How much does sound velocity change for every 100 feet of depth?

The change in sound velocity with depth is a fundamental concept in oceanography and acoustics. The correct answer indicates that for every 100 feet of depth, the sound velocity changes by 1-7 feet per second (fps). This range is based on empirical observations and formulas commonly used in underwater acoustics, such as the empirical relationship defined in the Mackenzie equation.

At various depths in the ocean, temperature, salinity, and pressure all contribute to the sound speed profile. With increasing depth, pressure increases significantly, which tends to increase the sound velocity. However, temperature can also play a critical role, particularly in shallower depths where temperature changes can be more pronounced. The combination of these factors results in a sound velocity increase that typically falls within the range given in the correct answer.

Understanding the range of sound velocity changes with depth is critical for numerous applications in naval operations, marine research, and underwater communication systems, allowing for accurate sonar readings and effective navigation in underwater environments.