North America

Nearly all lakes in North America reflect the balance of precipitation and evaporation through changes in lake level. In this way, lake levels track long-term changes in climate, and lake-level reconstructions provide valuable information about hydroclimate variability over centennial and longer time scales. In Alaska and the Yukon and in the east from Quebec to Florida, many lakes reached their lowest levels before 9. cal. ka BP and rose in the mid-Holocene, while in the mid-continent, between 8 and 4. cal. ka BP, many lakes from the Great Basin to the Great Lakes were low, and have since risen considerably. The long-term dynamics of ice-sheet growth and retreat and the seasonality of insolation are often cited as the primary drivers of coherent patterns in the regional histories.