Earth Events

Wind and water are two forces that constantly change and re-shape Earth’s surface over time. In this lesson, students are introduced to weathering and erosion with an experiment that compares the amount of erosion that takes place when the intensity of wind blowing and water flowing changes. Students then examine different events that change Earth’s surface, classifying the changes as fast or slow.  

• Earth’s surface is made up of different materials.  
• The materials that make up Earth’s surface change over time. To change means to make something different from what it is now.
• Weathering happens when the Earth materials that make up the land are broken down into smaller pieces, and it can be caused by different things, including wind and water.
• Weathered Earth materials are often eroded. Erosion happens when weathered pieces of Earth materials are moved to new places.  
• The amount of weathering and erosion that takes place changes depending on various factors, including how much wind or water is moving and how fast it is moving.
• We can compare the changes to Earth’s surface based on how long it takes the change to happen.

• What materials make up Earth’s surface? Where have you seen some of these different materials?
• How can you describe the properties of Earth materials?
• What causes rocks and other Earth materials to become weathered?
• How is erosion different from weathering? Why do weathering and erosion often happen at the same time?
• What causes small pieces of rock, soil, or sand to move to new places through erosion?
• What will happen to Earth materials when a large river flows over them compared to a small river?  
• Do all changes to Earth’s surface take place quickly?
• How are slow changes different from quick changes?  
  
  

Misconception: Erosion always happens quickly.

Fact: Erosion can occur quickly, but it often happens very slowly, over hundreds, thousands, or millions of years.

Misconception: Erosion is always “bad.”

Fact: Erosion isn’t “bad” or “good.” Many landforms are created by the deposition of eroded Earth materials.

Misconception: Earth’s surface, including its rocks, doesn’t change.

Fact: Earth’s surface is constantly changing. Some of these changes happen quickly, and other changes happen very slowly.

Change: to make something different from what it is know

Engineer: anyone who uses scientific knowledge and mathematics to solve a problem by creating new technologies

Erosion: the movement of small pieces of rock, soil, and sand from one place to another by wind or water

Prototype:  a smaller version of what will be engineered

Weathering:   the breakdown of Earth materials (such as rocks, sand, and soil) into smaller pieces; can be caused by wind, water, or living things

A Changing Waterfall

A long time ago, Niagara Falls looked very different. It used to be made up of one waterfall. It also was in a different place. It has moved backwards over time. These changes happened because water changes Earth’s surface as it moves over it. To change means to make something different from what it is now.

Water Changes the Land

Earth’s surface is made up of different materials. For example, the land is made up of soil, rocks, and sand. As water moves over the land, it changes these Earth materials.

Weathering happens when Earth materials are broken down into smaller pieces. Water weathers the land as it moves over it. Wind, plants, and animals also weather Earth materials.

Erosion happens when these weathered pieces of Earth materials are moved to new places. For example, moving water carries with it weathered Earth materials. This is erosion. Wind can also erode Earth materials. As the wind blows, it carries with it small pieces of weathered Earth materials.

This lesson has one experiment and one investigation. In the first part, students collaboratively conduct an experiment to answer the question: “How does the amount of water that flows and wind that blows on a hillside affect the shape of the hillside?” In the investigation, students ask questions about the relative timescales of different events that change Earth’s surface. In the experiment, students create a visual model (scientific diagram) of their experiment-in-progress. Students use the model to visualize how the materials will be used in their wind and water experiment and to communicate their experiment to others. They then create a physical model to compare how sand on a hillside moves when different amounts of wind and water move across it.