TY - JOUR T1 - Timing and duration of North American glacial lake discharges and the Younger Dryas climate reversal JF - Quaternary Research Y1 - 2011 A1 - Rayburn, John A. A1 - Cronin, Thomas M. A1 - Franzi, David A. A1 - Knuepfer, Peter L. K. A1 - Willard, Debra A. AB - Radiocarbon-dated sediment cores from the Champlain Valley (northeastern USA) contain stratigraphic and micropaleontologic evidence for multiple, high-magnitude, freshwater discharges from North American proglacial lakes to the North Atlantic. Of particular interest are two large, closely spaced outflows that entered the North Atlantic Ocean via the St. Lawrence estuary about 13,200ā€“12,900 cal yr BP, near the beginning of the Younger Dryas cold event. We estimate from varve chronology, sedimentation rates and proglacial lake volumes that the duration of the first outflow was less than 1 yr and its discharge was approximately 0.1 Sv (1 Sverdrup = 106 m3 sāˆ’1). The second outflow lasted about a century with a sustained discharge sufficient to keep the Champlain Sea relatively fresh for its duration. According to climate models, both outflows may have had sufficient discharge, duration and timing to affect meridional ocean circulation and climate. In this report we compare the proglacial lake discharge record in the Champlain and St. Lawrence valleys to paleoclimate records from Greenland Ice cores and Cariaco Basin and discuss the two-step nature of the inception of the Younger Dryas. VL - 75 UR - http://www.sciencedirect.com/science/article/pii/S003358941100024X IS - 3 N1 - id: 2184 JO - Timing and duration of North American glacial lake discharges and the Younger Dryas climate reversal ER -