The mysterious sound heard in Mariana Trench that has baffled scientists is likely a new baleen whale call that no one has heard before.
The sound, which lasts up to 3.5 seconds, was recorded on several occasions from Autumn 2014 to Spring 2015 deep in the Mariana Trench Marine National Monument, one of the largest marine protected areas worldwide.
Mysterious Sound Does Not Resemble Any Human Or Geologic Origin
The sound spans in frequencies ranging from as low as 38 hertz and as high as the 8,000 hertz metallic finale. Scientists were initially puzzled over the source of the five-part sound because they were not able to identify any human or geologic origin.
Sharon Nieukirk, from Oregon State University, and colleagues said that the sound is not similar to man-made sources such as seismic airguns and ships. The noise neither resembles those of geophysical sources such as ice and earthquake as well as rain and wind.
Nieukirk and colleagues said that the complex sound could possibly be from a biological source and proposed that it could be a new call from baleen whales that has not yet been identified before.
Resembles The "Star Wars" Sound Produced By Baleen Whales In Australia
Although the sound is new and unique, Nieukirk's team got a clue from the recordings of sounds heard at the Great Barrier Reef in Australia that were produced by dwarf minke whales, a type of baleen whale.
In 2001, ocean scientist Jason Gedamke discovered that dwarf minke whales off the waters of the Great Barrier Reef were the source of the call he dubbed the "Star Wars" sound. The call is a mix between the beating of an oil drum and a firing laser gun.
The mysterious sound in Mariana Trench that researchers called the "Western Pacific Biotwang" resemble the "Star Wars" call. Based on the similarities in the frequency and structure of the two sounds, Nieukirk and colleagues think that the Western Pacific Biotwang is likely produced by the same type of animal.
"Here we have presented a first report of recordings of a novel call we believe to be from a baleen whale, most likely a minke whale," the researchers wrote in their study, which was published in the Journal of the Acoustical Society of America.
"More data are needed, including genetic, acoustic, and visual identification of the source to confirm the species and gain insight into how this sound is being used."
Photo: Oregon State University | Flickr