A Mariana Trench baleen whale's call is fascinating researchers, not just because it's coming from the deepest part of the Pacific but also because of its wide range of frequencies.
Researchers at Oregon State University who discovered the sound noted that the five-part call includes moans at frequencies as low as 38 hertz and a metallic finale as high as 8,000 hertz, and can last from 2.5 to 3.5 seconds.
"It's very distinct, with all these crazy parts," said Sharon Nieukirk, senior faculty research assistant in marine bioacoustics. "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."
The researchers named the unique call "Western Pacific Biotwang" and said it closely resembles the so-called "Star Wars" sound produced by dwarf minke whales on the Great Barrier Reef off the northeast coast of Australia.
The Mariana Trench, located off Mariana Islands near Guam, is the deepest part of the Earth's oceans, with its Challenge Deep bottoming out at 36,037 feet, said Live Science. It is 1,580 miles long.
Baleen whales are some of the largest animals on earth, characterized by baleen plates and paired blowholes that help distinguish baleen whales from toothed whales, according to the Alaska Fisheries Science Center.
Minke whales are part of the baleen whale family and produce a collection of regionally specific calls, including "boings" in the North Pacific and low-frequency pulse trains in the Atlantic, said the researchers.
"We don't really know that much about minke whale distribution at low latitudes," Nieukirk said. "The species is the smallest of the baleen whales, doesn't spend much time at the surface, has an inconspicuous blow, and often lives in areas where high seas make sighting difficult. But they call frequently, making them good candidates for acoustic studies."
Nieukirk said that researchers hope to identify the new call from past and future data.
The research into the sounds has been published in the Journal of the Acoustical Society of America.