How the Earth Was Made - Great Lakes

Seizoen: 1 - Aflevering: 7 / 7 - Eerst uitgezonden: 24 maart 2009 - Episode ID: 406661

Scientists seek clues to the formation of North America's Great Lakes, the largest expanse of fresh water on the planet; delving into an underground salt mine; investigating a fossilized coral reef; diving to the bottom of Lake Superior.