Illustration: NASA/Science

DTU contributes to mapping of unique meteorite crater in Greenland

Geology Polar research Climate change
An international team of researchers has discovered a giant meteorite crater—with a diameter of 31 km—buried deep under the inland ice in Greenland.

Thousands of years ago, a heavy iron meteorite smashed into what is today Northern Greenland, leaving a giant crater. This discovery has been made by new international research, headed by the Centre for GeoGenetics at the Natural History Museum of Denmark, University of Copenhagen (UCPH), to which DTU Space has contributed.

The discovery is unique. It is the first time that a crater of this size has been found under one of the Earth’s ice caps. The discovery has just been published in the prestigious scientific journal Science/Science Advances.

The meteorite crater found under the Hiawatha Glacier in Greenland measures over 31 km in diameter and is roughly of the same size as the Danish island of Bornholm, making it one of the 25 largest craters discovered on the Earth.

Young crater
The crater is unusually well preserved, which means that it must be a young crater—in geological terms—as the ice would otherwise have eroded the traces of the impact.

"It's a great side benefit to our climate research to discover a crater from a giant iron meteorite."
Shfaqat Abbas Khan, associate professor at DTU Space

A precise dating has so far not been possible. However, the researchers believe that the crater is less than three million years old, and—according to Professor Kurt H. Kjær from the Centre for GeoGenetics at UCPH—it may already have been formed about 12,000 years ago.

Studies of the shape and size of the crater, mapping of tectonic structures in the geology at the foot of the glazier, and analysis of sediments—washed from the bottom of the crater via a meltwater river—show that the crater was formed by the impact of a giant iron meteorite. The meteorite may have been up to 1.5 km in diameter. And this is interesting, for example in relation to the Earth’s climate history.

“We know that the temperature on the Earth suddenly dropped 12,900 years ago, and this cold period lasted for about 1,300 years. One of the possible explanations of this sudden cold is that the Earth was hit by a meteorite. The question is whether it’s this meteorite we have now found. At any rate, it’s big enough to have potentially had a significant impact on life on the Earth,” says Shfaqat Abbas Khan—Associate Professor and researcher at DTU Space—who was among the many partners in the large-scale research project.

Side benefit of climate research
Shfaqat Abbas Khan also explains that the new discovery of the giant crater near the Hiawatha Glacier is—in effect—a by-product of studies conducted for a completely different purpose.

“One of the reasons that we’ve found the crater precisely now is the many surveying campaigns with airplanes aimed at mapping the topography under the ice sheet,” he says.

“We’re basically not looking for craters, but collecting data for models that can provide information about the ice melting of the future, because this is important to the climate of the future. But it's a great side benefit to our climate research to discover a crater from a giant iron meteorite.”