing the behavior of the airgun arrays and understanding how seabed features impact acoustic propagation are critical to understanding the acoustic fields generated by these surveys. In this work, characterization of the airgun array beam pattern using experimental data is explored and compared with airgun array simulations. An analysis of the array beam pattern and its variability is critical for accurately modeling different acoustic propagation scenarios. Additionally, seabed inversion results are examined and compared with metrics such as Sound Exposure Level (SEL) to determine the effects of different characteristics on these metrics. Prior analysis of these data has shown cases where SELs at ranges of ~10 km (4 times the depth in these cases) exceeded those expected by a simple propagation model by 15 dB. These studies are both critical for fully understanding the acoustic propagation and specifying regulations during these surveys [work supported by ONR].
      Download the full paper
  • Corresponding author: Dr Alexander Douglass
    Affiliation: University of Washington
    Country: United States
    e-mail:

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