DocumentCode :
3393785
Title :
A Physical Explanation For Less Than Quadratic Recorded Attenuation Values
Author :
Collis, Jon M. ; Carey, William M. ; Pierce, Allan D.
Author_Institution :
Boston Univ., Boston
fYear :
2007
fDate :
18-21 June 2007
Firstpage :
1
Lastpage :
3
Abstract :
A review of experimental evidence shows that the low frequency attenuation of compressional acoustic waves in sandy marine sediments obeys a simple power law consistent with a frequency dependent attenuation proportional to fn , n =1.0. This observation is in general agreement with Biot´s model (1956) for frequencies less than 1 kHz. Recent theoretical work [A. D. Pierce etal., Proc. Oceans 2005, Brest, FR. (2005)] shows that in this lower frequency range, a quadratic dependence (n=2) is to be expected and is decreased by predictable modal propagation characteristics in shallow water. Physical properties and depth-dependent characteristics of the sediment are used to explain the apparent n=18 power law dependence of attenuation. Calculations performed using parabolic equation codes with simplified Biot geoacoustic profiles are compared to experimental results.
Keywords :
acoustic wave absorption; parabolic equations; sediments; underwater acoustic propagation; Biot geoacoustic profiles; attenuation values; compressional acoustic waves; marine sediments; parabolic equations; Acoustic propagation; Acoustic waveguides; Acoustic waves; Attenuation; Frequency dependence; Nonlinear acoustics; Nonlinear equations; Oceans; Sediments; Underwater acoustics; nonlinear attenuation; ocean acoustics; sediment attenuation;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
OCEANS 2007 - Europe
Conference_Location :
Aberdeen
Print_ISBN :
978-1-4244-0635-7
Electronic_ISBN :
978-1-4244-0635-7
Type :
conf
DOI :
10.1109/OCEANSE.2007.4302337
Filename :
4302337
Link To Document :
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