American Geophysical Union, Geophysical Research Letters, 15(48), 2021
DOI: 10.1029/2021gl093919
Full text: Unavailable
AbstractCatastrophic meltwater drainage from glacial Lake Agassiz has been hypothesized 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 km3. 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 6–9 month period during the Younger Dryas, though it is unclear whether this was near its beginning.