Ice ages

Science

Definition

Extended periods in Earth's history when global temperatures dropped significantly and large ice sheets expanded across continents. Ice ages are driven by Milankovitch cycles (variations in Earth's orbit), changes in ocean currents, and atmospheric composition. The most recent ice age ended about 11,700 years ago.

Examples

  • The Pleistocene ice age covering much of North America with glaciers up to 3 km thick
  • The Great Lakes formed by glacial erosion and deposition during the last ice age
  • Woolly mammoths and saber-toothed cats adapted to ice age conditions

Related Terms

Climate change Erosion and deposition Ocean currents Atmosphere layers

Study This Concept

Practice ice ages with free review games in these units:

Earth Science Unit 7: Climate and Climate Change