Influence of seabed on very low frequency sound recorded during passage of merchant ships on the New England shelf
Abstract
An examination of the received spectrogram levels of about twenty merchant ship recordings on two vertical line arrays deployed on the New England continental shelf during the Seabed Characterization Experiment 2017 has identified an acoustic feature that can be attributed to the group velocities of modes 1 and 2 being equal at a frequency f=F. The observation of such a feature is a result of βnm(2πF)=∞, where βnm is the waveguide invariant for modes n and m. For the New England Mudpatch, the average value of F is about 24.5 Hz. An effective seabed model is inferred from a feature inversion method that has a deep sediment layer which lies between 190 m and 290 m beneath the seafloor with sound speeds on the order of 1810 m/s. This effective sediment model appears to be consistent with a previous seismic survey on the New England shelf that identified a deep low speed layer about 250 m beneath the water sediment interface.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2021
- Source ID
- 10.1121/10.0004991
Entities
People
- David P. Knobles
- Preston S Wilson
- Tracianne B Neilsen
- William Hodgkiss
Organizations
- Brigham Young University
- Office of Naval Research
- University of California
- University of Texas at Austin