One of the coolest things about this life is that, no matter how much we learn or how much we know, there is always something new waiting to surprise us.

Like, for instance, a mysterious sound emanating from a spot that we thought was basically empty. Most experts agree that Point Nemo, in the southern Pacific Ocean, is the most remote location on the planet. It’s 1,671 miles from the nearest solid ground – a lot further, even, than it is from humans passing overhead in the International Space Station (250 miles).

The area is, in fact, a graveyard for old spacecraft, like retired satellites and the Russian space station Mir. And in 1997, the U.S. National Oceanic and Atmospheric Administration (NOAA) detected a strange, ultra-low-frequency sound in their hydrophones. The sound was powerful and one of the loudest ever sounds recorded underwater. The “bloop,” as it became known at the NOAA, was a mystery that oceanographers speculated on for some time.

One of those theories was that it could have been caused by a marine animal like a whale, dolphin, or some type of fish.

That said, no animal that we know of makes that volume of sound – the theory countered with the idea that it could be a giant squid or other, still unknown, monster of the deep.

In the end, oceanographer Christopher Fox ended up nailing the source in a 1997 interview.

“I think it may be related to ice calving. It always comes from the south. We’re suspecting that it’s ice off the coast of Antarctica, in which case it’s darn loud.

The Pacific Marine Environmental Laboratory explains that the “bloops” are consistent with icequakes that happen with large icebergs fracture.

“Icequakes are of sufficient amplitude to be detected on multiple sensors at a range of over 3,100 miles. Based on the arrival azimuth, the icebergs generating ‘bloop’ most likely were between Bransfield Straits and the Ross Sea, or possibly at Cape Adare, a well known source of cryogenic signals.”

It’s kind of a relief to know it’s not some ancient sea monster.

But I don’t know. It’s kind of a disappointment, too.

Thought that was fascinating? Here’s another story you might like: Why You’ll Never See A Great White Shark In An Aquarium