ABSTRACT
Acoustical oceanography includes both the study of acoustics in the ocean and the use of acoustics to study the ocean. Acoustical oceanography crosses four other branches of oceanography: physical, chemical, geological, and biological oceanography. Sound propagation is profoundly affected by the conditions of the surface and bottom boundaries of the ocean as well as by the variation of sound speed within the ocean volume. Knowledge of the state of the sea surface as well as the composition and topography of the sea floor is important for specification of boundary conditions. The depth dependence of sound speed in the ocean poses a particular problem for echo sounders, which use near-vertical acoustic paths to measure the depth of the sea floor based on the two-way travel time of the signal. The degree of abruptness in the change of water-mass characteristics determines whether the front is classified as a strong or weak front.
