Back in the late 1990s, NOAA's Acoustic Monitoring Project recorded a series of haunting, creepy noises from deep beneath the ocean's surface (you can hear it in the audio above). When this recording began to circulate in the media, people went crazy speculating about the sea monsters, secret government experiments, or alien installations that might have generated it. The mystery sound was nicknamed the "bloop," and nobody could figure out a good explanation for it. Until now.
According to this low-key notice from NOAA about the "bloop":
The broad spectrum sounds recorded in the summer of 1997 are consistent with icequakes generated by large icebergs as they crack and fracture. NOAA hydrophones deployed in the Scotia Sea detected numerous icequakes with spectrograms very similar to "Bloop". The icequakes were used to acoustically track iceberg A53a as it disintegrated near South Georgia Island in early 2008. Icequakes are of sufficient amplitude to be detected on multiple sensors at a range of over 5000 km. Based on the arrival azimuth, the iceberg(s) generating "Bloop" most likely were between Bransfield Straits and the Ross Sea, or possibly at Cape Adare, a well know source of cryogenic signals.
You might be disappointed that the bloop didn't come from space whales, but you have to admit that icequakes are pretty awesome too.
[Spotted on Doubtful News]