You recall the old joke about place names: Iceland is nice and green, but Greenland is covered with ice. Specifically an ice sheet 9,800 feet (3,000 meters) thick. You might wonder what, exactly, is underneath all that ice. Thanks to radar technology, we are getting an idea, and it appears the geography of Greenland is quite varied. For example, it contains the longest canyon in the world!
Discovered in 2013, the canyon stretches 460 miles (740 kilometers) from the highest point in central Greenland to Petermann Glacier on the northwest coast. That's significantly longer than China's 308-mile-long (496 km) Yarlung Tsangpo Grand Canyon, the longest canyon on the planet that you can actually see.
The canyon plunges up to 2,600 feet (800 m) deep in places and is 6 miles (10 km) wide. For comparison, the Grand Canyon in Arizona averages about 1 mile (1.6 km) deep and 10 miles (16 km) across.
Parts of the canyon may route meltwater from beneath the ice sheet to the sea. It probably formed before the ice sheet and was once the channel for a mighty river.
There are also mountains, huge freshwater lakes, meteor craters, fossils, and more! Learn the secrets Greenland is keeping on ice (for the moment) at Space.com. -via Damn Interesting
(Image credit: NASA's Goddard Space Flight Center/ Cynthia Starr)
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