Researchers release audio of Antarctic ice ‘singing’ a haunting song

17 Oct 2018

Image: © river34/Stock.adobe.com

We may have a new way of monitoring the movement of Antarctic ice from afar, just by listening to it ‘singing’.

As the IPCC report and a multitude of other studies have shown, the world’s ice in the Arctic and Antarctic is under severe threat from climate change. This means it is more important than ever that we keep a vigilant eye on any major changes in ice shelves.

Now, according to a team of researchers from the American Geophysical Union, it might be possible to monitor the Antarctic from great distances thanks to its ability to ‘sing’.

A paper published to Geophysical Research Letters revealed how winds blowing across the snow dunes on the continent’s Ross Ice Shelf causes the massive ice slab’s surface to vibrate. This produces a near-constant set of seismic ‘tones’ that are easy to monitor.

Tracking changes in the ice shelf is crucial as, after they collapse, the resulting ice can raise sea levels significantly. In Antarctica, ice shelves have been thinning, and in some cases retreating, due to rising air and ocean temperatures.

So, in order to better understand how they move, the researchers buried 34 extremely sensitive seismic sensors under the ice shelf’s snowy surface, allowing them to measure vibrations and study structure movements for a period of more than two years.

Singing with a fur coat

The resulting data showed something strange: the ‘fur coat’ snow layer that protects the ice from heat was constantly ‘singing’, or vibrating. After looking closer at the data, they discovered winds whipping across the massive snow dunes caused the ice sheet’s snow covering to rumble, like the pounding of a colossal drum.

The pitch of this hum also changed when weather conditions altered the snow layer’s surface, vibrating at different frequencies when strong storms rearranged snow dunes or when the air temperatures at the surface increased or deceased.

One of the researchers, Julien Chaput of Colorado State University, said: “It’s kind of like you’re blowing a flute, constantly, on the ice shelf”, with each note change indicating a major structural change.

“Either you change the velocity of the snow by heating or cooling it, or you change where you blow on the flute, by adding or destroying dunes,” he said. “And that’s essentially the two forcing effects we can observe.”

With this newfound ability, researchers could use seismic stations to continuously monitor the conditions on ice shelves almost in real time, allowing us to see how the ice shelf’s snow jacket is responding to changing climate conditions.

Colm Gorey was a senior journalist with Silicon Republic

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