A huge crater in northwest Greenland, buried under a thick layer of ice and first seen in 2015, is much older than suspected – formed by a meteorite impact 58 million years ago, rather than 13,000 years ago. behind.
Scientists said Wednesday that they used two different methods of dating sand and rock left over from the impact to determine when the crater – about 31 kilometers wide – formed.
They found that the meteorite – about 1.5 to 2 km in diameter – hit Greenland about 8 million years after a larger asteroid impact in Mexico’s Yucatan Peninsula wiped out the dinosaurs.
The crater lies beneath Greenland’s Hiawatha Glacier, covered by a 1 km deep layer of ice. It remained undetected until radar data alerted scientists to its existence.
It is one of the 25 largest known impact craters on Earth. Over the eons, Earth has been hit by space rocks countless times, although gradual changes in the planet’s surface have erased or obscured many of the craters.
Greenland at the time – during the Paleocene epoch – was not the icy place it is today and was instead covered in temperate rainforests, populated by a variety of trees and inhabited by some of the mammals that became land animals. dominant on Earth after the dinosaurs went extinct.
The meteorite released millions of times more energy than an atomic bomb, leaving a crater big enough to engulf the city of Washington.
“The impact would have devastated the local region,” said Swedish Museum of Natural History geologist Gavin Kenny, lead author of the research published in the journal Science Advances.
