Plant, insect, and fungi fossils under the center of Greenland's ice sheet are evidence of ice-free times

• Published in: Proceedings of the National Academy of Sciences - PNAS 2024-08, Vol.121 (33), p.e2407465121
• Main Authors: Bierman, Paul R, Mastro, Halley M, Peteet, Dorothy M, Corbett, Lee B, Steig, Eric J, Halsted, Chris T, Caffee, Marc M, Hidy, Alan J, Balco, Greg, Bennike, Ole, Rock, Barry
• Format: Article
• Language: English
• Subjects: Animals; Arctic Regions; Biological Sciences; Biosphere; cosmogenic; Deglaciation; Ecosystem; Fossils; Fungi; Fungi - classification; GEOSCIENCES; Glacial periods; Glacial till; Greenland; Ice; Ice Cover - microbiology; Ice sheets; Insecta; Insects; interglacial; Nuclides; paleobotany; paleoclimate; Physical Sciences; Plant fossils; Plants - microbiology; Pleistocene; Sea level rise; Tundra
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.2407465121

The persistence and size of the Greenland Ice Sheet (GrIS) through the Pleistocene is uncertain. This is important because reconstructing changes in the GrIS determines its contribution to sea level rise during prior warm climate periods and informs future projections. To understand better the history of Greenland's ice, we analyzed glacial till collected in 1993 from below 3 km of ice at Summit, Greenland. The till contains plant fragments, wood, insect parts, fungi, and cosmogenic nuclides showing that the bed of the GrIS at Summit is a long-lived, stable land surface preserving a record of deposition, exposure, and interglacial ecosystems. Knowing that central Greenland was tundra-covered during the Pleistocene informs the understanding of Arctic biosphere response to deglaciation.