How does a change of 1/1000 ppt in salinity affect sound velocity?

A change of 1/1000 parts per thousand (ppt) in salinity can significantly influence the velocity of sound in seawater due to the increase in density and the reduction in sound attenuation that occurs with varying salinity levels. The velocity of sound in seawater is affected by several physical properties, including temperature, pressure, and salinity.

Research indicates that a change in salinity has a measurable effect on sound speed; typically, an increase in salinity can lead to an increase in sound velocity. Specifically, it has been observed that for every 1/1000 ppt increase in salinity, the sound velocity can increase in the range of approximately 3 to 5 feet per second (fps). This range reflects the complex interactions within seawater as salinity affects both density and the bulk modulus of the water, which are essential in determining how sound propagates through it.

This knowledge is particularly important for applications in oceanography and underwater acoustics, where precise measurements and predictions of sound speed can impact sonar readings, marine life studies, and navigation systems. Therefore, the correct selection indicates a well-understood relationship between salinity changes and sound velocity alterations in marine environments.