The National Oceanic and Atmospheric Agency (NOAA) sent its submersible, Deep Discoverer, to the depths to investigate the anomaly.  It was first heard as researchers were leading a mapping campaign off the south-east coast this month.  Sonar works by shooting waves of sound outwards and reading the waves that come back after they bounce off objects.

Thinking the bizarre noise could potentially be an undiscovered shipwreck, the team sent the small unmanned sub to search. But instead of finding hordes of sunken gold coins abroad an ancient ship, they found a massive rock formation that was teaming with various species of marine life. In April, the NOAA sent submersibles down to examine a number of shipwrecks off the Gulf of Mexico. READ MORE