6 mysterious structure found in Greenland 2021
*The world's longest canyon
The Greenland ice sheet hides 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)
* Invisible mountains
The canyon isn't the only rugged part of Greenland's under-ice landscape. Decades of mapping the island by ice-penetrating radar (which is usually mounted on airplanes) have revealed rugged mountain rangesand plunging fjords beneath the ice sheet.
*A primeval lake
Hundreds of thousands or millions of years ago, before Greenland was covered with ice, . Today, the lake is a depression filled with sediment. But it was once filled with water 800 feet (250 m) deep in some places. The lake basin covers 2,700 square miles (7,100 square km) and was fed by at least 18 different streams.
* Hidden gems
Greenland's ice sheet also hides a landscape of jewel-like lakes filled with crystalline meltwater. There are at least 60 of these small lakes,
* Evidence of meteor impacts
Not all the topography below the ice sheet is of Earthly origin. Scientists have found at least two likely meteor craters buried beneath the ice. Both are in northwest Greenland.
* Perfectly preserved fossil plants
An ice core dug up during a Cold War-era attempt at building a nuclear weapons base was rediscovered in a freezer in 2017 and found to hold the perfectly preserved fossils of plant dating to a million years ago.
credit : Stephanie Pappas
(Stephanie interned as a science writer at Stanford University Medical School)
