Julia is the moniker given to the unknown source of a sound recording made on March 1, 1999. It was recorded in the eastern equatorial Pacific using an automated hydrophone array.
The source of the sound, which was heard for thousands of kilometers, was commonly assumed to be an iceberg aground somewhere off Antarctica’s coast. Between the Bransfield Straits and Cape Adare is where it all began.
However, a secret picture that subsequently surfaced, a classified image that was later redacted, collected by a NASA satellite, shows something with a large shadow in the seas of Cape Adare at the time, which, if verified as a live creature, would be classed as a giant sea monster.
The National Oceanic and Atmospheric Administration, or NOAA for short, has caught and aired a variety of strange underwater monster noises during the previous several years.
The Upsweep is an unidentified sound that was picked up by the American NOAA’s equatorial autonomous hydrophone arrays. This sound was present when the Pacific Marine Environmental Laboratory started recording its sound surveillance system, SOSUS, in August 1991. It’s made up of a series of short, narrow-band upsweeping noises, each lasting a few seconds. The source volume was loud enough to be heard on the other side of the Pacific.
The sound seems to be seasonal, peaking in the spring and fall, but no one knows why. The sound’s origin is unclear, however, it is commonly located about 54°S 140°W, near the region of volcanic activity.
The Whistle was recorded in the Mariana volcanic arc in the Pacific Ocean, but it is categorized as “unidentified” because it was only caught on one hydrophone rather than the three necessary to establish a location.
Bloop is the name given to a loud ultra-low-frequency underwater sound found by the US National Oceanic and Atmospheric Administration in 1997. The sound was heard many times and was approximately triangulated to a distant spot in the south Pacific Ocean west of South America’s southern point.
It rose in frequency fast over one minute, according to the NOAA report, and had enough amplitude to be detected by many sensors at a distance of more than 5,000 kilometers.
Dr. Christopher Fox thinks it is neither the consequence of a man-made event like a submarine or a bomb nor is it linked to natural occurrences like volcanoes or earthquakes.
The acoustic profile of Bloop closely resembles that of a live thing. The source is unclear, however, since the sound is unlike any other known sound and is many times louder than the world’s loudest mammal, the blue whale.
Slow Down, a weird deep-sea sound, was recorded in the Equatorial Pacific Ocean on May 19, 1997. The word was chosen because the sound’s frequency progressively decreases over the duration of seven minutes. An automated hydrophone array was used to catch it. Every year since 1997, the sound has been captured many times.
Finally, the Train is the name given to a sound recorded on March 5, 1997, by an automated hydrophone array in the Equatorial Pacific Ocean. The sound’s frequency rises to a near-constant level. The origins of this sound, which are also in Cape Adare, Julia’s identical geographical location, are extremely interesting.
Could any of these sounds be undiscovered marine creatures’ mating calls? Maybe one day. We’ll figure it out…