1. The Earth’s Interior

2. Write down the things that are in yellow Other 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. IV. Measuring Earthquakes
Seismograph
Device which measures seismic waves
Clicker ?’s 1-9

9. 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

10. Movement (cont.) B. Divergent Boundary 1. two plates are moving apart
 Plate A Plate 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

11. Divergent Boundaries

12. Divergent Boundaries- can observe reverse polarity

13. Movement (cont.) Convergent Boundaries (usually oceanic crust)
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

14. Convergent Boundaries

15. 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)

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

17. Earth’s internal layers SKETCH THIS!

18. 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

19. 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.

20. B. The Mantle
Rocky layer
About 3000 km thick

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

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

23. Upper mantle (cont.) Lithosphere- rigid and brittle Legend
Source:
Lithosphere- rigid and brittle
Legend
Lithosphere &
Crust
Mantle & & &
Asthenosphere
Outer Core
Inner Core

24. Thickness of layers.

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

26. The Crust (cont.) b. Continental crust – below land, less dense
about km thick

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

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

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