Energy in a Partially Frozen River

When a river freezes over, the water in the middle is sometimes still running. How is the energy in the water different from the frozen water?

Driving Question

• How does the water in a frozen river continue to flow?

Probing Questions

• Why do you think the water keeps running in the middle?
• How cold do you think it has to get for it to freeze in the middle?
• Do you think the size of the river matters?
• How do you think the river water gets its speed to move?
• Do you think thermal energy has anything to do with the river not freezing? 
• Do you think animals can survive under the ice?

Classroom Suggestions

Students could:

• Go for a hike and see a frozen body of water. 
• Try to create a simulation of a frozen body of water. What part of the water freezes first?
• Research temperatures that affect freezing water. 
• Draw a picture of frozen ice particles and compare it to a picture of moving water particles. 

Relevant Related Resources

Science Buddies: Build a River Model: Create a model and then take it outside (if it is winter time) to see how long it takes to freeze. Does water in the middle keep moving? What part of the river freezes first. Include or create a way to have a waterfall so the energy keeps moving the water. Use a hose?
YouTube: Does Moving Water Freeze?: An experiment done with moving water vs. stationary water. Which one freezes first?​​​​​​​
YouTube: The Journey of a River: This short video describes how a river begins. It shows how a river gets its speed and from the beginning of the river to the end.​​​​​​​
YouTube: How Alligators Survive in Frozen Water: *This does not relate to the energy standard, but an anticipated question may be how animals survive under ice. This is a cool video showing how alligators survive during the snow.