1. Things that BUILD UP and TEAR DOWN the Earth…

2. Constructive Forces
the process of building up the Earth’s surface

3. Destructive Forces
the process of breaking down the Earth’s surface

4. Sand Dunes
a ridge of sand created by the wind

5. Delta
the area where a river empties out into a larger body of water

6. Cave
a hollow or natural passage under or into the Earth

7. Canyon
a deep valley with steep sides, often has a stream at the bottom

8. Levee
a barrier built to keep the flow of water out

9. Glacier
a slow moving mass of ice