How the Great Lakes Were Formed

The Great Lakes look ancient, timeless, permanent. But Lake Superior is younger than the pyramids—and the ground beneath it is still moving today. This is the story of how a two-mile-thick wall of ice carved the largest freshwater system on Earth, and why the continent is still recovering from the deepest bruise it has ever taken. If you enjoy this video, subscribe to Downstream. I test water for a living, and the Great Lakes are the samples I keep coming back to. #GreatLakes #Geology #LakeSuperior #IceAge #Downstream #EarthScience #NaturalHistory Chapters: 00:00 The Illusion of an Ancient Lake 00:54 A Fifth of Earth's Fresh Water 01:14 The Sculptor: Laurentide Ice Sheet 02:18 Carving the Basins 03:29 Filling the Basins: The Glacial Lakes 05:07 Post-Glacial Rebound and Tilting 06:47 Fingerprints of the Ice 08:44 Reading the Landscape