Upsweep is an unidentified mysterious sound detected on the American NOAA’s equatorial autonomous hydrophone arrays. This sound was present when the Pacific Marine Environmental Lab began recording it’s sound surveillance system SOSUS in 1991. Consists of a long train of narrow-band upsweeping sounds of several seconds. The source level is high enough to be recorded throughout the Pacific Ocean.
This puzzling sound, dubbed the Whistle was picked up by one NOAA hydrophone in 1997. The source of this sound is somewhere in the Pacific Ocean. The Whistle is similar to the volcanogenic sounds previously recorded in the Mariana volcanic arc of the Pacific Ocean.
Bloop is an ultra-low-frequency & extremely powerful under-water sound detected by the U.S. National Oceanic & Atmospheric Administration (NOAA) in 1997. The sound is consistent with the noises generated by icequakes in large icebergs. The source was triangulated to a remote point in the south Pacific Ocean.
Julia is an inexplicable sound recorded in 1999 by the U.S. National Oceanic & Atmospheric Administration (NOAA). The source of the sound was most likely a large iceberg that had run aground off Antarctica. Loud enough to be heard over a duration of 2 minutes & 43 seconds.
Slow Down is an unknown sound recorded in 1997 in the Equatorial Pacific Ocean by the U.S. National Oceanic & Atmospheric Administration (NOAA). The source of the sound was most likely a large iceberg as it became grounded.
Train was an unusual sound recorded in 1997 on the Equatorial Pacific Ocean autonomous hydrophone array. The sound rises to a quasi-steady frequency. Origin of the sound is most likely generated by a large iceberg grounded in the Ross Sea near Cape Adare.
So much about our world of sounds still remains unexplained. Unfathomable.