Alaskan Glaciers Tell A Story Of Deep Time

Rock, once a seafloor of mud, sand, and pebbles, towers into the sky, only to erode away, becoming a new and different seafloor, layered like pages in a book.

Appalachian State University's Dr. Ellen Cowan reads these pages, most recently off the coast of Alaska. They tell the full story of geological changes on the continent, as written by glaciers over millions of years.