Synchronized Terrestrial Atmospheric Deglacial Records Around the North Atlantic

• Published in: Science
• Main Authors: Björck, Svante, Kromer, Bernd, Johnsen, Sigfus, Bennike, Ole, Hammarlund, Dan, Lemdahl, Geoffrey, Possnert, Göran, Rasmussen, Tine Lander, Wohlfarth, Barbara, Hammer, Claus Uffe, Spurk, Marco
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1996
• Subjects: ice core; North Atlantic
• Online Access: http://dx.doi.org/10.1126/science.274.5290.1155; https://www.science.org/doi/pdf/10.1126/science.274.5290.1155

On the basis of synchronization of three carbon-14 ( 14 C)-dated lacustrine sequences from Sweden with tree ring and ice core records, the absolute age of the Younger Dryas-Preboreal climatic shift was determined to be 11,450 to 11,390 ± 80 years before the present. A 150-year-long cooling in the early Preboreal, associated with rising Δ 14 C values, is evident in all records and indicates an ocean ventilation change. This cooling is similar to earlier deglacial coolings, and box-model calculations suggest that they all may have been the result of increased freshwater forcing that inhibited the strength of the North Atlantic heat conveyor, although the Younger Dryas may have begun as an anomalous meltwater event.