Researchers believe they have identified the source of a bizarre and baffling 'alien sound' recorded near the Mariana Trench.
The puzzling metallic noise, called the 'Western Pacific Biotwang,' was discovered a few years ago by a special underwater robot designed to listen for oceanic acoustics.
At the time, scientists were flummoxed by the strange series of sounds, but further investigation has led them to conclude that it may actually be a never-before-heard type of whale call.
Based on its similarities to the sounds emitted by minke whales around Australia, marine bioacoustics experts suggest that the mysterious noise could have come from such creatures living in the area.
The unique nature of the call would be akin to these Mariana Trench minke whales developing their own regional dialect akin to humans that speak with an accent.
Although the experts are fairly confident that they know where the call came from and hope to confirm their conclusion by analyzing other known minke whale sounds, what it might mean is still a mystery.
Since it was heard in both the autumn and spring, it appears that the call is not connected to seasonal activities and could contain a complex message being shared between the massive mammals.
Given the surreptitious nature in which the sounds were recorded, perhaps the call is a warning from the whales to their friends that someone is eavesdropping on them.
Source: Live Science