Hands-On Activity
Big Idea
Earth's surface is constantly changing. Weathering breaks rocks into smaller pieces, erosion moves those pieces to new places, and deposition leaves them behind. Water, wind, ice, and gravity all work together to shape the land over time.

Materials

• Large baking sheet or tray with edges
• Damp sand
• Small object to prop up one side of the tray (book or block)
• Towel (to catch runoff)
• Pitcher of water
• Watering can or cup with small holes
• 2–3 ice cubes
• Straw

What to Do

Step 1: Build Your Landscape
Prop up one end of the baking sheet to create a gentle slope. Place a towel underneath the lower end to catch any water that runs off.

Pile the damp sand onto the raised half of the tray. Shape it into hills, valleys, or other landforms. Leave the lower half of the tray mostly empty.

Step 2: Create a River
Press two or three ice cubes into flat areas near the top corners of your landscape.
Next, use your finger to make a narrow river channel running from the top of the landscape down to the bottom of the tray.

Step 3: Watch Water at Work
Slowly pour water onto the top of the landscape so it flows through the river channel.

Observe what happens:

• Where does the sand begin to break apart?
• Where is the moving water carrying the sand?
• Where does the sand finally settle?
  
  

Step 4: Test Wind
Use the straw to gently blow across different parts of your sand landscape.
Watch how the moving air breaks apart the sand, carries it away, and deposits it somewhere else.

Step 5: Make It Rain
Use a watering can to create gentle rainfall over your landscape.
Notice how rainfall changes the hills and valleys. Look for more examples of weathering, erosion, and deposition.

Step 6: Observe Ice
Leave the ice cubes in place for several minutes as they begin to melt.
Look closely around the ice. Do you notice any changes to the sand? As glaciers move very slowly in nature, you may not see dramatic changes right away, but melting ice helps demonstrate how glaciers can slowly wear away land and transport sediment over long periods of time.

Reflect

• Where did you see weathering happening?
• Where did erosion occur?
• Where was new sediment deposited?
• Which force changed the landscape the most: flowing water, wind, rain, or ice?
• How do these same processes shape real rivers, mountains, beaches, and valleys?

What's Really Happening (Caregiver Explanation)
This activity models three connected geological processes.

• Weathering is the breaking down of rock or sediment into smaller pieces.
• Erosion is the movement of those pieces by water, wind, ice, or gravity.
• Deposition happens when the moving material is dropped in a new location.

Although this model uses sand instead of rock and speeds up the processes, the same forces shape Earth's surface every day. Rivers carve valleys, wind forms dunes, glaciers reshape mountains, and rainfall gradually changes landscapes over thousands or even millions of years.

Digging Deeper
Explore examples of weathering, erosion, and deposition in your area.

• Can you find a stream with worn, rounded rocks?
• Look for sandbars along a creek or river where sediment has been deposited.
• Find photographs of sand dunes, river deltas, sea cliffs, or glaciers. Which force shaped each landscape?
• How might a landscape change if weathering continued for thousands or millions of years?