EROSION

Erosion is constantly changing, creating, and erasing features on Earth's surface.

Erosion happens through wind, water, and glaciers.

Erosion can take hundreds of thousands - even millions - of years.

Rainwater can change a hillside.

Wind can slowly scrape the rocks off a mountain.

Millions of tons of rock and gravel can be picked up and moved by icy glaciers.

Strong winds and large waves from hurricanes can make beaches disappear.

Floods can wash away soil from hill sides and change the path rivers follow.

Soil is made from weathered rocks.

Erosion helps move soil from one place to another.

Wind erosion deposited silt on the Great Plains. Silt helps make excellent soil for planting crops.

Water erosion carries sediments to river deltas, creating rich farmland.

People have sped up erosion in some places.

Farming can cause soil erosion because of poor farming methods.

Cutting down trees cause erosion.

Tree roots help hold soil in place, but without trees, rainwater can wash soil away.

Overgrazing of land by cattle can even cause erosion.

Exposed soil can get carried away by the wind.

Rich soil takes thousands of years to form.

Soil is being lost faster than nature can replace it.