In 1997, the US NOAA Came Across a Loud Sound Deep in the Sea. It Remains a Mind-Boggling Mystery to Date

For a long time, 'Bloop' was one of the biggest mysteries encountered by experts in the deep sea. The sound was first detected back in 1997 within the Pacific Ocean, stated LAD Bible. Researchers were unable to figure out the origin of the sound. After around a decade, experts from the U.S. National Oceanic and Atmospheric Administration (NOAA) found a plausible source.

The sound has been put out on YouTube, and there, too, it has created a frenzy. It appears to be a bunch of vibrations during the first listening session. At some points, the sound seems to be louder. However, the pattern remains the same, which possibly indicates that the origin of the 10-second clip is one source, and not many. The video was put out in 2017, and to date has garnered 1.4 million views. 

The comment section was filled with different takes and speculation. @ElizabethV_official suggested a possible source and wrote, "This sounds like an old motorcycle taking off with less fuel. But otherwise scary!!!" @CYBERXHEX believes the sound's effect and its name are not suitable and commented, "What takes all the intimidation out of it is the fact that it's called 'the bloop.'"

The first instance of the sound was captured by hydrophones, or underwater microphones, placed at a distance of 3,219 kilometers from each other, in the Pacific, stated NOAA. After the first time, it was recorded several other times in the Pacific Ocean. Experts associated with the NOAA’s Pacific Marine Environmental Laboratory (PMEL) took into consideration multiple theories when investigating the source of the sound. The possibilities included fishing boat winches, whales, giant squids, ship engines, an unknown creature, and even confidential military exercises. Nothing was left out of the realm of exploration.

It was in 2005 that experts finally managed to figure out the cause. Their exercises and their results made the team conclude that the thunderous sounds were coming from the cracking of the iceberg and its eventual shifting away from the Antarctic glacier. The whole process is called icequake, and according to experts, more and more instances of this event are happening on Earth's southernmost landmass.

To verify the claim, scientists from PMEL took an exhaustive acoustic survey, according to Discover Magazine. This survey took place around the Drake Passage, the place between the South Shetlands and the Antarctic Peninsula, as well as the area in the middle of South America and the South Shetland Islands of Antarctica. It was essentially in the Antarctic Peninsula where they found most instances of these sounds and icequakes. In 2010, the survey came to an end. Researchers believe that more instances of icequakes are primarily happening because of increased global warming. This, in turn, resulted in more reverberations of this bewildering sound through the Pacific Ocean.

In 2012, scientists from NOAA reaffirmed the origin, according to the LAD Bible. This brought to a close a decade-old mystery, and showed how the 'monster' behind the intimidating sound wasn't any creature, but essentially human activities.