SOFAR channel
（重定向自Deep sound channel）
![Sound speed as a function of depth at a position north of Hawaii in the Pacific Ocean derived from the 2005 World Ocean Atlas. The SOFAR channel axis is at ca. 750-m depth](/Images/godic/202501/08/Underwater_speed_of_sound.svg5130.png")
![Acoustic pulses travel great distances in the ocean because they are trapped in an acoustic](/Images/godic/202501/08/Rays_test5130.gif")
![](/Images/godic/202501/08/Akhumps_128_016_0_500c5130.png")
The SOFAR channel (short for Sound Fixing and Ranging channel), or deep sound channel (DSC), is a horizontal layer of water in the ocean at which depth the speed of sound is at its minimum. The SOFAR channel acts as a waveguide for sound, and low frequency sound waves within the channel may travel thousands of miles before dissipating. This phenomenon is an important factor in submarine warfare. The deep sound channel was discovered and described independently by Dr. Maurice Ewing and Leonid Brekhovskikh in the 1940s.