An international team of researchers that includes a NASA glaciologist has discovered a 19-mile-wide meteorite impact crater hiding beneath more than half a mile of ice in northwest Greenland. This is the first impact crater of any size ever found under the polar ice sheets.
The group, led by researchers from the Centre for GeoGenetics at the Natural History Museum of Denmark, University of Copenhagen, worked for the past three years to verify their discovery, which was initially made in 2015 using NASA data. The researchers first spotted the crater in July 2015, while they were inspecting a new map of the topography beneath Greenland’s ice sheet that used ice-penetrating radar data primarily from NASA’s Operation IceBridge — a multi-year airborne mission to track changes in polar ice — and earlier NASA airborne missions in Greenland. The scientists noticed an enormous, previously unexamined circular depression under Hiawatha Glacier, sitting at the very edge of the ice sheet in northwestern Greenland.
Their finding is described in a study published on Nov. 14 in the journal Science Advances. The crater is roughly 1,000 feet deep and more than 19 miles in diameter, encompassing an area slightly larger than that comprised inside the Capital Beltway around Washington, D.C. Its dimensions place it among the 25 largest impact craters on Earth.
The crater formed when an iron meteorite more than half a mile wide smashed into northwest Greenland – but the timing of when the event happened remains a key question and one the researchers want to answer next. The authors put the range between less than three million years ago and as recently as less than 13,000 years ago. The resulting depression has since been covered by ice.
A narrated video outlines the discovery and includes data visualizations which can be found here: https://svs.gsfc.nasa.gov/4572