This follows the finding, announced in November 2018, of a 31-kilometre- (19-mile)-wide crater beneath Hiawatha Glacier – the first meteorite impact crater ever discovered under Earth’s ice sheets. Though the newly found impact sites in northwest Greenland are only 183 kilometre (114 miles) apart, at present they do not appear to have formed at the same time according to the new study, published in American Geophysical Union’s journal Geophysical Research Letters.
If the second crater, which has a width of over 35 kilometres (22 miles), is ultimately confirmed as the result of a meteorite impact, it will be the 22nd largest impact crater found on Earth.
“We’ve surveyed the Earth in many different ways, from land, air and space – it’s exciting that discoveries like these are still possible,” says Joe MacGregor, a glaciologist with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, United States, who participated in both findings.
Before the discovery of the Hiawatha impact crater, scientists generally assumed that most evidence of past impacts in Greenland and Antarctica would have been wiped away by unrelenting erosion by the overlying ice. Following the finding of that first crater, MacGregor checked topographic maps of the rock beneath Greenland’s ice ...