Attenuation of Sound in Sea Ice, 10–500 kHz

Abstract

AbstractMeasurements of the attenuation of acoustic waves in sea ice at frequenciesfbetween 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 coefficientαwas found to fit the equation aα=c1f+c2f4withc1= 4·45 × 10−2db m−1kHz−1, andc2= 2·18 × 10−10db m−1kHz−4. Over the frequency band covered, the linear term was predominant and the Rayleigh scattering term relatively insignificant.