1. Internal Forces that Shape the Earth (Plate Actions)

2. Plate Tectonics Continental Drift – plates move slowly across upper mantle “Pangaea” – supercontinent existed 250 million years ago

4. Divergent Boundary Plates separate / spread apart

5. A. Mid ocean ridge Two ocean plates separate

6. B. Rift Valley Two land plates separate

7. Convergent Boundaries Plates collide

8. A. Mountains Two land plates collide

9. B. Island Chains Two ocean plates collide

10. C.Ocean Trench and Mountains Land and ocean plates collide

11. Transform Boundary Two plates slide against each other

12. A. Fault

13. V. Earthquakes and volcanoes form along plate boundaries

14. External Forces that Shape the Earth

15. Weathering The breaking down of rock into sediment

16. Physical Weathering

17. Chemical Weathering

18. Erosion The carrying away of sediment

19. A. Water is the greatest agent of erosion

20. B. Wind

21. C. Glaciers / Ice

22. Landforms 1.Created by tectonic processes 1.Mountains, valleys 2.Created by erosion 1.Plateau, plains 3.Created by sediment deposition 1.Sand dune, floodplain

23. Most regions have a combination of all three types Example: Mountain range formed by tectonic activity. Erosion forms deep valleys between the mountains. Sediment eroded from the mountains is deposited at the mountains’ bases. Creates an alluvial fan.

24. Alluvial fan: fan-shaped deposit of mud and gravel often found at the base of mountains. Stream erodes the sediment in the alluvial fan and carries them to a river mouth. Sediment moves into the ocean and sinks, or it may accumulate and build a delta.