Attenuation of Sound in Sea Ice, 10–500 kHz

Abstract

AbstractMeasurements of the attenuation of acoustic waves in sea ice at frequencies f between 10 kHz and 500 kHz have been made on the ice cover at Tanquary Fiord, Ellesmere Island (lat. 81° 25′ N., long 76°50′ W.). A horizontal transmission path at a depth of 4 ft (1.3 m), mid-way between the top and bottom surfaces of the ice cover, was used at ranges varying from 25 ft (7.6 m) to 4 ft (1.3 m) between piezoelectric transducers immersed in oil-filled bore holes. The attenuation coefficient α was found to fit the equation a α = c1f+c2f4 with c1 = 4·45 × 10−2 db m−1 kHz−1, and c2 = 2·18 × 10−10 db m−1 kHz−4. Over the frequency band covered, the linear term was predominant and the Rayleigh scattering term relatively insignificant.