Massive Crater Impact Found Under Greenland's Ice | Smart News

Unlike the moon or Mercury, where impact craters dominate the landscape, the pock marks caused by meteorite hits are much harder to find on Earth. That is because of the size of the space, and erosion and rainfall often erase traces of ancient impacts. But some of the depressions survive the eons, and researchers have just found one of the largest ever trapped beneath the ice of Greenland's Hiawatha glacier.

NASA's Operation Icebridge, an airborne mission that uses radar to track changes in ice on Greenland's ice sheet. Researchers from the University of Copenhagen who is an anomaly underneath the ice of Hiawatha that appeared to be a 19-mile-wide, 1,000-foot-deep-crater, which, if confirmed, would be one of the top 25 largest craters known on Earth and the first to be found under the ice. (And it would be big enough to "swallow Washington, DC, writes Paul Voosen at Science.)

The team then spent three years confirming the NASA data. Satellite images appeared to show in the surface of the ice. The team also feels a strong sense of urgency, getting the shots of the 1,000-foot crater rim and the upwellings in the middle that accompany a meteorite strike. The team also collected samples of the sand, which included bits of quartz that can only be formed during a high-energy impact. They do not have to worry about being locked up, the team reports in the journal Science Advances.

The next big questions ask exactly when the meteor hit and what kind of effect it had on the planet.

"The crater is exceptionally well-preserved, and that is surprising, because ice cream is an incredibly efficient erosive agent that would have quickly removed traces of the impact," says lead author Kurt H. Kjær from the Center for GeoGenetics at the Natural History Museum of Denmark in a press release. "But that means the crater must be rather young from a geological perspective. So far, it has not been possible to date it, but it is a condition of it that it has been formed. Greenland, so younger than 3 million years old and possibly as recently as 12,000 years ago last ice age. "

Science's Voosen reports that the impact would have been a pretty big global event. It was believed that the crater, the iron meteor that struck Greenland would have to be half a mile across and would have had the force of a 700 megaton warhead. Such an impact would have been felt hundreds of miles away, would have warmed up the area of ​​Greenland and have rained rocky debris down on North America and Europe.

Some researchers believe it could have had more impact. About 12,800 years ago towards the end of the last ice age, the world was steadily warming up. Then, abruptly, the paleoclimate record shows that the temperature is higher than the average age of a year. According to one theory, a comet impact in Greenland would have melted ice and diluted the ocean current that transports warm water through the Atlantic, causing a re-freeze. Some have even suggested such an event to massive forest fires in Europe and North America, leading to the end of megafauna like the mastodon and the human communities that hunted them, which also disappear from the record around this time.

"It's a very speculative idea, but if it does turn out to be [the link], "Joseph MacGregor, a glaciologist with NASA tells Brian Clark Howard at National Geographic.

But that's only one possibility. In fact, Ludovic Ferriere of the Natural History Museum in Vienna tells us that he is not convinced of the impact of the disease. To be convinced and tested by the end-of-the-year community, the 0.6 mile-thick glacier to collect samples from the crater itself. Let's just hope it is a crater and the buzzing of the drill does not matter the sinister lurking below the ice.

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