How does sound travel relatively long distances underwater?
Sound travels approximately 1500 meters per second in seawater. That’s a little more than 15 football fields end-to-end in one second! Sound travels much more slowly in air, at approximately 340 meters per second, only 3 football fields a second. The speed of sound in seawater is not a constant value, and although the variations in the speed of sound are not large, they have important effects on how sound travels in the ocean. A sound channel exists in the ocean that allows low-frequency sound to travel great distances. This channel is called the SOund Fixing And Ranging, or SOFAR, channel. Sound bends or refracts towards the region of slower sound speed, creating this sound channel in which sound waves can travel long distances. In the spring of 1944, ocean scientists, Maurice Ewing and Joe Worzel, departed Woods Hole, Massachusetts, aboard the research vessel R/V Saluda to test a theory that predicted that low-frequency sound should be able to travel long distances in the deep ocean.
