|Filing Number:||186 - List of Unexplained Sounds|
|Lost & Found:|
|Tags:||sounds; audio; underwater; oceans; hydrophones|
From the Wikipedia page List of Unexplained Sounds, a number of recordings taken from underwater hydrophones. While most are suspected to be the sounds of ice sheets calving or scraping the bottom of the ground, they are not confirmed.
Digital archive contains files of the recordings, as well as a PDF print out of the page detailing the time and place of the recordings, and discussing proposed explanations.