Physical mechanisms underlying the acoustic signature of breaking waves

Authors

  • Cameron Dallas <p class="p1">University of Victoria</p>
  • Cristina Tollefsen Defence Research and Development Canada

Abstract

The characteristic sound of breaking waves is an integral component of the ambient noise along the coastline.  The underwater noise generation from breaking waves has been thoroughly studied, but very little work has been published on the airborne noise caused by breaking waves. Acoustic recordings from a field study were analyzed in an attempt to determine the noise generation mechanisms. A microphone was deployed at Osborne Head, Nova Scotia from June – August 2011 on a grassy cliff above a beach with abundant breaking wave activity. Photographs, weather and ocean wave data were collected to assist in interpreting the audio recordings. Individual breaking wave events were located in the data and their third-octave band spectra were analyzed. The sound pressure levels in the 50 to 315 Hz bands increased by 5 to 20 dB as the wave breaking occurred. The frequency range of the disturbance was used to postulate the breaking wave mechanisms which give rise to its characteristic sound: falling water impacting the surface and the large collapsing air volume present for wave heights greater than 1 m.

Author Biography

Cameron Dallas, <p class="p1">University of Victoria</p>

Department of Physics and Astronomy

Published

2015-08-19

How to Cite

1.
Dallas C, Tollefsen C. Physical mechanisms underlying the acoustic signature of breaking waves. Canadian Acoustics [Internet]. 2015Aug.19 [cited 2021May13];43(3). Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/2779

Issue

Section

Proceedings of the Acoustics Week in Canada