BL00P

The Bloop is the name given to an ultra-low frequency underwater sound detected by the U.S. National Oceanic and Atmospheric Administration several times during the summer of 1997. The source of the sound remains unknown.Though it matches the audio profile of a living creature, there is no known animal that could have produced the sound. If it is an animal, it would have to be, reportedly, much larger than even a Blue Whale, according to scientists who have studied the phenomenon.Info Source : http://en.wikipedia.org/wiki/Bloop