Figure 4. Lake level data for eastern North America, showing conditions wetter on average than today during the late glacial period, then becoming rapidly drier after 10,000 yrs B.P. Maximum aridity occurred at 6,000 years B.P. The return to wetter conditions occurred gradually, with lake levels similar to today by 2,000 years B.P. (after Harrison, 1989).
Last updated on October 6, 2005