World's largest canyon may lie under Antarctic: study

Move over, Grand Canyon! The world's largest canyon - over 1,000 kilometre long and up to one kilometre deep - may lie under the Antarctic ice sheet, scientists including those from India have claimed.
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'.

Although the discovery 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 the US, but many times longer, researchers 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 is astonishing to think that such large features could have avoided detection for so long," said Stewart Jamieson from Durham University in the UK who led the study.
"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," he said.

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.
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 1,250 kilometres, more than 80 times as big as Lake Windermere in the English Lake District.
"Our international collaboration of US, UK, Indian, Australian and Chinese scientists are pushing back the frontiers of discovery on Antarctica like nowhere else on earth," said Martin Siegert from Imperial College London.

The research was published in the journal Geology.