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Its diameter of over 31 km positions it among the 25 largest impact craters on Earth, according to the findings of an international team of researchers formed by experts from Denmark, Germany and the United States. -United.
The crater was formed when a 1 km wide iron meteorite crashed in northern Greenland at a date that has not yet been determined and which has since been buried under the ice of the Hiawatha Glacier.
"The crater is exceptionally well preserved and it is surprising, because the ice of the glacier is an incredibly effective erosive agent that would have quickly eliminated traces of impact," said Professor Kurt H. Kjaer, from Geogenetics Center of the Natural History Museum. from Denmark.
"This means that the crater must be young enough from a geological point of view," he added.
Researchers believe that the crater probably was formed in the Pleistocene, perhaps 12,000 years ago, towards the end of the last ice age, although further studies are needed to dated.
The first signs of the crater's existence date back to July 2015, when researchers inspected a new map of the topography located beneath the Greenland icecap and found the presence of a huge circular undetected depression. before.
They decided to send a research aircraft from the German Alfred Wegener Institute to fly over the Hiawatha Glacier and map the area with the help of a new and powerful ice radar developed by the 39, University of Kansas (United States).
This state-of-the-art radar "has exceeded all expectations and imagined depression with amazing detail," said Joseph MacGregor, a NASA glaciologist who also participated in the survey.
To confirm radar discoveries, new studies on glacier-bottomed rock and sediments driven by a meltwater channel have been performed, detecting the presence of quartz, glass and others. elements related to the impact of the meteorite.
The next step in the investigation is to accurately date the moment of impact and determine if and how it affected the Earth's climate.
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