This was recorded by the scientists there.
https://www.youtube.com/watch?v=HxOHV65DpSs
Weather balloon
Swamp gas
>>18454194
Mating whales.
sounds more like a sonar than a whale
>>18454194
Its a baleen whale call
http://www.sciencealert.com/scientists-have-identified-that-mysterious-metallic-sound-coming-from-the-mariana-trench
>>18454194
Cthulhu bass drop. He got Skrillex hair.