1. Plate Tectonics

2. Views of the Earth

3. View of Earth’s Interior

4. A. The Earth in Cross Section
I. There are 4 major zones that make up the Earth:
A : Outer, thinnest layer of the Earth. There are two types: :
-Thickness:
-Composition:
-Density: :
Crust
Oceanic
Up to 5-8 km thick.
Mostly basalt
Approx. 3.0 g/cc
Continental
Up to km thick.
Mostly granite
Approx. 2.7 g/cc

6. A. Crust Continent Ocean basalt granite 5 to 8 km thick 30 to 40
composed of
composed of
basalt
granite
that is
that is
5 to 8 km
thick
30 to 40
km thick

7. B. : Found below the crust. Has two parts:
: Upper, “plastic” mantle.
-partially melted material; 250 km; “weak sphere”
: Rest of mantle; actual temperature is below the melting point.
NOTE: The boundary between the crust and mantle is called the , or MOHO.
C : Only liquid layer of the earth; Composed mainly of iron.
2,200 km
D : Solid, innermost layer of Earth; Composed mainly of iron and nickel.
1,228 km
Mantle
Asthenosphere
Stiffer Mantle
Mohorovicic Discontinuity
Outer Core
Inner Core

8. Stiffer Mantle Asthenosphere is is Partially melted Not melted
B. Mantle
Stiffer
Mantle
Asthenosphere is is
Partially
melted
Not
melted

9. A. Inner Core A. Outer Core Only liquid layer Solid center of Earth
composed of
composed of
Iron and
Nickel
Iron

10. B. Crustal Movement I. Dynamic Crust
-The crust and outermost part of the Mantle is called the
: “rock sphere”; km thick, outermost
and rigid
A. The first theory of crustal movement was introduced in 1915 by Alfred Wegener, and was called
--Evidence for this theory include: 1.
2. Correlation of rock layers/fossils:
lithosphere
The Theory of Continental Drift
Edges of continents fit together like puzzle pieces
Rock layers and fossils
Found on opposite sides of ocean basins match up.

11. Puzzle Pieces that Fit

12. FOSSILS

13. 3. Mountain chains:
4. Climate evidence:
5. Crustal age:
Some mountain chains seem to be continuous from continent to continent.
Ancient climates were different from today. Ex: glacial deposits in tropical regions; coal deposits in Antarctica.
Rocks of the ocean basins are much younger than continental rocks.

14. Climate

15. Continental drift mountain chains climate evidence crustal age crustal
puzzle
fit of
continents
correlation
of rock
layers
mountain
chains
climate
evidence
crustal age
crustal
age

16. Sea-floor spreading
B. Sea Floor Spreading: Theory that states that ocean floors are forming and spreading out from the ridges.
1. Convection cell: Driving force for Spreading theory. Hot, molten material from the mantle pushes upward, cools and solidifies at the surface to form new ocean rock.

18. 1. Evidence
a. Igneous Ocean Rocks:
b. Magnetic Reversal:
Evidence shows that igneous rock formed at the ocean ridges is younger than rock found further from the ridges
As molten ocean rock cools, the magnetic minerals in the rock align themselves with the Earth’s magnetic field. If the magnetic field is opposite what it is today, the minerals will point to the south magnetic pole. The ocean rocks show that during past history, Earth’s magnetic field has reversed a number of times.

19. Sea Floor Spreading Igneous Ocean Convection rocks Cells Magnetic
evidence
driven by
Igneous
Ocean
rocks
Convection
Cells
Magnetic
Reversal

20. PLATES
C. Plate Tectonics: States that Earth’s lithosphere is made up of a number of solid pieces, or plates, that move in relation to each other.
Pacific Plate is the
largest plate
Text

21. I. Plate Boundaries
A. Convergent:
--3 Types:
: Two continental plates coming together.
Ex:
Two plates coming together.
Continental-Continental
India-Asia boundary (Himalayas)

22. Continental-Continental Convergence

23. I. Plate Boundaries
A. Convergent
: Oceanic and Continental plates coming together.
--Typically will form an along a
, where the ocean plate pushes under
the continental plate.
Ex:
Continental-Oceanic
ocean trench
subduction zone
West Coast of South America

24. Oceanic-continental convergence
South American Plate and Nazca Plate colliding

25. I. Plate Boundaries
A. Convergent
: Two ocean plates coming together.
--Typically will form an as one plate pushes under the other.
Ex:
B. Divergent:
-- Usually form: Ex :
Oceanic-Oceanic
island arc
Marianas Trench
Two plates moving opposite each other.
ocean ridges
mid-Atlantic Ridge

26. Oceanic-Oceanic Convergence

27. Continental- Continental Plate Boundaries Plate Tectonics Convergent
meet at
Convergent
moving
plates
come
together
Examples
Continental-
Oceanic
Oceanic-
Oceanic
Continental-
Continental
Continental-
Continental
Continental-
Continental

