The first audio recordings taken from the deepest point on the Earth’s surface have reveal a number of amazing sounds, including the calls of different species of whale.
Little is known about what happens in the Mariana Trench, located at the bottom of the Pacific Ocean around 322 km (200 miles) southwest of Guam, but the recording do shed some light on what is a dark place (where the sun never shines).
The crushing pressure levels at such extreme depths prevent in-depth exploration and so a team from US National Oceanic and Atmospheric Administration (NOAA) decided to listen in at least by dropping a titanium-encased recording device (hydrophone) down to Challenger Deep, the trench’s deepest point.
Aside from whale song, over a 23 day period the researchers recorded the propeller of a boat travelling across the surface 10.9 km (6.7 miles) away, the sound of a typhoon raging overhead and the rumbling of earthquakes.
The purpose of the research work is to help determine if human-created noise in the ocean is getting louder, and so measure the impact on marine animals that use sound to communicate, navigate and feed, such as whales and dolphins.