The Julia Sound
The Julia Sound was an inexplicable underwater noise that caught those listening off guard. It happened on March 1st, 1999. No-one has heard it since. This might sound mysterious, but such things are far from unusual in the oceans’ murky depths.
Indeed, there are countless sounds that have never been fully explained. Like Julia, these all have official names — including The Bloop, Upsweep, Slow Down, Whistle and Train. Experts at the US National Oceanic and Atmospheric Administration (NOAA) recorded Julia, but a definitive explanation remains elusive. Julia lasts for around 15 seconds and is eerie indeed.
The likeliest cause is a great iceberg, either breaking up or running aground in the frigid waters of Antarctica. Regardless, Julia could be heard underwater for many miles around. Like The Bloop, Upsweep and all the others, Julia happened, but none can explain why — or predict when or if such a sound will be heard again.