28. Plate
Boundaries
Divergent
Move
apart

29. Divergent Plates
Text

30. I. Plate Boundaries
C. Transform Fault:
-Forms where
Ex:
Two plates sliding horizontally past each other.
two plates move past each other without subduction occurring.
San Andreas Fault, California

31. Plate
Boundaries
Transform
Move
Horizontally
Past Each
Other

32. Transform Boundaries

33. C. Evidence of Crustal Activity
I. Crustal Activity
A. Deformed Rock Strata
--Originally, sedimentary rocks form
However, observations made of Earth’s surface indicate that
This includes:
1. Tilting:
flat, horizontal layers.
original rock formations have been changed
through past Earth movements.
Rock layers are found at an angle to their original formation.

34. 1. Folding:
2. Faulting:
Rock layers get warped, or bent as a result of compression.
Pressure on rock layers causes them to break. The boundary between the broken layers is called a fault.

35. 2. a. Types of faults
There are three types of forces that cause faulting

36. 1. Normal The force of tension causes normal faulting.
Normal faulting is when the hanging wall moves downward.
This type of faulting is common at divergent plate boundaries.
Examples of this type of faulting are the Sierra Nevada mountains and the eastern border of California.

37. 2. Reverse The force of compression causes reverse faulting.
Reverse faulting is when the hanging wall moves up.
This type of faulting is common at convergent plate boundaries.
An example of this faulting is the Rocky Mountains.

38. 3. Strike Slip The force of shearing causes strike-slip faulting.
Movement along this type of fault is not up and down, but sideways.
This type of faulting is common at transform plate boundaries.
Examples of this type of faulting is the San Andreas fault.

39. B. Displaced fossils:
Shallow water fossils have been found at high elevations, and deep water fossils have been found in shallow water areas. This means the crust has been moved.

40. crustal activity deformed rock displaced strata fossils tilting
shallow
fossils
at high
elevation
deep fossils
in shallow
water areas
tilting
folding
faulting
faulting

41. Results of Crustal Activity
I. Results of Crustal Activity
A. Earthquakes: Sudden movement of rocks along a fault which releases a large amount of energy. This energy is the earthquake.
--focus: The point in the earth where the earthquake occurs.
--epicenter: The point on the surface directly above the focus

42. --Types of earthquake waves:
: Also called compressional waves; the motion of the ground is parallel to the direction of wave motion. These waves can pass through
Primary (P) waves
solid or liquid material.

43. : Also called compressional waves; the motion of the ground is perpendicular to the direction of wave motion. These waves can pass through
Shear (S) waves
solid material only.
: Waves that ripple the surface of the Earth, causing most of the damage of an earthquake.
Long (L) waves

44. --When traveling through the same material,
travel faster than
-Since these waves travel at different speeds in different density materials, we can use earthquake waves to tell us about the interior of Earth. When an earthquake occurs, both P waves and S waves are released. In many places on Earth, both waves are received; however, in other places, only P waves are received. Since S waves cannot pass through a liquid, the conclusion is that
P waves
S waves.
some part of Earth’s interior is liquid.

45. results of
crustal
activity
Earthquakes
types
of waves
P waves
S waves
L waves

46. -If an earthquake occurs under the ocean, the energy is also released through the ocean water. When it reaches the coastline of a continent or island, it may form a large, fast moving wave called a
They may move at speeds of and may be !!!!
tsunami
200 mph
150 ft. high

47. A. Earthquake Strength
-The strength of an earthquake can be determined in one of two ways:
: Used to describe the amount of energy released by an earthquake. It ranges from to , and each increase on the scale indicates a release of times more energy!!!
--To record earthquake waves, seismologists use a
, which can be used to record the arrival time of the waves and the intensity of the waves.
Richter Scale 9 32
seismograph

48. 1. : Used to describe the earthquake in terms of the amount of damage done. It ranges from to .
--Why is the Richter scale better to compare earthquakes that occur in different places on Earth?
Modified Mercalli Scale I
XII
It compares the amount of energy released, which is constant for the same intensity earthquake.

49. Earthquakes
measured
using
Richter
Scale
Mercalli
Scale

50. A. Volcanoes:
--How do they form?
1. Molten rock from within the earth, called , along with gases, begins to rise up through cracks and weak spots in the crust.
2. When this molten material, along with gases from inside earth, break through the surface, it may flow out on the surface, and then it is called
--Where do they form? 1. 2.
: Weak points in the crust, located over unusually high heat flow in the mantle. Although the crust may move,
-Ex:
magma
lava
In mountain ranges formed along continental-oceanic boundaries.
Along ocean ridge systems
Hot spots
the hot spot remains in the same place in the mantle
Hawaiian Island chain

53. Volcanoes Shield lava lava and ash Composite ash and cinder Cinder
erupts
lava
lava and
ash
Composite
erupts
ash and
cinder
Cinder
erupts