What’s so great about the Great Lakes? – Cheri Dobbs and Jennifer Gabrys

查看完整課程: http://ed.ted.com/lessons/what-s-so-great-about-the-great-lakes-cheri-dobbs-and-jennifer-gabrys

The North American Great Lakes — Huron, Ontario, 密歇根州, Erie, and Superior — are so big that they border 8 states and contain 23 quadrillion liters of water. They span forest, grassland, and wetland habitats, supporting a region that’s home to 3,500 species. But how did such a vast and unique geological feature come to be? Cheri Dobbs and Jennifer Gabrys takes us all the way back to the Ice Age to find out.

Lesson by Cheri Dobbs and Jennifer Gabrys, TED-Ed 製作的動畫.