In 1997, underwater sensors picked up a sound so loud and powerful it was captured by hydrophones over 3,000 miles apart. It had the acoustic signature of a living creature, but any animal capable of making it would have to be far larger than any whale ever recorded. Was a monster lurking in the deep?

This episode dives into the Bloop, one of the most famous acoustic mysteries of the deep sea. We explore how Cold War submarine-detection technology, eager media speculation, and the titanic forces of glacial ice intersected to create a modern myth. It matters because the truth, the Earth itself breaking apart, is far more awe-inspiring than any leviathan.

• How the SOSUS network built to hunt Soviet submarines ended up listening to the ocean
• The deep sound channel that acts as an acoustic superhighway across ocean basins
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