Introduction to Erosion

​Introduction to Erosion

By Katherine Felton

Learning Objectives

By the end of this lesson students will be able to:

• Define erosion and differentiate it from weathering.

• Identify the four main agents of erosion (water, wind, ice, and gravity).

• Describe how erosion is a destructive process that shapes landforms.

• Collaborate with peers to model and explain a form of erosion.

Look at this image of the Ohio River Valley. We know from our last unit that weathering breaks down rock, but weathering alone doesn't create a huge valley like this. The broken rock pieces have to be moved away.

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​Guiding Question

Open Ended

What force or process do you think is powerful enough to carry away trillions of tons of rock and soil to carve out this valley over millions of years?

Think-Pair-Share

Erosion is the process of moving weathered rock and soil from one place to another..

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What is Erosion?

"If weathering is the hammer that breaks the rock, erosion is the truck that hauls the pieces away."

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Weathering vs. Erosion

Water: Rivers, waves, floods.

Wind: Dust storms, sand dunes. Explain that wind can only move smaller particles.

​The Four Agents of Erosion...

Ice: Glaciers carving through mountains, leaving behind U-shaped valleys.

Gravity: Landslides, rockfalls, mudslides (mass movement).

​The Four Agents of Erosion...

Open Ended

What's the key difference between weathering and erosion?

Open Ended

Could erosion happen without weathering?

Quick Review!

Multiple Choice

Plant root grow in a rock and cause it to split.

• Weathering

• Erosion

Multiple Choice

A fast-moving river carries rocks downstream.

• Weathering

• Erosion

Multiple Choice

Wind blowing sand from one location to another.

• Weathering

• Erosion

Multiple Choice

Rainwater enters the cracks of a rock, freeze, and causes the rock to break apart.

• Weathering

• Erosion

Multiple Choice

The soil from a hillside is washed away by rain.

• Weathering

• Erosion

Multiple Choice

Fast running water causes rocks to hit one another breaking them into smaller rocks.

• Weathering

• Erosion

Multiple Choice

A mudslide flowing down a steep hill.

• Weathering

• Erosion

Multiple Choice

Erosion is the process by which water, ice, wind, or gravity move pieces of rock and soil.

• TRUE

• FALSE