Applied Underwater Acoustics

Chapter 1

General Characteristics of the Underwater Environment

L. Bjørnø^1,†, and M.J. Buckingham^2     1UltraTech Holding, Taastrup, Denmark     ²Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States

Abstract

This chapter provides a framework and roadmap for the book. It starts with a brief history of underwater acoustics from the time of the Greek philosopher Aristotle (384–322 BC) up to the post–World War II era. This is followed by a discussion of the international system of units used in the book and a discussion on the use of the decibel scale. Next, the chapter deals with the features of oceanography including sound speed profiles, thermoclines, arctic regions, deep isothermal layers, expressions ...