A computer model for sound propagation around conical seamounts

This paper demonstrates a technique for computing the long-range sound pressure field around a penetrable conical seamount. The pressure field is generated by a harmonic point source. The seamount is positioned in a vertically stratified ocean. It is modeled as an outgrowth of the sediment layer covering the ocean bottom. First, the seamount is decomposed into superposed rings of diameters increasing with the depth. Thus the problem reduces to a cylindrically layered system. Then, the method of normal modes is used to compute the sound pressure field in each layer. In order to maintain numerical stability, the Direct Global Matrix approach is used. The radial eigenfunctions are expressed as functions of normalized Hankel and Bessel functions, and the linear system that arise is organized in an unconditionally stable matrix. The results show a perturbation zone behind the seamount. It is bounded by two lines going from the source and tangent to the ring that is at the depth of the source. The values of the sound pressure inside the perturbation zone can be higher or lower than the values outside of it, according to the dimensions of the seamount.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Ocean Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Eskenazi, Jérémie, 1976-

Advisor dc:contributor.advisor

• Arthur B. Baggeroer.

• Ocean Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8778

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8778