Nicholas P. Chotiros
Appl. Res. Labs., University of Texas at Austin, P.O. Box 8029, Austin, TX 78713-8029
Age Kristensen
Enzo Michelozzi
SACLANT Undersea Res. Ctr., 19026 LaSpezia, Italy
An experiment was conducted to investigate acoustic penetration of a sandy shallow water sediment, in the band 500 Hz to 2 kHz, in a site off LaSpezia, Italy. Acoustic sensors were buried in the sediment, forming a sparse three-dimensional array, to measure the sediment penetrating signals. The sound source was a sparker. The collected signals are processed coherently to give direction and speed of the sediment acoustic waves. From a theoretical point of view, the medium is treated as a poro-elastic solid governed by Biot's theory of acoustic propagation. It is predicted to support two acoustic waves. Comparisons are made between theory and experiment. [Work supported by Office of Naval Research, Ocean Acoustics Program, Code 11250A, under the initiative for basic research in the physics of moderate to high frequency acoustics.]