Vast canyon discovered under Greenland

A vast hole in the Earth on the same scale as the Grand Canyon lies buried under ice in Greenland, scientists have learned.

The hidden mega-canyon is at least 466 miles (740km) long and up to 2,624ft (800m) deep in places.

The feature, resembling a meandering river channel, is believed to pre-date the ice sheet that has covered Greenland for millions of years.

Professor Jonathan Bamber, from the school of geographical studies at University of Bristol, said:

"With Google Streetview available for many cities around the world and digital maps for everything from population density to happiness, one might assume that the landscape of the Earth has been fully explored and mapped.

"Our research shows there's still a lot left to discover."

The canyon was uncovered by airborne radar which can penetrate ice and bounce off the land beneath.