Measurements of Breaking Wave Noise in the Sea-Cliff Zone

Abstract

This paper presents measurements of the breaking wave noise originated at a sea-cliff zone along the coast of Ando in southern Korea. The breaking noise was recorded using an omni-directional hydrophone deployed at a depth of 3m at a location approximately 80m from the sea-cliff. A spectrogram indicates that the breaking noise persists for a few seconds after a sudden onset with broad-band acoustic energy. The source level per unit area is estimated from the received power-averaged spectral density which was compensated for the acoustic propagation effect from the effective source region to the receiver, predicted using the parabolic equation method. The form of the source level spectrum of the waves breaking against the sea-cliff is similar to that reported in the literature for the plunging breakers in the surf zone. However, the overall source level of the waves breaking against the sea-cliff is 5 to 15 dB higher than that of the plunging breakers. (C) 2010 The Japan Society of Applied Physics