Inverting for the properties of an elastic seafloor using complex‐density equivalent fluids.

Abstract

Receptions were recorded from a bottom‐mounted broadband source (with a center frequency of 75 Hz) located near Kauai as part of the basin acoustic seamount scattering experiment (BASSEX). Travel times for arrivals from this source have been modeled at basin‐scale ranges using complex‐density equivalent fluids for the elastic seafloor material. The collection of acoustic data at shorter ranges as part of BASSEX allows for a more detailed examination of the accuracy attainable by an equivalent‐fluid representation of the seafloor. The use of equivalent fluids is intended to depict the conversion of acoustic energy into shear waves. The performance and stability of propagation models can be substantially improved if equivalent fluids can be used to accurately characterize bottom interaction. Simulations have been performed in order to search for the equivalent fluid that best explains received data at a range of a few kilometers. The reflection coefficient of this equivalent fluid can then be matched to par...