Opening of glacial Lake Agassiz’s eastern outlets by the start of the Younger Dryas cold period

Research Article| January 04, 2018 Opening of glacial Lake Agassiz's eastern outlets by the start of the Younger Dryas cold period David J. Leydet; David J. Leydet * 1Department of Geography and Environmental Engineering, U.S. Military Academy, West Point, New York 10996, USA2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA *E-mail: david.leydet@usma.edu Search for other works by this author on: GSW Google Scholar Anders E. Carlson; Anders E. Carlson 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA Search for other works by this author on: GSW Google Scholar James T. Teller; James T. Teller 3Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada Search for other works by this author on: GSW Google Scholar Andrew Breckenridge; Andrew Breckenridge 4Natural Sciences Department, University of Wisconsin–Superior, Superior, Wisconsin 54880, USA Search for other works by this author on: GSW Google Scholar Aaron M. Barth; Aaron M. Barth 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA5Department of Geoscience, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA Search for other works by this author on: GSW Google Scholar David J. Ullman; David J. Ullman 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA6Northland College, Ashland, Wisconsin 54806, USA Search for other works by this author on: GSW Google Scholar Gaylen Sinclair; Gaylen Sinclair 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA Search for other works by this author on: GSW Google Scholar Glenn A. Milne; Glenn A. Milne 7Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada Search for other works by this author on: GSW Google Scholar Joshua K. Cuzzone; Joshua K. Cuzzone 8Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA Search for other works by this author on: GSW Google Scholar Marc W. Caffee Marc W. Caffee 9Department of Physics and Astronomy, and Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana 47907, USA Search for other works by this author on: GSW Google Scholar Author and Article Information David J. Leydet * 1Department of Geography and Environmental Engineering, U.S. Military Academy, West Point, New York 10996, USA2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA Anders E. Carlson 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA James T. Teller 3Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada Andrew Breckenridge 4Natural Sciences Department, University of Wisconsin–Superior, Superior, Wisconsin 54880, USA Aaron M. Barth 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA5Department of Geoscience, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA David J. Ullman 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA6Northland College, Ashland, Wisconsin 54806, USA Gaylen Sinclair 2College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, Oregon 97331, USA Glenn A. Milne 7Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada Joshua K. Cuzzone 8Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA Marc W. Caffee 9Department of Physics and Astronomy, and Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana 47907, USA *E-mail: david.leydet@usma.edu Publisher: Geological Society of America Received: 07 Jul 2017 Revision Received: 20 Nov 2017 Accepted: 21 Nov 2017 First Online: 04 Jan 2018 Online Issn: 1943-2682 Print Issn: 0091-7613 © 2018 Geological Society of America Geology (2018) 46 (2): 155–158. https://doi.org/10.1130/G39501.1 Article history Received: 07 Jul 2017 Revision Received: 20 Nov 2017 Accepted: 21 Nov 2017 First Online: 04 Jan 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation David J. Leydet, Anders E. Carlson, James T. Teller, Andrew Breckenridge, Aaron M. Barth, David J. Ullman, Gaylen Sinclair, Glenn A. Milne, Joshua K. Cuzzone, Marc W. Caffee; Opening of glacial Lake Agassiz's eastern outlets by the start of the Younger Dryas cold period. Geology 2018;; 46 (2): 155–158. doi: https://doi.org/10.1130/G39501.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The Younger Dryas (12.9 ± 0.1 to 11.7 ± 0.1 ka) was a return to cold conditions in the Northern Hemisphere during the last deglaciation. This climatic event was hypothesized to have been caused by a change in glacial Lake Agassiz (north-central North America) overflow from its routing to the Gulf of Mexico to an easterly route to the North Atlantic due to Laurentide ice-sheet retreat from the Lake Superior basin, which caused a reduction in Atlantic meridional overturning circulation. Alternative models argue that Lake Agassiz triggered the Younger Dryas via northwestward routing to the Arctic Ocean. We present new 10Be surface exposure ages that directly date ice retreat from eastern Lake Agassiz outlets and show that the area was ice free at the onset of the Younger Dryas. The southernmost eastern channels opened at 14.0 ± 0.4 ka and 13.6 ± 0.2 ka, but an ice-free route through the Lake Superior basin only opened after 13.5 ± 0.5 ka. The main eastern channel to the eastern Great Lakes and North Atlantic opened at 13.0 ± 0.1 ka to 12.7 ± 0.3 ka. This channel opening was concurrent with decreased runoff to the Gulf of Mexico and increased runoff through the lower Great Lakes to the Gulf of St. Lawrence and North Atlantic. Gulf of St. Lawrence runoff records and isostatic-rebound modeling suggest eastern outlet abandonment at ca. 12.2 ka, with possible northwestward routing of runoff. Our results confirm that Lake Agassiz overflow could have been routed eastward to the North Atlantic at the Younger Dryas onset and caused the canonical abrupt climate change event. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.