A new global ice sheet reconstruction for the past 80 000 years

• Published in: Nature Communications
• Main Authors: Gowan, Evan J., Zhang, Xu, Khosravi, Sara, Rovere, Alessio, Stocchi, Paolo, Hughes, Anna L. C., Gyllencreutz, Richard, Mangerud, Jan, Svendsen, John-Inge, Lohmann, Gerrit
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Ice Sheet
• Online Access: https://research.manchester.ac.uk/en/publications/ba2ebb3a-3d2b-4580-843b-67ad708deb4d; https://doi.org/10.1038/s41467-021-21469-w; https://www.nature.com/articles/s41467-021-21469-w#article-info

The evolution of past global ice sheets is highly uncertain. One example is the missing ice problem during the Last Glacial Maximum (LGM, 26 000-19 000 years before present) – an apparent 8-28 m discrepancy between far-field sea level indicators and modelled sea level from ice sheet reconstructions. In the absence of ice sheet reconstructions, researchers often use marine δ 18 O proxy records to infer ice volume prior to the LGM. We present a global ice sheet reconstruction for the past 80 000 years, called PaleoMIST 1.0, constructed independently of far-field sea level and δ 18 O proxy records. Our reconstruction is compatible with LGM far-field sea-level records without requiring extra ice volume, thus solving the missing ice problem. However, for Marine Isotope Stage 3 (57 000-29 000 years before present) - a pre-LGM period - our reconstruction does not match proxy-based sea level reconstructions, indicating the relationship between marine δ 18 O and sea level may be more complex than assumed.