Coastal permafrost was massively eroded during the Bølling-Allerød warm period

• Main Authors: Nogarotto, A, Noormets, R, Chauhan, T, Mollenhauer, G, Hefter, J, Grotheer, H, Belt, ST, Colleoni, F, Muschitiello, F, Capotondi, L, Pellegrini, C, Tesi, T
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2023
• Subjects: 37 Earth Sciences; 3709 Physical Geography and Environmental Geoscience; 3705 Geology; 13 Climate Action; Arctic; Arctic Ocean; Hanssen; Paige; Svalbard; Alfred Wegener Institute; Climate change; Fram Strait; Ice; permafrost; Sea ice
• Online Access: https://www.repository.cam.ac.uk/handle/1810/357882

Acknowledgements: We thank all the people working in the Marine Geochemistry group at the Alfred Wegener Institute in Bremerhaven for the help and support. The Master and crew of the R/V Helmer Hanssen are gratefully acknowledged for their help during the coring. This study was supported by Ca’ Foscari University of Venice as part of the PhD programme in Polar Sciences. T.T. acknowledges the Italian Research Program in the Arctic (PRA-2019) for financial support (PAST-HEAT project). A.N., T.T. and G.M. acknowledge the Italian-German partnership on “Chronologies for Polar Paleoclimate Archives (PAIGE)” and the funding from the Helmholtz European Partnering. <jats:title>Abstract</jats:title><jats:p>The Bølling-Allerød interstadial (14,700–12,900 years before present), during the last deglaciation, was characterized by rapid warming and sea level rise. Yet, the response of the Arctic terrestrial cryosphere during this abrupt climate change remains thus far elusive. Here we present a multi-proxy analysis of a sediment record from the northern Svalbard continental margin, an area strongly influenced by sea ice export from the Arctic, to elucidate sea level - permafrost erosion connections. We show that permafrost-derived material rich in biospheric carbon became the dominant source of sediments at the onset of the Bølling-Allerød, despite the lack of direct connections with permafrost deposits. Our results suggest that the abrupt temperature and sea level rise triggered massive erosion of coastal ice-rich Yedoma permafrost, possibly from Siberian and Alaskan coasts, followed by long-range sea ice transport towards the Fram Strait and the Arctic Ocean gateway. Overall, we show how coastal permafrost is susceptible to large-scale remobilization in a scenario of rapid climate variability.</jats:p>