Three-dimensional density spectra of sandy sediments

Power spectra of density variability for sandy sediments offshore Panama Ci ty, Florida, estimated and modeled using digital x-ray computed tomography images of sediment structure. Spectral analysis reveals that while shell pi eces and mud mixtures are the main contributors to density variability at l arge scales, intrinsic density variability associated with sand grain conta cts dominates at small scales. The power spectrum of sandy sediments is mod eled by an analytic form that consists of two power-law components, one ass ociated with the shell and mud contributions and the other with the intrins ic density variability of sand. The dominant term has a much higher power-l aw exponent than previously reported. implications for the scattering of hi gh-frequency sound in sandy sediments are discussed. (C) 2000 Acoustical So ciety of America. [S0001-4966(00)00304-0].