Chinmaya IAS Academy – Current Affairs Chinmaya IAS Academy – Current Affairs
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Buried beneath a kilometre of snow and ice in northern Greenland, scientists have uncovered an asteroid impact crater, bigger than the area of Paris. This is the first time that a crater of any size has been found under one of Earth’s continental ice sheets, said researchers from the University of Copenhagen in Denmark. The researchers worked for the past three years to verify their discovery, initially made in the 2015. The crater measures more than 31 km in diameter, placing it among the 25 largest impact craters on Earth, according to the study published in the journal Science Advances . It was formed when a kilometre-wide iron meteorite smashed into northern Greenland. “The crater is exceptionally well-preserved, and that is surprising, because glacier ice is an incredibly efficient erosive agent that would have quickly removed traces of the impact,” said Professor Kurt H. Kjaer from the Natural History Museum of Denmark. “So far, it has not been possible to date the crater directly, but its condition strongly suggests that it formed after ice began to cover Greenland, so younger than 3 million years old and possibly as recently as 12,000 years ago — toward the end of the last ice age,” he said. The crater was first discovered in July 2015 as the researchers inspected a new map of the topography beneath Greenland’s ice-sheet. They noticed an enormous, but previously undetected circular depression under Hiawatha Glacier. “We immediately knew this was something special but at the same time it became clear that it would be difficult to confirm the origin of the depression,” said Mr. Kjaer. The 20-tonne iron meteorite sits in the courtyard at the Geological Museum in Copenhagen.
