The Bloop
In the 1960s, the U.S. Navy set up several hydrophones around the globe to track Soviet submarines. The network was known as the Sound Surveillance System. They lie thousands of feet below the ocean surface, at a depth where sound waves become trapped in a layer of water known as the "deep sound channel". Years after the Cold War ended, the U.S. National Oceanic and Atmospheric Administration gave them a new purpose as part of the Acoustic Monitoring Project. They couldn't imagine some of the strange sounds they would record deep underwater. One was recorded in 1997 and is still a mystery to this date. They dubbed it "The Bloop". This sound existed for about a minute, picked up by multiple sensors over an area of 3,000 miles in the south Pacific Ocean west of the southern tip of South America and appeared several times. There have been theories concerning its origins. Some have been ruled out like the possibility of it being man-made, a volcano or earthquake....