Controls, history, outbursts, and impact of large late-Quaternary proglacial lakes in North America

Abstract

This chapter provides an overview of the controls on proglacial lake systems and presents a capsule of the current understanding of the history and interrelation of the largest proglacial lakes in North America, specifically those that fringed the Laurentide Ice Sheet (LIS). The chapter also explores some new developments in the understanding of the relationship of large proglacial lakes to global-scale changes in oceans and climate. Proglacial lakes, along the LIS in North America, cover a total of more than 2 million km 2 , and in some areas, such as the Great Lakes basins, glaciation only leads to the expansion and contraction of the existing bodies of water. The first lakes to form along the LIS margin during its retreat are in the southern parts of the Great Lakes' basins. The abrupt transfers of water from one lake basin to another have significant hydrological impacts on lakes, rivers, and oceans as well as on climate. There is an increasing recognition of the role that proglacial lakes played in influencing climate and in bringing about climate change. One aspect relates to the thermal capacity of water, which makes a lake slow to respond to seasonal warming and cooling; lake temperatures fluctuate less than do those on land and tend to moderate climate and increase cloudiness and precipitation in the region around it; therefore, ecosystems around large lakes tend to be different.