Punta Arenas

The Bloop

In 1997 hydrophones belonging to the US National Oceanic and Atmospheric Administration recorded an ultra-low-frequency sound in the South Pacific loud enough to be picked up by sensors three thousand miles apart. Its profile resembled a biological one, and for two decades the Bloop was the leading exhibit for anyone who believes in undiscovered giants in the ocean. NOAA settled it in 2012: an icequake, an iceberg fracturing off Antarctica. The sound stopped being a mystery but remains one of the best-known audio files in internet history.