Rapid northern hemisphere ice sheet melting during the penultimate deglaciation

• Published in: Nature Communications
• Main Authors: Stoll, Heather M, Cacho, Isabel, Gasson, Edward, Sliwinski, Jakub, Kost, Oliver, Moreno, Ana, Iglesias, Miguel, Torner, Judit, Perez-Mejias, Carlos, Haghipour, Negar, Cheng, Hai, Edwards, R Lawrence
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Ice Sheet; North Atlantic
• Online Access: https://risweb.st-andrews.ac.uk/portal/en/researchoutput/rapid-northern-hemisphere-ice-sheet-melting-during-the-penultimate-deglaciation(8d951113-5711-4d94-8f8b-5f8eb5140ff7).html; https://doi.org/10.1038/s41467-022-31619-3; https://research-repository.st-andrews.ac.uk/bitstream/10023/25631/1/Stoll_2022_NC_Rapid_northern_hemisphere_CC.pdf

The rate and consequences of future high latitude ice sheet retreat remain a major concern given ongoing anthropogenic warming. Here, new precisely dated stalagmite data from NW Iberia provide the first direct, high-resolution records of periods of rapid melting of Northern Hemisphere ice sheets during the penultimate deglaciation. These records reveal the penultimate deglaciation initiated with rapid century-scale meltwater pulses which subsequently trigger abrupt coolings of air temperature in NW Iberia consistent with freshwater-induced AMOC slowdowns. The first of these AMOC slowdowns, 600-year duration, was shorter than Heinrich 1 of the last deglaciation. Although similar insolation forcing initiated the last two deglaciations, the more rapid and sustained rate of freshening in the eastern North Atlantic penultimate deglaciation likely reflects a larger volume of ice stored in the marine-based Eurasian Ice sheet during the penultimate glacial in contrast to the land-based ice sheet on North America as during the last glacial.