The Ocean is a pretty scary place and over the years many mysterious sounds have been recorded from deep down that to this day have no solid explanation. Here are five of those that are not only creepy and eerie but could also be a glimpse of the incredible undiscovered creatures of the deep sea.
Bloop was an ultra-low-frequency and extremely powerful underwater sound detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) in 1997. The sound is consistent with the noises generated by icequakes in large icebergs, or large icebergs scraping the ocean floor, but is also believed to be consistent with large marine animals.
Upsweep is an unidentified sound detected on the American National Oceanic and Atmospheric Administration’s equatorial autonomous hydrophone arrays. This sound was present when the Pacific Marine Environmental Laboratory began recording its sound surveillance system SOSUS in August, 1991. It consists of a long train of narrow-band upsweeping sounds of several seconds in duration each. The source level is high enough to be recorded throughout the Pacific. The sound appears to be seasonal, generally reaching peaks in spring and autumn.
The Train is the name given to an unidentified sound recorded on March 5, 1997 on the Equatorial Pacific Ocean autonomous hydrophone array. The sound rises to a quasi-steady frequency.
Julia is a sound recorded on March 1, 1999 by the U.S. National Oceanic and Atmospheric Administration (NOAA). The unidentified sound lasted for about 15 seconds. Due to the uncertainty of the arrival azimuth, the point of origin could be between Bransfield Straits and Cape Adare.
Slow Down is a sound recorded on May 19, 1997, in the Equatorial Pacific Ocean by the U.S. National Oceanic and Atmospheric Administration. The name was given because the sound slowly decreases in frequency over about 7 minutes. It was recorded using an autonomous hydrophone array. The sound has been picked up several times each year since 1997.