Mystery of ‘alien song’ coming from one of Earth’s deepest points finally solved

The mysterious noises coming from the Mariana Trench have finally been explained — after fears that the spooky sounds were an alien invasion.

Hailed as one of the most mysterious places on Earth, the 37,000ft deep trench can be located at the floor of the Pacific Ocean, where few have ventured.

In 2014, eerie sounds coming from the trench were recorded, lasting between 2.5 and 3.5 seconds.

Their source was unknown, but scientists dubbed the noises as ‘biotwangs’.

Now, ten years later, scientists from the National Oceanic and Atmospheric Administration (NOAA) have reanalysed the sounds — and sorry to all the believers out there, but they weren’t alien calls.

The sounds were recorded by underwater gliders, that were used to carry out acoustic surveys of the Mariana Trench, the Mail Online reported.

Deep moans at frequencies between 38 and 8,000 hertz could be heard on the five-part sounds, baffling researches.

In 2016, scientists from Oregon State University (OSU) proposed that the peculiar sound could be a previously unheard baleen whale call.

Sharon Nieukirk, senior faculty research assistant in marine bioacoustics at the university revealed at the time: ‘It’s very distinct, with all these crazy parts.

‘The low-frequency moaning part is typical of baleen whales, and it’s that kind of twangy sound that makes it really unique. 

‘We don’t find many new baleen whale calls.’

Eight years on, researchers have analysed the noises again, but this time using a combination of visual and acoustic survey data.

The new study led by Dr Ann Allen explained that the team at OSU were not far off – and Bryde’s whales were actually to blame for the peculiar sounds.

The findings, published in the Frontiers in Marine Science journal, revealed: ‘It was assumed to be produced by a baleen whale, but without visual verification it was impossible to assign a species.

‘Using a combination of visual and acoustic survey data collected in the Mariana Archipelago, we determined that biotwangs are produced by Bryde’s whales.’

The large mammals can be found across the globe, and enjoy warm temperatures in oceans such as the Atlantic, Indian and Pacific.

To verify that these whales were the source of the calls, the team used artificial intelligence to confirm their findings.

‘We used a combination of manual and machine learning annotation methods to detect biotwangs in our extensive historical passive acoustic monitoring datasets collected across the central and western North Pacific,’ the study explained.

‘We identified a consistent seasonal presence of biotwangs in the Mariana Archipelago and to the east at Wake Island, with occasional occurrence as far away as the Northwestern Hawaiian Islands and near the equator (Howland Island).’

Speaking to Popular Science, lead researcher Dr Allen explained a theory behind the whales’ unusual call: ‘It’s possible that they use the biotwang as a contact call, a sort of “Marco Polo” of the ocean. 

‘But we need more information before we can say for sure.’

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