The well-preserved crater could have been created 12,000 years ago. Radar and soil samples now confirm the impact.
Now researchers have the certainty: The 2015 discovered in northern Greenland outlines of a crater actually come from a meteorite impact. The tracks are under a thick layer of ice. Radar and soil samples confirmed the assumption.
Scientists have discovered a 31-kilometer impact crater below the Hiawatha Glacier. With an area larger than Paris, it is one of the 25 largest known impact craters on earth, reported in the journal Science Advances. Never before has such a crater been discovered under one of the continental ice sheets of the earth.
At the site, once a kilometer-wide iron meteorite must have hit, said the researchers around Kurt Kjær from the Center for GeoGenetics at the Natural History Museum of the University of Copenhagen. A dating of under one kilometer of ice lying, exceptionally well preserved crater was previously not visible, possibly its about 12,000 years ago at the end of the last glaciation. The timing of the impact was essential to understanding how the life on Earth had an impact. Large meteorite impacts can have a lasting effect on the climate.
“The new radar system of the research aircraft of the Alfred Wegener Institute was exactly the type of instrument we needed for the measurements,” says glaciologist Olaf Eisen. In addition, the researchers collected samples of sediments and mapped the tectonic structures in the rock at the foot of the glacier. “Part of the quartz sand washed out of the crater had just those deformation features that point to a violent impact,” says Nicolaj Larsen from Aarhus University.