A team of US scientists from several marine science centers and institutions claims to have identified the source of one of the strangest sounds ever recorded in the depths of the Earth's oceans, in the form of an alien metallic moaning, nicknamed the Western Pacific Biotwang.
The 3.5-second sound was first recorded between fall 2014 and spring 2015, by an autonomous vehicle collecting acoustic data in the Mariana Trench, the deepest known part of the Pacific Ocean. The unique and complex sound consisted of two parts: one long, low sound with long attack, and a series of shorter, high-pitch sounds, similar to that of an alarm. Both parts have a distinct "metallic" aspect, making them sound somewhat like machinery.
After many months of speculation, a team of scientists has come to the conclusion that this sound is biological.
"The sounds reported here are not similar to known anthropogenic sources such as noise produced by ships or seismic airguns," the team said in a report.
"They also do not resemble geophysical sources such as the very low-frequency sounds produced by earthquakes and ice, nor the sounds produced by wind or rain…. [We] hypothesise that these complex sounds were produced by a biological source."
"The complex structure of the Western Pacific Biotwang sound, the frequency sweep, and the metallic nature of the final part of this call are all very similar to characteristics of dwarf minke whale Star Wars calls," the team reported.
The Minke Whale (Balaenoptera acutorostrata) is the second smallest baleen whale pic.twitter.com/UN5ttiPa1u— vicente gonzalez (@herrerillo) 30 ноября 2016 г.
Dwarf minke whale are a subspecies of the common minke whale, a species of baleen whales. Baleen whales, named after their trademark mouth plates used to filter krill and small fish from seawater, are known for complex vocalizations, primarily used as mating calls. These vocalizations are said to resemble the sound of fictional handheld weapons, called blasters, used in the Star Wars movie franchise.
But the Western Pacific Biotwang call stands out in that it has been identified several times during the year, while mating calls are normally heard only during the winter mating season, according Sharon Nieukirk, one of the scientists from Oregon State University.
If this sound is revealed to be that of a baleen whale, its purpose must then be identified, researchers say.