Our directory of things of interest

University Directory

Seismometers buried in Antarctica’s Ross Ice Shelf record its constant song

Seismometers buried in Antarctica’s Ross Ice Shelf record its constant song
21 Jan
2019
Seismometers buried in the Ross Ice Shelf have revealed that its snowy surface constantly vibrates, producing a low rumble of noise that scientists can use to monitor changes

The Ross Ice Shelf is the largest expanse of floating ice on the planet (similar to the size of France). Because of this, it acts as a buttress, holding back the Antarctic glaciers, preventing them from flowing into the ocean. If destabilised – either by the warming ocean below or the warming atmosphere above – this vital role could be diminished, resulting in a rapid rise in sea levels. 

Monitoring the ice shelf is therefore essential and scientists from the American Geophysical Union, suported by the Office of Polar Programs for the US National Science Foundation, have discovered a new tool with which to do so. In 2014, the team buried 34 super-sensitive seismic sensors beneath the ice shelf’s surface, a terrain made up of a thick blanket of snow several metres deep and rippled by massive dunes. The instruments measured seismic signals – the waves of energy produced by movement within the earth. The data revealed that winds whipping across the snow dunes cause the ice shelf’s surface to vibrate. This steady vibration results in the emission of seismic ‘tones’. When processed at a frequency audible to humans, these tones sound like an eerie, warbling hum, a continuous song that would not sound out of place in a sci-fi movie. 

Rick Aster, professor of geophysics at Colorado State University and a member of the team, explains that the tones provide an extremely accurate way of monitoring the ice. This is because when weather conditions change, the pitch of the hum responds. ‘A remarkable thing we discovered during this  study was that even during a relatively subtle warming event that only produced a tiny bit of melt on the ice shelf, we could see very strong indications in this signal,’ he says. ‘It enables us to monitor the temperature and the melting of the surface of an ice shelf on a minute-by-minute basis.’ 

Image 1 Rick Aster 1Rick Aster in the Antarctica with a broadband seismometer. The sensors were buried a few meters into the snow to take measurements

The team are now considering burying the sensors deeper under the ice to monitor vibration at various depths. ‘The first thing to do is to understand the processes and the changes that are happening,’ says Aster. ‘Over 90 per cent of the world’s ice is in Antarctica. As it melts it contributes a greater and greater proportion to rising sea levels and that’s felt all around the world.’   

This was published in the January 2019 edition of Geographical magazine

geo line break v3

Free eBooks - Geographical Newsletter

Get the best of Geographical delivered straight to your inbox by signing up to our weekly newsletter and get a free collection of eBooks!

geo line break v3

Related items

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Climate

Climate NGOs point fingers at nations holding back climate crisis…

Climate

The Paris Agreement has reached adolescence. Its final stages of…

Climate

A report presented at COP25 highlights the trouble with tourism,…

Climate

For the 25th time in history, the United Nations has…

Wildlife

The Wildlife Photographer of the Year’s Rising Star winner brings…

Energy

Abandoned coal mines contain a precious resource in the warm…

Climate

Marco Magrini wonders if the annual gathering of world leadership…

Wildlife

A new animation produced by the charity Born Free raises…

Wildlife

The United States is grappling with a wild pig invasion.…

Wildlife

Increased interest in the farming of endangered animals as a…

Geophoto

Will 2019 go down as the year that the world…

Climate

Large-scale air travel is under public scrutiny, and refusing to…

Climate

A review of climate crisis coverage in the global media…

Oceans

Marco Magrini looks at the carbon capturing power of the ocean’s…

Oceans

Marine Protected Areas are designed to benefit the marine ecosystem…

Climate

The link between China’s economic growth and increased pollution has…

Climate

An analysis of nine year’s worth of lightning data, covering…

Climate

When getting on ‘board’ with sustainability is the entire goal

Oceans

Many scientists believe that jellyfish numbers are increasing, pointing to…

Geophoto

Prepare to be inspired, startled and filled with awe in…