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.
The sound, traced to somewhere around 50° S 100° W (South American southwest coast), was detected repeatedly by the Equatorial Pacific Ocean autonomous hydrophone array, which uses U.S. Navy equipment originally designed to detect Soviet submarines. According to the NOAA description, it "rises rapidly in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over 5,000 km." 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.
So, the bloop (50°S 100°W / -50, -100) is near Point Nemo, an oceanic pole of inaccessibility (48°50′S 123°20′W / -48.833, -123.333).
In popular culture
Because the Bloop noise originated near the location of the fictional sunken city of R'lyeh from H.P. Lovecraft's story "The Call of Cthulhu", the Bloop has been linked to Cthulhu by Lovecraft fans. In the alternate reality game promoting the movie, the Bloop was also linked to the monster from Cloverfield The Bloop was seen in The Loch by Steve Alten as the call of an undiscovered species of giant eel, as well as in Frank Schätzing's novel The Swarm as the speech of the intelligent species, the Yrr.. The title track from Dntel's 2001 album Life Is Full of Possibilities repeats a sample of the Bloop sound set to music.