1. Earth’s Structure
and Plate Tectonics

2. Structure of the Earth
Core- center of the earth, made up of iron and nickel
Outer core is liquid and inner core is solid
Mantle- several layers, contains most of the earth’s mass,
Magma- molten rock, forms in the mantle
Crust- thin layer of rock at the earth’s surface, miles thick

4. Earth Earth is made up of 4 spheres: Lithosphere Atmosphere
Hydrosphere
Biosphere

5. Atmosphere The layer of gases surrounding Earth Oxygen we breathe
Protects the Earth
Medium for weather and climate

6. Lithosphere Forms the seafloor 30-90 miles thick
Solid rock portion of Earth
Crust and Upper Mantle
Forms the seafloor
30-90 miles thick

7. Hydrosphere Water elements of Earth
Ocean, seas, rivers, lakes, and water in the atmosphere

8. Biosphere Part of Earth where plants and animals live
Made up of Lithosphere, Atmosphere, and Hydrosphere

9. Atmosphere
Hydrosphere
Lithosphere

10. Plate Tectonics
Plate tectonics- enormous moving pieces of the earth’s lithosphere
Rock in the asthenosphere (upper portion of the mantle) is heated and rises toward the lithosphere, cools and circulates downward

12. Divergent- plates move apart, spreading horizontally
Ex. Saudi Arabia and Egypt (make the Red Sea even wider)

13. Divergence – Moving Apart
Rift Valley – if the land is above water
Sea Floor Spreading – when the land is below water

14. Great Rift Valley in Africa
(spreading apart)
hamroush/images/Geol...

15. Convergent- plates collide, causing either one plate to dive under the other or the edges of both plates to crumble
Ex. plate in which India is located is crashing against the Asia plate causing the Himalayas

16. Subduction- the heavier plate will sink and the lighter will rise to the surface

17. Convergence – Moving Together
Trenches
Mountains
Structural Mountains
Volcanic Mountains

18. Andes Mountains
redtailcanyon.com/items/6503.aspx

19. Transform- plates slide past one another
Ex. San Andreas fault in CA
If the rock isn’t flexible, it will cause a fault

21. San Andreas Fault in California
geography.sierra.cc.ca.us/ booth/California/1_...

22. Continental Drift 65 million years ago, Pangaea split apart
Because the sea floor was expanding (newer fossils were found in the middle of the ocean