The Southern Ocean is punctuated by an amazing variety of sounds — chirps and clicks and notes that sound like they were created for a sci-fi movie. Yet they’re produced by seals and whales, by grinding icebergs and cracking ice sheets, and by things that scientists are still trying to identify.
PALOAO station on the ice shelf of Atka Bay in the Antarctic. Credit: Lars Kindermann / Alfred-Wegener-Institut, GermanyA set of underwater microphones is recording the sounds of the Southern Ocean around the clock, all year long. It’s a project known by the acronym PALOAO, from the Hawaiian word for whale, that’s conducted by the Alfred Wegener Institute in Germany. It’s operated from a remote station atop the Ekstrom Ice Shelf in Atka Bay off the coast of Antarctica.
There are few human-made sounds — only an occasional ship bringing supplies to a nearby research station. Many creatures use sound to navigate, hunt, and “talk” to each other, so the lack of human-made sounds provides a pristine environment for scientists to study.
The sounds will help scientists track the motions and behavior of many species all year long — Weddell seals, Ross seals, and others.
The sounds also reveal the natural environment — collisions between icebergs, and the rumbles and splashes of ice breaking off the shelves and falling into the sea.
And they reveal sounds that no one can explain — some audible mysteries from the cold depths of the Southern Ocean.
