An international team of scientists discovered a 31-kilometer diameter meteorite crater north of Greenland. This is the first time a crater has been found under continental ice sheets. The Science Advances magazine article is published by Nplus1.
The crater under a kilometer-high ice sheet is located in the 25th place in size on Earth and in an area larger than Paris. Scientists believe that it was formed when an iron meteor fell one to one and a half kilometers in diameter.
A crater of about 300 meters was discovered in July 2015 under the Great Glacier when analyzing data from aerial observations collected by the IceBridge mission, led by NASA, and data from the American Terra and Aqua satellites.
After that, they found the nature of the crater and confirmed the hypothesis of the origin of the meteor. The key evidence of this is that scientists found in three sediment samples that melting water flowed out of the crater: quartz sand, according to scientists, had signs of a meteorite impact. In addition, in the sediment there is an increase in the concentration of nickel, cobalt, chromium and gold.
"This crater is very well maintained, despite the fact that the glacier is a very effective erosion machine that will quickly eliminate all signs of meteorites. This means that from a geological point of view, the crater is quite young: it is not yet possible to determine its age directly the condition shows that it formed after Greenland began to be covered with ice, so it was younger than 3 million years and even, maybe, it was formed only 12 thousand years ago, "co-author Kurt Kier of the Danish Natural History Museum told the press. University of Copenhagen.
Now scientists plan to more accurately determine the age of the crater to assess the impact of meteorites that shape it on Earth's climate – based on the estimated size of a meteorite, such an impact could be significant at least for the Northern Hemisphere.
There are still around 200 meteorite craters less than six kilometers in diameter, not discovered by scientists, a German geologist came to this conclusion, who built mathematical models based on statistics from meteorite craters on the Moon, but taking into account the process of terrestrial erosion.