Statistical analysis of acoustic propagation in beaked whale habitats.

Abstract

Research and regulatory communities have raised questions about the influence of oceanographic conditions on propagation of midfrequency sound produced by naval sonars prior to beaked whale mass stranding events. Resolving these questions requires detailed study of acoustic properties at locations known to support beaked whale populations potentially at risk of exposure. To address these concerns, this study investigated sound propagation at two known beaked whale habitats: the North Atlantic Frontier to the west of Scotland and Sagami Gulf in eastern Japan, by computing the range dependent propagation loss for an omnidirectional 3.5 kHz signal with a source level of 235 dB re 1 μPa at 1 m. From this, a method was developed to reduce the three‐dimensional sound field to yield a source‐receiver range at which there was a high probability that a given received sound pressure level would not be exceeded. To investigate the uncertainty in data for sound speed profiles and seabed acoustic properties, the sensi...