Evidence of the Ice Ages

  • Exhibition Text

    • For the last two million years, the climate of our planet has been mostly cold, with great ice caps covering much of Europe, Asia, and North America. Land surface temperatures were 5 to 15 degrees Centigrade cooler than today. The glacial periods were interrupted by warm periods, but the warm periods make up only about 10 percent of the last million years. The mild, stable conditions of the last 10,000 years, during which human civilization has flourished, are not typical of the last two million years.

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  • For Educators

    • Topic: Earth Science

      Subtopic: Geologic Time

      Keywords: Glacial epoch, Paleoclimatology, Global temperature changes

      Audience: General

In This Section

Glacial striations

Glacial striations

The surface scratches on this sample, from an outcrop of granite gneiss, are called glacial striations.

Windblown dust

Windblown dust

This sample of windblown dust, or loess, was deposited 23,000 years ago, at the height of the last glaciation, where sediments were washing out of glaciers.