The Mysteries of the Mariana Trench

The Mariana Trench mystery sound

One of the strangest things that have emanated from the Mariana Trench hasn’t been a frightening sea monster, though we’d be surprised if the option isn’t on the table whenever the mysterious “bio-metallic” sound that sometimes emanates from the trench is heard. Marine researchers have dubbed this almost mechanical, “twangy” noise “Western Pacific Biotwang,” and it first turned up in 2014 when scientists recorded ocean sounds near the Mariana Trench with diving robots called “passive acoustic ocean gliders.”

The complex, 3.5-second sound turned up several times during the research period, and while it seemed mysterious, the scientists eventually decided that the most likely culprit is a minke whale, a peculiar small whale that can sound like a Star Wars sound effect. However, the minke whales themselves remain largely a mystery to science, and they still have no idea what the call is about, and why it has been recorded year-round.

Incidentally, this isn’t the first time the elusive minke whales have puzzled scientists. For 50 years, researchers were puzzled by a strange, duck-like underwater sound that seemed too repetitive and rhythmical to be anything but man-made, and far too loud to be a fish. We didn’t figure out that this “bio-duck” sound was minke whales until 2014.