Is it a fish? Is it a sea monster? Is it Cthulhu?
In 1997, while using underwater microphones to monitor volcanic activity in the depths of the southern Pacific Ocean, researchers with NOAA’s Pacific Marine Environmental Laboratory (PMEL) recorded a mysterious sound. It was extremely loud and, well, weird. The fact that no one, including NOAA, had any idea what was making the noise fed theories like the ones above. The sound came to be called “the bloop” and remained a mystery for more than a decade.
Like everyone else on the planet, the PMEL researchers wanted to know what was behind the bloop, but so little of the ocean has been explored (less than five percent, according to NOAA) that tracking down the source of one weird sound among many was not realistic. So they did what scientists do; they carried on, continuing to record and study the sounds of seafloor volcanoes and earthquakes.
From 2005 to 2010, the PMEL researchers took their acoustic survey to the area around the Drake Passage, between the tip of South America and the South Shetland Islands of Antarctica, and to the Bransfield Strait, between the South Shetlands and the Antarctic Peninsula. And there they found the source of the bloop.
