Sediment Volume Scattering

Abstract

Sediment heterogeneity can produce appreciable levels of sound scattering, particularly in soft sediments for which transmission into and out of the seafloor is facilitated by the small contrast of sediment density and sound speed compared to water. Heterogeneity, as demonstrated in Ch. 7, can take many forms: layering due to widespread erosional and deposition processes, continuous spatial fluctuations in acoustic properties due to the activity of benthic animals [Jones and Jackson 1997], buried shell fragments [Ivakin 2005, Lyons 2005], gas bubbles [Tang et al. 1994, Boyle and Chotiros 1995a, Lyons et al. 1996], and the inherent granularity of the sediment itself [Williams et al. 1988, Chotiros 2002a, Greenlaw et al. 2004]. It is generally agreed that sediment volume scattering is an important contributor to seafloor reverberation [Ivakin 1981, Ivakin and Lysanov 1981a, Ivakin and Lysanov 1981b, D. Jackson et al. 1986a, Ivakin 1990, Hines 1990, D. Jackson and Briggs 1992, Gensane 1993, Lyons et al. 1994, Pace 1994, Boyle and Chotiros 1995b, Yamamoto 1996, Hines 1996, Pouliquen et al. 2000b, Pouliquen and Lyons 2002].