Alkis

“The deep sound channel was exploited to set up the SOFAR (sound fixing and ranging) system, which was initiated in 1960 by the Australia-Bermuda Sound Transmission Experiment, in which explosions were set off near Heard Island in the Indian Ocean off the coast of Australia. They were detected in Bermuda, at a distance of 20,000 km. A new, unexpected sound was discovered by the SOFAR researchers, and later identified as the calls of fin whales (Balaenoptera physalus), who long ago discovered the existence and properties of the deep sound channel and regularly visit it to signal their distant kin.”
― Mike Goldsmith, Sound: A Very Short Introduction

“So, here you are
too foreign for home
too foreign for here.
Never enough for both.”
― Ijeoma Umebinyuo, Questions for Ada

“Whatever can happen at any time can happen today.”
― Seneca, On the Shortness of Life: Life Is Long if You Know How to Use It

“The distances over which sound can travel underwater are amazing. It is believed that before the proliferation of engine-powered vessels, Antarctic whales could be heard by their Arctic cousins. Such vast ranges are possible partly because sound waves are absorbed far less in water than in air. At 1 kHz, absorption is about 5 dB/km in air (at 30 per cent humidity) but only 0.06 dB/km in seawater. Also, underwater sound waves are much more confined; a noise made in mid-air spreads in all directions, but in the sea the bed and the surface limit vertical spreading.”
― Mike Goldsmith, Sound: A Very Short Introduction