Climate change is affecting the speed of sound in the Arctic Ocean

Nautilus : The speed of sound varies in water: The colder the temperature, the slower sound travels. The phenomenon is important for underwater communications, such as the sonar used by the US Navy. Since about 1975 ocean water flowing below the icy surface of the Beaufort Sea in the Arctic Ocean has been warming due to climate change. The result is a channel of warmer water called the Beaufort Lens, which stretches from Alaska to the Northwest Territories. Its multilayer structure allows sound to travel through it much farther and faster than expected. To get a better idea of the sound channel’s acoustic properties, a team of scientists with the navy and MIT traveled there in March and dropped a 385 kg, 3.5 m drone through the ice. Another foray with a more precise and complex measurement system is already being planned for 2018.