A huge crater has been discovered beneath the ice of Greenland, and is thought to be the result of a meteorite impact millions of years ago. The crater is one of the largest ever discovered, and the first to be found beneath the Greenland ice sheet.
An international team of scientists led by researchers at University of Copenhagen’s Centre for GeoGenetics at the Natural History Museum of Denmark has been studying the crater since July 2015, when it was spotted using ice-penetrating radar data from a NASA mission to log changes to polar ice. The team noted a huge depression beneath the Hiawatha Glacier in northwestern Greenland and decided to investigate further by looking at both radar data and images of the surface ice in the area. The surface ice showed a circular pattern similar to the pattern in the topography map, suggesting that the formation was very old.
The team then flew a research plane over the area to collect a more detailed radar data survey. Joe MacGregor, a NASA glaciologist at Goddard Space Flight Center in Greenbelt, Maryland, was part of the survey and explained: “What we really needed to test our hypothesis [that there was a crater in the area] was a dense and focused radar survey there. The survey exceeded all expectations and imaged the depression in stunning detail: a distinctly circular rim, central uplift, disturbed and undisturbed ice layering, and basal debris — it’s all there.”
The crater measures approximately 19 miles across and is around 1,000 feet deep, meaning that it is around the size of New York City. It formed less than 3 million years ago, likely when an huge meteorite made of iron and measuring more than half a mile wide smashed into the Earth, and is thought to be one of the youngest large impact craters on Earth. The crater remains in surprisingly good condition considering it has been covered in glacier ice which typically erodes traces in rock, suggesting that the impact occurred toward the end of the last ice age.
The data is published in Science Advances and will be followed up with more research into what the consequences of the huge meteorite impact could have been on the climate of Earth and the lifeforms that existed there at the time.
