Abrupt drainage cycles of the Fennoscandian Ice Sheet

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Soulet, Guillaume, Menot, Guillemette, Bayon, Germain, Rostek, Frauke, Ponzevera, Emmanuel, Toucanne, Samuel, Lericolais, Gilles, Bard, Edouard
• Other Authors: Geo-Ocean (GEO-OCEAN), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Géochimie et Métallogénie (LGM), Géosciences Marines (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire Environnements Sédimentaires (LES), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [SDU]Sciences of the Universe [physics]; [SDV]Life Sciences [q-bio]; Fennoscandian; Ice Sheet
• Online Access: https://hal.science/hal-04499348; https://doi.org/10.1073/pnas.1214676110

Continental ice sheets are a key component of the Earth’s climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former ice-sheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate–lake–FIS system, linked to changes in the availability of subglacial water, led to abrupt drainage cycles of the FIS into the BS watershed. This phenomenon raised the BS water level by ∼100 m until the sill of the Bosphorus Strait was reached, flooding the vast northwestern BS shelf and deeply affecting the hydrology and circulation of the BS and, probably, of the Marmara and Aegean Seas.