Catastrophic drainage from the northwestern outlet of glacial Lake Agassiz during the Younger Dryas

Norris, S. L.; Garcia-Castellanos, D.; Jansen, J. D.; Carling, P. A.; Margold, M.; Woywitka, Robin; Froese, D. G.

Catastrophic drainage from the northwestern outlet of glacial Lake Agassiz during the Younger Dryas

Author

Norris, S. L.

Garcia-Castellanos, D.

Jansen, J. D.

Carling, P. A.

Margold, M.

Woywitka, Robin

Froese, D. G.

Date

2021

Keywords

Lake Agassiz , Younger Dryas , meltwater drainage

Abstract (summary)

Catastrophic meltwater drainage from glacial Lake Agassiz has been hypothesised as a trigger for large-scale ocean circulation change initiating the Younger Dryas cold reversal. Here we quantify the flood discharge that formed the northwestern outlet of Lake Agassiz using a one-dimensional step-backwater model and a zero-dimension gradual-incision model. Applying these two independent models, we estimate a peak discharge range of 1.8-2.5 × 106 m3 s-1 and a flood volume of ~21,000 km. Such a discharge can only be derived from Lake Agassiz rather than one of the two smaller regional glacial lakes: Churchill or Meadow. When coupled with existing ice margin chronologies, these results demonstrate that the northwestern outlet of Lake Agassiz provides a viable link for catastrophic meltwater to drain to the Arctic Ocean over a 5-10 month period during the Younger Dryas, though it is unclear whether this was near its beginning.

Publication Information

Norris, S.L., Garcia-Castellanos, D., Jansen, J.D., Carling, P.A., Margold, M., Woywitka, R., and Froese, D.G. (2021). Catastrophic drainage from the northwestern outlet of glacial Lake Agassiz during the Younger Dryas. Geophysical Research Letters, 48, e2021GL093919. https://doi.org/10.1029/2021GL093919

DOI

https://doi.org/10.1029/2021GL093919

Item Type

Article

Language

English

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