Megafloods and large rivers

A great many of Earth's major rivers experienced the influence of megafloods associated with the margins of large late Pleistocene ice sheets. Connected systems and large-scale pathways of glacial flood spillways were associated with all the great continental ice sheets, and those of the Eurasian ice sheets may have temporarily constituted the largest terrestrial river system. Up until the early nineteenth century, considerable progress was being made in understanding the role of cataclysmic flooding for the geological evolution of river valleys. Continental ice sheets that form during epochs of glaciation exert immense influences on water drainage across the land. The whole system of Asian spillways and megalakes temporarily constituted Earth's longest river, over 8000 km in length. Thus, the late Quaternary glacial phase of the northern hemisphere was marked by widespread magafloods and megarivers.