A vast canyon has been discovered beneath Greenland’s ice sheet by geographers studying Nasa data. The enormous valley stretches all the way from Greenland’s central region to the Arctic Ocean in the north, through the Petermann Glacier fjord.
It is estimated to be 800m deep, 10kms wide and 750kms long, making it the world’s longest canyon.
The glacier is believed to have been formed by a river flowing across the landscape during one of Earth’s warmer periods. The researchers believe that as the river flowed towards the ocean, it slowly wore away the rock beneath.
Jonathan Bamber, the head researcher of the study, and his team studied airborne radar data gathered by Nasa, Germany and the UK over several decades in an attempt to establish the landscape beneath Greenland’s dense ice sheet. At certain frequencies, radar is able to penetrate ice and measure how thick it is as well as the shape of the underlying bedrock.
It is believed that the recently-discovered canyon is crucial for transporting meltwater from beneath the ice sheet to the sea. Bamber said the new findings prove that the Earth’s landscape has still to be fully explored and mapped, adding that there remains a lot to be discovered.