New study reveals evidence of ice-free times at the center of the Greenland Ice Sheet
A new paper published in the Proceedings of the National Academy of Sciences shows direct evidence of Greenland being ice-free within the last 1.1 million years. This NSF-funded study analyzed sediment drilled through the Greenland Ice Sheet at NSF Summit Station, located at the apex of the ice sheet, in 1993.
This sediment, known as glacial till, was found 3 kilometers below the current ice sheet and was discovered to contain plant fragments, wood, insect parts and fungi. These inclusions, along with dating information provided from analysis, show that within the last 1.1 million years this region was completely covered in tundra vegetation. Instead of ice, this area had a cold, dry environment where snow would last into summer.
These results have implications for the Greenland Ice Sheet today. As the region faces warming climates, scientists now know that the Greenland Ice Sheet has the potential to completely melt.