Have you heard Bloop? How about Julia? Or Slowdown, Whistle or Upsweep? And who could forget Train?

These aren't nicknames of people on your new kickball team, these are the names given to a series of low-frequency sounds that have been picked up by deep-sea microphones. The sounds have been sped up 10 times. They're all downright spooky.

These microphones are placed in deep, deep locations in the ocean. These sounds were first picked up by military posts listening for enemy subs. Scientists think the sounds are too big for whales to make, and they don't match any known whale recordings. Whatever is making them is HUGE — an animal would have to be enormous to be able to make such a powerful sound at those depths.

Considering how little we actually know about the deep seas (and lakes), it's conceivable that there could be some very large monsters swimming down there. I hope they don't take offense to being tagged "Julia".

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