One of the biggest canyons in the world was discovered under sheets of ice in Greenland. Comparable to that of Arizona's Grand Canyon, the gorge runs 800 km long and 800m deep.

According to BBC, the canyon was discovered by scientists by accident. They were researching on climate change when their ice-penetrating radars showed Greenland's bedrock.

They reported it to be longer than the Grand Canyon - starting from the center of country to its northern coastline. The gorge is now packed with over 3 km of thick ice.

"It's remarkable to find something like this when many people believe the surface of the Earth is so well mapped," Jonathan Bamber of the University of Bristol in England noted, as reported by The Sun.

According to The Sun's report, the gorge could have been created by an ancient river that eroded rocks before the ice age came and ice covered Greenland some 3.5 million years ago.

The canyon was discovered as scientists tried to discover how Greenland's ice sheet would contribute to the increase in sea level if greenhouse gases continue to warm the Arctic, BBC reported.

"The Greenland and Antarctic ice sheets hide a lot. It's pretty surprising to find this canyon. Greenland isn't that big for a canyon of that size, and for it to survive in its pre-glacial form after successive glaciations is quite something," British Arctic Survey's Prof. David Vaughan told BBC.

However, while the new discovery could help further studies on Greenland's ice sheet flow, Bamber notes it is unlikely that the canyon would help in defining how the melting of ice is affected by global warming.

Notably, according to the British news agency, should the ice sheets melt enough for the canyon to be visible, it would increase sea level by 7 meters and "swamp many major cities." So while this is a breakthrough in geography, many hope that this new Greenland canyon will stay under sheets of ice forever.