Question: How does a canyon that's 500 miles long and deep - bigger than Arizona's Grand Canyon - escape notice?
Answer: When it's covered by ice.
But it's a secret no more. Climate change scientists have stumbled upon it in Greenland while peeking at bedrock there via radar. The BBC reported:
The British Antarctic Survey said it was remarkable to find so huge a geographical feature previously unseen. The hidden valley is longer than the Grand Canyon in Arizona. It snakes its way from the centre of Greenland up to the northern coastline and before the ice sheet was formed it would have contained a river gushing into the Arctic Ocean. Now it is packed with ice.
One day we might be able to see the canyon with the naked eye because Greenland's ice is melting - which is why the researchers were there in the first place. They were trying to determine the effect of the melt on rising ocean levels.
While they were gathering data, up popped the surprise canyon, prompting lead author Prof. Jonathan Bamber from England's Bristol University to say:
"With satellite images instantly available on a mobile phone we could assume that the Earth has been fully mapped, but there's clearly a lot left to discover. We're incredibly excited about this - it really is a once-in-a-lifetime discovery to find something on this scale."
The scientists say humans have never seen the canyon. The ice in Greenland is up to 2 miles thick and is so heavy that it is causing the country to sag in the middle. Central Greenland was about 1,640 feet above sea level, and is now about 656 feet.
If all of Greenland melts, sea levels will rise by an estimated 22 feet, which would swamp many major cities. Hopefully we won't be hiking into the canyon anytime soon.
Photo of Grand Canyon from Roger Bolsius via Wikimedia
More from Greenland:
This post was originally published on Smartplanet.com