The ice sheet that covers Antarctica is ancient, hiding a whole landscape of mountains and valleys that once teemed with life. Using radar and satellite footage, scientists are studying this hidden world — and they just found a 3.2km deep canyon down there.
A new paper in the January issue of the Geological Society of America Bulletin describes how scientists from Newcastle University and Bristol University's Bristol Glaciology Centre measured the chasm. Because the ice sheet is so huge, it was "incredibly serendipitous" that they even found it at all, says lead author Neil Ross. Using radar, the research team penetrated the deep ice to discover a hidden valley known as the Ellsworth Trough, near Ellsworth Lake, where a British team recently drilled down to look for evidence of life.
Scientists have known about such rifts for years, but needed to collect more data about the precise size and shape of them. In this case, Ross' team only had radar data for each end of the valley — and no clue what lay in between.
It turns out that this valley — now canyon — was so big, it could be seen by NASA satellites. That's right: Below miles of ancient ice, the trench was still visible from space. So NASA gave them the data they needed to discover that the trough was actually 3km deep, far deeper than the canyon discovered under Greenlandic ice last year, and also much deeper than the Grand Canyon itself. Ross waxes poetic in a statement:
To me, this just goes to demonstrate how little we still know about the surface of our own planet. The discovery and exploration of hidden, previously-unknown landscapes is still possible and incredibly exciting, even now.
So what actually created this mega-canyon? Well, Antarctica was once part of a single giant continent that dates back hundreds of millions of years. But 80 million years ago, Antarctica (along with India and Africa) broke apart, spinning southward at a pace of 16cm per year (that's light speed, in geological terms). The rift created long valleys and chasms across the warm landscape and then the climate began to cool — glaciers appeared, carving out even deeper chasms.
Image: Newcastle University
These glaciers grew deeper and wider, eventually creating the Antarctica we know today and obscuring the incredible mountain ranges beneath it. It's amazing to imagine that in a few hundred million years, the same process could take place in America, covering our own Grand Canyon under miles of ice, buried until a few intrepid alien geologists rediscover it. [Bristol University; PhysOrg]
Lead image of the Ellsworth Mountains: Shutterstock/ Sasha Fenix.