The call of an orca. A passing boat propeller. Rushing water from a typhoon.
These are some of the sounds picked up by a special recording device installed seven miles beneath the ocean in the Mariana Trench for three weeks.
"You would think that the deepest part of the ocean would be one of the quietest places on Earth," Robert Dziak, a National Oceanic Atmospheric Administation research oceanographer and chief project scientist, said in a release. "Yet there is almost constant noise. The ambient sound field is dominated by the sound of earthquakes, both near and far, as well as distinct moans of baleen whales, and the clamor of a Category 4 typhoon that just happened to pass overhead."
This is the sound of a whale call:
The hydrophone also picked up the propellor of a passing ship:
As well as the sound of a five magnitude earthquake:
Researchers sent the hydrophone to the area known as Challenger Deep to record continuously for 23 days last in July 2015, according to the National Oceanic and Atmospheric Administration. Because of schedules and persistent typhoons, scientists had to wait until November, to retrieve the device from the ocean floor.
Noise is steadily increasing and these first recordings serve as a baseline for noise levels for scientists to determine in the future if noise levels are growing.
Rising noise levels could affect marine animals like whales, dolphins and some fish that use sound to communicate, navigate and feed.
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