A dramatic gash in the surface of the Earth that could rival the majesty of the Grand Canyon has been discovered secreted beneath Antarctica's vast, featureless ice sheet.

Dubbed the Ferrigno Rift for the glacier that fills it, the chasm's steep walls plunge nearly a mile down (1.5 kilometers) at its deepest. It is roughly 6 miles (10 km) across and at least 62 miles (100 km) long, possibly far longer if it extends into the sea.

The rift was discovered during a grueling 1,500-mile (2,400 km) trek that, save for a few modern conveniences, hearkens back to the days of early Antarctic exploration. And it came as a total surprise, according to the man who first sensed that something incredible was literally underfoot, hidden by more than a half-mile (1 km) of ice.

 Old-school exploration

Robert Bingham, a glaciologist at the University of Aberdeen, along with field assistant Chris Griffiths, had embarked on a nine-week trip during the 2009-2010 field season to survey the Ferrigno Glacier, a region humans had visited only once before, 50 years earlier. Over the last decade, satellites have revealed the glacier is the site of the most dramatic ice loss in its West Antarctica neighborhood, a fringe of coastline just west of the Antarctic Peninsula — the narrow finger of land that points toward South America.

The two-man team set out aboard snowmobiles, dragging radar equipment behind them to measure the topography of the rock beneath the windswept ice, in a region notorious for atrocious weather. Braced for arduous, yet uneventful fieldwork, the surprise came right away. 

"It was literally one of the first days that we were driving across the ice stream, doing what we thought was a pretty standard survey, that I saw the bed of the ice just dropping away," Bingham said.

The drop was so sudden and so deep that Bingham drove back and forth across the area two or three more times to check the data, and saw the same pattern. "We got the sense that there was something really exciting under there," he told OurAmazingPlanet. "It was one of the most exciting science missions I've ever had."