New acotistic seabed profiling systems have been introduced in the past 15 yeas that represent a quantum leap in our abilitY to, characterize the seafloor for geotechnical and other scientific purposes. However, the data from such systems is not entirely useful in and by itself. It needs to be combined with ground truth measurements obtained from conventional geotechnical tests conducted either in the field or on samples collected from borings or various coring devices. Correlations between acoustic and physical properties are presented to contribute to the continuing effort to develop improved acoustic systems for the remote identification and measurement of marine sediments.
The basic coupled hydraulic-mechanic behavior of poroelastic materials, such as marine sediments, was developed by Biot in the late 1930s and early 1940s (Biot, 1941). Acoustic wave propagation through such materials was also considered by Biot (1956a, 1956b, 1962a, 1962b), who showed that there exists a fundamental link between the physical properties of a poro-elastic material (compressibility, porosity and geometry of the pores, grain size) and the acoustic characteristics of propagating waves (wave velocity and attenuation). Much work has followed since trying to expand the Blot theory to account for a wider range of material types, energy dissipation processes, and wave types (see for example Stoll, 1989). The development of powerful new acoustic instrumentation for marine applications, particularly in the last 30 years, has been driven in part by an interest in making use of the link that exists between sediment physical and acoustic properties for remote identification and measurement of seabed sediments. Central to this effort has been a need to establish relationships between sediment acoustic and physical properties from either laboratory or field tests.
