7 Most Bizarre Underwater Discoveries Nobody Can Explain
2. The Mysterious 'Julia' Sound
In 1999, a spooky sound was picked up by National Oceanic and Atmospheric Administration (NOAA) recording equipment in the depths of the Pacific Ocean.
The eerie noise, which lasted for around 15 seconds and has been christened 'Julia', sounds like somebody cooing or whining. It's the kind of thing that sends imaginations running wild when you consider only around 5% of the oceans have been explored.
An unequivocal explanation for the noise has never presented itself, but the best NOAA researchers could come up with is that it's the sound of an Antarctic iceberg running into the seafloor, which isn't quite as exciting as a deep-sea leviathan.