Auf Wikipedia gibt es eine Liste von Klängen, deren Quelle bis heute ungeklärt ist.
NOAA
The following unidentified sounds were detected by the USA National Oceanic and Atmospheric Administration using its Equatorial Pacific Ocean autonomous hydrophone array.
Bloop
Julia
Slow Down
Train
Upsweep (‚Upsweep‘ may have been tracked to an undersea South Pacific mountain that was not previously identified as a „live“ volcano,[1] although this is still unconfirmed.[2][3])
Whistle (‚Whistle‘ was only detected by a single autonomous hydrophone from the array.[4])Other
Colossi of Memnon
Bioduck[5]
UVB-76Non-specific
The Hum
Mistpouffers
Unexplained booms
Mit gefallen die Namen, wie „mistpouffers“, „The Bloop“, „The Hum“ oder „Julia“. (Wäre ich ein Mädchen geworden, hätte ich Julia geheißen.)
The NOAA’s Dr. Christopher Fox does not believe its origin is man-made, such as a submarine or bomb, or familiar geological events such as volcanoes or earthquakes. While the audio profile of the Bloop does resemble that of a living creature, the source is a mystery both because it is different from known sounds and because it was several times louder than the loudest recorded animal, the blue whale.
Einen hätte ich auch noch beizusteuern: