Scientists have been studying Antarctica for over a century, but details as basic as what it looks like beneath all that ice have largely remained a mystery. Now, Earther reports that a team of scientists from Denmark, Norway, the Netherlands, and the UK has published the most comprehensive data yet on the continent's subglacial topography near the South Pole.

As they report in the journal Geophysical Research Letters [PDF], central Antarctica is home to three massive canyons, one of which is deeper than the Grand Canyon and nearly as wide at some points. The researchers made the discovery by flying a plane with radar over the South Pole, a spot that isn't covered by imaging satellites. They expected to find mountains beneath the ice sheet, but the expansive chasms they detected between the mountains came as a surprise.

Of the three canyons, two hadn't been documented previously. The largest, the Foundation Trough, measures 218 miles long, up to 22 miles wide, and 6260 feet deep, putting it up there with the planet's most impressive canyons.

The discoveries are significant on their own, but the real purpose behind the research is to better understand how the West and East Antarctic Ice Sheets will react to rising temperatures. Human-induced climate change has destabilized some of the continent's ice, and the West Antarctic Ice Sheet especially has been slowly crumbling into the sea. If patterns continue, the coastal glaciers supporting the massive ice sheets could collapse, causing sea levels to rise a minimum of 10 feet. If this happens, the canyons could be a major factor in the speed and direction of ice flow from central Antarctica to the coast.

The event isn't likely to happen in the near future, but further study of Antarctica's topography will allow scientists to better predict when it might.

[h/t Earther]