Spatial variations in lake levels since the last glacial maximum in the Americas north of the equator

The temporal sequence of hydrological fluctuations has been reconstructed using information from the Oxford Lake-Level Data Bank. This data base contains records of geochronometrically-dated fluctuations in lake level from basins which have been closed during part or all of the Late Quaternary. Maps of lake status, an index of relative depth, the presented for the period 18 000-0yr BP. High and intermediate lake levels were recorded between 32-40^oN at the Last Glacial Maximum (18 000yr BP). The situation persisted until about 14 000yr BP. Many of the features of the present day lake-level pattern were established by 3000yr BP. These patterns reflect changes in air mass trajectories over the continent and, hence, displacements in major features of the general circulation. -from Authors