From Wikipedia:
Bloop or The Bloop is a mysterious ultra-low and extremely powerful underwater frequency detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) in 1997. The source of the
sound remains unknown.
The
sound, traced to somewhere around 50° S
100° W (a remote point in the south Pacific Ocean
west of the southern tip of South
America), was detected several times by the Equatorial Pacific Ocean autonomous hydrophone array. This system was developed as an autonomous array of hydrophones that could be deployed in any oceanographic region to monitor specific phenomena. It is primarily used to monitor undersea seismicity,
ice noise, and marine mammal population and migration. This is a stand alone system designed and built by NOAA's Pacific Marine Environmental Laboratory (PMEL) to augment the U.S.
Navy SOund SUrveillance System (SOSUS), equipment originally designed to detect Soviet submarines.
TL;
DR: The Bloop is a shit-pants
sound coming from the bottom of the fucking ocean. The
sound went across the entire South Pacific and was picked up by underwater recorders placed pretty much all around the ocean. To make matters even creepier, it is louder than any underwater creature ever recorded. Multiple sounds were recorded around the same year which were dubbed Whistle,
Train, Slow Down, Julia, and Upsweep.
And yet another thing that makes Bloop even fucking scarier is the fact that the sounds were at a
special frequency that shows that these were in-fact made by living things at the very bottom of the ocean. And in the H.P. Lovecraft (the guy that wrote about things like Shoggoth, Cthuluhu, and others)
books, it states that the place where Cthuluhu sleeps is located almost exactly where The Bloop was traced. What the unholy fuck. Not to mention Lovecraft died
60 years before these sounds were ever recorded.
I played The Bloop when my cat was in the room and my cat went fucking apeshit. I'm not kidding.