What Is Erosion?

Answer:

Wind erosion, Timna Valley, Negev Desert, Israel.

Great canyons and coastal cliffs, rocky crags and awesome caverns — all are products of various kinds of erosion. The term, from the Latin for “gnaw away,” refers to the wearing down of the earth’s surface by natural forces. The agents responsible for this endless sculpting of earth’s outer crust are as varied as wind, water, ice, and even living plants and repeated fluctuations in temperature.

The changes wrought by erosion can take place within minutes, as when the whole side of a mountain gives way in a thundering landslide. Or they can be slow and subtle as the wearing away of the inscription on an ancient tombstone. But whatever the rates or methods of erosion, the result is constant alteration of the lay of the land.