Radar reveals vast chasm

A VAST and previously unmapped gorge 800m deep has been found under ice in Greenland. It is comparable in size to parts of the Grand Canyon in the US.

Another study in 2012 revealed a rift valley entombed in Antarctica’s ice, which scientists said might be speeding the flow of ice towards the sea. In 2009, a jagged “ghost range” of mountains buried in Antarctica was spotted.

“It’s remarkable to find something like this when many people believe the surface of the earth is so well mapped,” said Jonathan Bamber of the University of Bristol in England. He is the main author of the article on the Greenland canyon, which appears in the latest edition of the journal Science.

An ice-penetrating radar was used to map the area.

The canyon is 750km long in central and north Greenland and comparable in scale to parts of the Grand Canyon, which is twice as deep — 1.6km — at its deepest point. The Greenland canyon is buried under about 2km of ice.

About as long as the Rhone River in France and Switzerland, the ravine was probably cut by an ancient river that eroded rocks as it flowed north before temperatures cooled and ice covered Greenland 3.5-million years ago, the scientists have written in the report.

The gorge probably still plays a role in draining some meltwater from beneath the ice sheet.