Spectral analysis is a technique that uses both the incident and reflected acoustic signals of a low-frequency subbottom profiling system. The differences in spectral quality are converted into time-frequency-energy plots which can be contoured within the dynamic range of 42 db.

Analysis of the resulting energy contour map shows that certain "topographic highs" appear to be related to certain sediment types existing under differing degrees of in-situ moisture content and bulk (wet) densities. The resulting energy contours define these conditions and identify the stratal characteristics as if they were "sedimentary fingerprints."

Data presently available from known areas of Fishers Island and Long Island Sound off the coast of southeastern Connecticut, and the Gulf of Mexico, show good correlation between the spectral energies and the sediment bulk properties to maximum depths of 200 ft.

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