A satellite data suggests that the world's largest canyon thought to be more than 1,000 kilometres long and a kilometer deep may be present beneath the Antarctic ice sheet.
Although the discovery led by Durham University needs to be confirmed by direct measurements, the previously unknown canyon system is thought to be over 1,000km long and in places as much as 1km deep, comparable in depth to the Grand Canyon in USA, but many times longer.
An airborne survey taking targeted radio-echo sounding measurements over the whole buried landscape is now underway with the aim of unambiguously confirming the existence and size of the canyon and lake system, with results due later in 2016.
The canyon system is made up of a chain of winding and linear features buried under several kilometres of ice in one of the last unexplored regions of the Earth's land surface: Princess Elizabeth Land (PEL) in East Antarctica. Very few measurements of the ice thickness have been carried out in this particular area of the Antarctic, which has led to scientists dubbing it one of Antarctica's two 'Poles of Ignorance'.
The researchers believe that the landscape beneath the ice sheet has probably been carved out by water and is either so ancient that it was there before the ice sheet grew or it was created by water flowing and eroding beneath the ice.
Although not visible to the naked eye, the subglacial landscape can be identified in the surface of the ice sheet.
In a research published in the journal Geology and titled Antarctica: Explorers, Heroes, Scientists the research team was composed of scientists from Newcastle University, Imperial College London and Durham University in the UK, University of Texas at Austin, USA, University of Western Australia, Australian Antarctic Division, University of Tasmania in Australia, and the Polar Research Institute of China.
Faint traces of the canyons were observed using satellite imagery and small sections of the canyons were then found using radio-echo sounding data, whereby radio waves are sent through the ice to map the shape of the rock beneath it. These are very large features which appear to reach from the interior of Princess Elizabeth Land to the coast around the Vestfold Hills and the West Ice Shelf.
The canyons may be connected to a previously undiscovered subglacial lake as the ice surface above the lake shares characteristics with those of large subglacial lakes previously identified. The data suggests the area of the lake could cover up to 1250km, more than 80 times as big as Lake Windermere in the English Lake District.
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.
Co-Author Dr Neil Ross from Newcastle University in the UK, said, Antarctic scientists have long recognised that because the way ice flows, the landscape beneath the ice sheet was subtly reflected in the topography of the ice sheet surface.
Content Credit: https://www.dur.ac.uk/research/news/item/id=26788&itemno=26788