Three-dimensional density spectra of sandy sediments

Power spectra of density variability for sandy sediments offshore Panama City, Florida, estimated and modeled using digital x-ray computed tomography images of sediment structure. Spectral analysis reveals that while shell pieces and mud mixtures are the main contributors to density variability at large scales, intrinsic density variability associated with sand grain contacts dominates at small scales. The power spectrum of sandy sediments is modeled by an analytic form that consists of two power-law components, one associated with the shell and mud contributions and the other with the intrinsic density variability of sand. The dominant term has a much higher power-law exponent than previously reported. implications for the scattering of high-frequency sound in sandy sediments are discussed. (C) 2000 Acoustical Society of America. [S0001-4966(00)00304-0].