Scientists believe that they discovered the largest canyon in Antarctica.
Researchers at Durham University have been analysing satellite images of Antarctica and believe that buried under the snow and ice is a previously undiscovered chasm which measures over 1,000kilometres (621miles) in length and a km in depth at points.
It is over double the size of the Grand Canyon, located in Arizona, which is just 446km (277mi) long.
The team believe that the canyon is winding and is situated in Princess Elizabeth Land – one of the few remaining places to be subjected to human exploration – but is beneath several kilometres of ice.
Canyons are formed by flowing water eroding the walls, but this has confused the team as Antarctica is solid ice as far as the eye can see.
This has led them to two possibilities; one is that the canyon was formed in Earth’s infancy before Antarctica froze over, or that there is or was flowing water beneath the surface.
“Faint traces” of the canyon became visible thanks to satellite imagery, and the scientists then used radio-echo sounding data – where radio waves are sent through the ice to map the surface beneath it.
They found “very large features” which run from Princess Elizabeth Land to the coast around the Vestfold Hills and the West Ice Shelf.
Additionally, they think that it may be attached to a subglacial lake which could be up to 1,250km (777mi) squared – 80 times bigger than Lake Windermere.
Lead researcher, Dr Stewart Jamieson, from the Department of Geography at Durham University in the UK, said: “Our analysis provides the first evidence that a huge canyon and a possible lake are present beneath the ice in Princess Elizabeth Land. It’s astonishing to think that such large features could have avoided detection for so long.
“This is a region of the Earth that is bigger than the UK and yet we still know little about what lies beneath the ice.
“In fact, the bed of Antarctica is less well known than the surface of Mars. If we can gain better knowledge of the buried landscape we will be better equipped to understand how the ice sheet responds to changes in climate.”
Co-Author Professor Martin Siegert, from the Grantham Institute at Imperial College London, UK, said: “Discovering a gigantic new chasm that dwarfs the Grand Canyon is a tantalising prospect.
“Geoscientists on Antarctica are carrying out experiments to confirm what we think we are seeing from the initial data, and we hope to announce our findings at a meeting of the ICECAP2 collaboration, at Imperial, later in 2016.”