Glaciers and Geography

Take-Away Points1. The Pleistocene glaciers profoundly affected

world geography and history

2. The Missouri and Ohio Rivers were created because the glaciers blocked existing rivers

3. The Great Lakes were excavated by the glaciers

4. The English Channel was formed because the glaciers blocked existing rivers

5. The ice affected migration of humans into the Americas

Northern Hemisphere Ice Caps

Drainage Diversion,

Missouri River, North Dakota

Mid-Pleistocene Drainage in the Midwest

Pre-Pleistocene Drainage in the Midwest?

Ice Retreat, Canada

Glacial Retreat, Europe

Pluvial Lakes,

Southwest U.S.

Pleistocene Rivers, Indonesia

Excavation of Great Lakes Basins

Occasional Re-Advances

Northeast Tilting of Crust

Lakes in Hudson Bay Basin

Sea Floods Hudson’s Bay

The Present North Sea

Pleistocene Western Europe

Pre-Pleistocene Western Europe

Siberian Super-Rivers?

Coming to America

Take-Away Points• The Pleistocene glaciers profoundly

affected world geography and history

• The Missouri and Ohio Rivers were created because the glaciers blocked existing rivers

• The Great Lakes were excavated by the glaciers

• The English Channel was formed because the glaciers blocked existing rivers

• The ice affected migration of humans into the Americas