High frequency acoustic waves underwater

[rusty009]

Hi,

was just wondering if anyone could help me out with this query, I'm just curious to know why high frequency acoustic waves are greatly absorbed underwater? Thanks in advance.

 

[WarVsFutility]

I'm assuming you are mentioning sound of higher frequency than 1 Khz. Almost all water in nature has small particles or bubbles in it, and sound travels through those particles at different velocities than the water around it. When sound with such short wavelengths travel through those particles, it becomes slightly out of phase with the surrounding wave, partially cancelling it out. Do this many times, and the wave is greatly reduced. Longer wavelengths are not affected as much, since they are not as close to the particle/bubble/impurity sizes one finds in water. There are also factors such as heat, currents, depth, and chemistry. I hope your question was answered.