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. Earthquake 1/5/13

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 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

12. Divergent Boundaries

13. Divergent Boundaries- can observe reverse polarity

14. Movement (cont.) Convergent Boundaries Leads to subduction- one plate
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. Rift Valley (divergent)
Quiz Time!- word bank (some > 1) Transform Boundary Convergent Boundary Divergent Boundary Continental Crust
Oceanic Crust
Subduction
Rift Valley (divergent)
6. Crust type
7. Crust type 2. 4. 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 layers SKETCH 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. Upper mantle (cont.)
1. Asthenosphere - behaves in a semi-fluid manner

25. Upper mantle (cont.) Lithosphere- rigid and brittle Legend
Source:
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 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)