No one knows for sure what made this mysterious undersea noise
In 1997, the National Oceanic and Atmospheric Administration detected a mysterious undersea sound—incredibly loud, and at a very low frequency—and puzzled for years over its origin. Take a listen here. It may sound a little bit like your stomach when you’re hungry, but scientists have theorized that everything from a massive marine animal to a shifting iceberg is responsible. Icebergs cracking and shifting on the ocean floor produce a similar sound, so that’s the most likely explanation, but there’s no definite answer yet as to what it is.
