But if you read io9's fantastic piece on the deep sea's mysterious sounds, you'll learn about The Bloop, an unexplained deep-sea noise from 1997. What could have made it?
[One] possibility is some sort of massive squid. These creatures do serve as a catch-all for all that's still mysterious about the ocean depths, and our extremely limited firsthand knowledge of them makes it easier to believe a gigantic Blooping squid could maybe be hiding deep in the Pacific. There's a couple problems with this though.To learn about those problems, and the favored fantastical explanation for the Bloop, read the rest of the article!