The Earth’s I nterior

1. The Earth’s Interior

2. Write down the things that are in yellowOther terms in this PowerPoint are helpful but do not need to be included in your notes.

3. Plate tectonics- describes movement of the crust (theory) • Continental Drift- the continents have drifted from one location to another • Continents used to be in one mass called Pangea(250 mill. Years ago)

4. Earthquakes • Seismic Waves – generated waves traveling through the Earth’s interior • These waves give us clues to the composition of the Earth

6. Types of waves • P-waves (primary waves) • Compress and expand rock • Are the fastest • First waves to register on seismograph

7. Types of waves (cont.) • S-waves (secondary waves) • Vibrate up and down or side to side • 2nd waves to register on a seismograph • S Waves

8. Earthquake 1/6/14

9. IV. Measuring Earthquakes • Seismograph • Device which measures seismic waves • Clicker ?’s 1-9

10. Movement along a fault boundary • Transform-fault boundary – plates are sliding past one another EX. San Andreas fault in California ★ Earthquakes caused by shearing forces

11. Movement (cont.) B. Divergent Boundary 1. two plates are moving apart  Plate APlate B 2.Forms rift valleys - large spreading valleys or 3.Creates sea floor spreading- a rift valley on sea floor 4. Caused by tensional forces

12. Divergent Boundaries

13. Divergent Boundaries- can observe reverse polarity

14. Movement (cont.) • Convergent Boundaries • 2 plates move towards each other Plate APlate B • Leads to subduction- one plate (usually oceanic crust) goes beneath the other (continental crust). • Caused by compressional forces

15. Convergent Boundaries

16. Convergent Boundaries Ex: Andes Mountains in S. America (Still growing because of subduction) 3. ★Common place to find volcanoes Ex: Cascade Range (Mt. St. Helens & Mt. Rainier)

17. Oceanic Crust Subduction Rift Valley (divergent) Quiz Time!- word bank (some > 1)Transform BoundaryConvergent BoundaryDivergent BoundaryContinental Crust 6. Crust type 7. Crust type 4. 2. 1. 3. 8. 5.

18. Earth’s internal layers • Geologists did research with seismic waves • Concluded that the Earth’s interior is layered.

19. Earth’s internal layersSKETCH THIS!

20. Earth’s internal layers A. Core- 1. Composed mostly of iron and nickel 2. Inner Core • very hot • solid Fe & Ni due to high pressure of the Earth

21. The Core (continued) • 3. Outer Core • less pressure from the earth • liquid Fe & Ni • Flow in the outer core generates an electric current that powers the Earth’s magnetic field.

22. B. The Mantle • Rocky layer • About 3000 km thick

23. Mantle (cont.) a. Lower mantle b. Upper mantle – two sections

24. 1. Asthenosphere - behaves in a semi-fluid manner Upper mantle (cont.)

25. Source:http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/tectonics/earth_structure.jpgSource:http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/tectonics/earth_structure.jpg Upper mantle (cont.) Lithosphere- rigid and brittle Legend Lithosphere & Crust Mantle & & & Asthenosphere Outer Core Inner Core

26. Thickness of layers.

27. C. The Crust • Uppermost portion of the lithosphere • Two types of crust a. Oceanic crust – below ocean, dense about 10 km thick

28. The Crust (cont.) b. Continental crust – below land, less dense about 20-60 km thick

29. Evidence that supports the theory of Continental Drift 1. Geologic (rock) 2. Biologic (life) 3. Climatological (past weather) 4. Continental Shelves fit together well

30. Tectonic Plates moving sections of the lithosphere on which continents lie

31. Major Tectonic Plates Clicker ?’s 1-9 (Continental Drift and Faults)