1. Weathering and Erosion

2. Have you ever been to the arch?

3. What is at the base of the arches?

4. Can you see how this rock started out as sand?

5. Blowing sand acts like sandpaper.

6. Wind can erode rocks and cause sediment.
Erosion: the process that breaks down a rock into smaller pieces Sediment: small pieces of rock that has been eroded

7. Water can cause erosion, too.

8. What are some other ways stuff can get eroded?

9. Freeze-Thaw Cycle

10. Freezing and Thawing (ice wedging)
Water seeps into cracks in the rock and freezes at low temperatures.
Water expands when it freezes.
When these steps are repeated over and over, the cracks expand until pieces break off.

12. Animals and humans can cause erosion…

13. It takes energy to move sediment and erode stuff…where does that energy come from?
Turn and talk…

14. Your ideas…

15. The energy comes from the SUN!!

16. How does the sun cause weather?
The earth is round, not flat, so the sun’s rays don’t fall evenly on the land and oceans.
The equator gets more of the direct radiation.
Polar regions are at an angle so they don’t get much sunlight during the winter, causing colder temperatures.

17. Uneven heating of the earth causes convection currents.