• DOI:10.1038/s41561-018-0169-6
• Corpus ID: 133852610

Deglacial floods in the Beaufort Sea preceded Younger Dryas cooling

@article{Keigwin2018DeglacialFI,
  title={Deglacial floods in the Beaufort Sea preceded Younger Dryas cooling},
  author={Lloyd D. Keigwin and Shannon A. Klotsko and Ning Zhao and Brendan T. Reilly and Liviu Giosan and Neal Driscoll},
  journal={Nature Geoscience},
  year={2018},
  volume={11},
  pages={599-604}
}

• L. Keigwin, S. Klotsko, +3 authors N. Driscoll
• Published 9 July 2018
• Geology
• Nature Geoscience

A period of cooling about 13,000 years ago interrupted about 2,000 years of deglacial warming. Known as the Younger Dryas (YD), the event is thought to have resulted from a slowdown of the Atlantic meridional overturning circulation in response to a sudden flood of Laurentide Ice Sheet meltwater that reached the Nordic Seas. Oxygen isotope evidence for a local source of meltwater to the open western North Atlantic from the Gulf of St Lawrence has been lacking. Here we report that the eastern Beaufort Sea contains the long-sought signal of 18O-depleted water. Beginning at ~12.94 ± 0.15 thousand years ago, oxygen isotopes in the planktonic foraminifera from two sediment cores as well as sediment and seismic data indicate a flood of meltwater, ice and sediment to the Arctic via the Mackenzie River that lasted about 700 years. The minimum in the oxygen isotope ratios lasted ~130 years. We suggest that the floodwater travelled north along the Canadian Archipelago and then through the Fram Strait to the Nordic Seas, where freshening and freezing near sites of deep-water formation would have suppressed convection and caused the YD cooling by reducing the meridional overturning.A 700-year-long flood of glacial meltwater, ice and sediment from the Mackenzie River preceded the freshening of the Beaufort Sea prior to the Younger Dryas climate event, according to sediment analyses.