1 of 118

Unit 5: Plate Tectonics

2 of 118

Tuesday 3/26��BW: Where does Earth get its energy from? Give an example of how it gets energy from this source.

2

3 of 118

Energy in Earth’s Four Spheres

  1. Geosphere
  2. Hydrosphere
  3. Atmosphere
  4. Biosphere

3

4 of 118

Where does the energy in all four spheres come from?

4

5 of 118

Key Idea: The vast majority of ALL energy in the four spheres comes from the SUN

5

6 of 118

Hydrosphere: All the water on Earth (oceans, lakes, ponds, water in soil, etc.)

6

7 of 118

Energy in the Hydrosphere

7

8 of 118

Energy in the Hydrosphere

  • The properties and motion of the hydrosphere are important in MAINTAINING DIVERSE CLIMATES that exist worldwide
  • The Ocean (97% of water on Earth) serves as a reservoir which contributes to how much SOLAR RADIATION (ENERGY) is absorbed.
  • The ocean serves to REDISTRIBUTE ENERGY AND HEAT around the globe, contributing to the different average temperatures that exist over the globe

8

9 of 118

Atmosphere: All the gases surrounding Earth (oxygen, nitrogen, methane, etc.)

9

10 of 118

Energy in the Atmosphere

10

11 of 118

Wednesday 4/3

​

BW: What are the four spheres of earth? Describe the transport of energy within the sphere that accounts for all of earth’s water.

11

12 of 118

Energy in the Atmosphere

  • The atmosphere ABSORBS ENERGY FROM THE SUN in different ways to support life on Earth:
    • Protects life on Earth by SHIELDING IT FROM INCOMING ULTRAVIOLET RADIATION
    • Keeps planet warm THROUGH INSULATION
    • Preventing extremes between day and night temperatures
  • The sun heats layers of the atmosphere causing it to convect DRIVING AIR MOVEMENT and WEATHER PATTERNS around the world.

12

13 of 118

Biosphere: All the living things surrounding Earth (plants, animals, and humans)

13

14 of 118

Energy in the Biosphere

14

15 of 118

Energy in the Biosphere

  • Energy flows from the sun to PRODUCERS (ex: plants) which are the source of all energy in an ecosystem
  • DECOMPOSERS return the energy from dead animals to the soil for producers to use

15

16 of 118

Geosphere: All the rock on Earth (all the way down to the core)

16

17 of 118

The Layers of the Geosphere

  • The CRUST is Earth’s thin, cool, and rigid outermost rock layer
  • The MANTLE is Earth’s hot, middle rock layer, located between the crust and core
  • The CORE is Earth’s hot, dense, innermost rock layer, located below the mantle

17

18 of 118

Energy Transfers Through Convection

  • CONVECTION causes the heated, less dense rock in the mantle near the core to RISE UPWARD, toward the crust
  • As it cools, the colder denser rock SINKS DEEPER into the mantle toward the core due to gravity

18

19 of 118

Brainstorm some changes that have happened to the Earth since the beginning of time

19

20 of 118

https://www.youtube.com/watch?v=U3EZlz8f7_c

20

21 of 118

Small Scale Changes

  • Weathering is the breakdown of rock on Earth’s surface
  • Erosion is the removal of rock material by wind, water, ice, or gravity.
  • Deposition is the accumulation of eroded rock material that has been transported from another location

21

22 of 118

Many Small Changes Lead to Big Changes

22

23 of 118

23

24 of 118

Key Idea: Many SMALL changes add up to a LARGE change over time

24

25 of 118

Slow Changes and Fast Changes

25

26 of 118

Do you think these changes we talk about occur similarly to how they did in the distant past? Why or why not?

26

27 of 118

27

28 of 118

28

29 of 118

Key Concept: Uniformitarianism

Uniformitarianism: the idea that any natural processes we can observe today happened in the same way in the past and will also happen in the same way in the future

29

30 of 118

Key Idea: Earth is a DYNAMIC planet, always changing in BIG, SMALL, QUICK, and SLOW ways!

30

31 of 118

Tuesday 4/9

​

BW: How does energy pass through the biosphere?

31

32 of 118

Wednesday 4/10

​

BW: Name an example of a quick change that has happened to earth’s geology. Name an example of a slow change.

32

33 of 118

Monday 4/22

​

BW: What are the three pieces of evidence for Continental Drift Theory? Give an example within each.

33

34 of 118

Continental Drift Theory Skit

34

35 of 118

Tuesday 4/23

​

BW: Why did people dismiss Wegener’s theory of Continental Drift?

35

36 of 118

Tuesday 4/30

​

BW: How do you think the continents split apart? Don’t just say plate tectonics; be specific.

36

37 of 118

Seafloor Spreading

38 of 118

38

39 of 118

Seafloor Spreading: Process by which rocks on either side of the mid-ocean ridge slowly pull away from each other, allowing molten rock to rise and solidify, forming new seafloor

39

40 of 118

What evidence would be useful in proving seafloor spreading? (Hint: Think back to rock strata)

40

41 of 118

41

42 of 118

If seafloor spreading were occurring, then the seafloor closest to the mid-ocean ridge would be the youngest, and the seafloor farthest away from the mid-ocean ridge would be the oldest.

42

43 of 118

43

44 of 118

What is causing the seafloor to rise/spread?

44

45 of 118

Earth as a terrestrial planet has three distinct layers. What are the names of these three layers?

45

46 of 118

46

47 of 118

  • Convection causes the HEATED, LESS DENSE rock in the mantle to RISE UPWARD, toward the crust
  • Gravity causes the COOLER, MORE DENSE rock to SINK DEEPER into the mantle
  • This circular pattern of movement within the mantle of the Earth based on density is called a CONVECTION CYCLE

47

48 of 118

Friday 5/3

​

BW: What causes seafloor spreading?

48

49 of 118

If seafloor spreading is happening, what might you expect to be happening to the size of Earth?

49

50 of 118

In other parts of the seafloor, scientists discovered deep valleys called TRENCHES

50

51 of 118

51

52 of 118

What happens when two things collide and neither stops moving?

52

53 of 118

53

54 of 118

Subduction

  • Old seafloor moves back down under the trench through a process called SUBDUCTION
  • Subduction occurs when the collision between two tectonic plates forces the MORE DENSE plate under the LESS DENSE plate

​

What happens to the old sea floor during subduction?

54

55 of 118

55

56 of 118

https://www.youtube.com/watch?v=ZzvDlP6xd9o&

56

57 of 118

  • Scientists often refer to the crust/upper mantle layer as the lithosphere
  • This is made up of separate slabs called tectonic plates
  • These plates are 100 to 120 km thick and include the crust and a small part of the upper mantle

57

58 of 118

Monday 5/6

​

BW: What is the process of subduction and what causes it? (include words plates and dense)

58

59 of 118

Seafloor Spreading Model

  • You will create your own diagram of seafloor spreading. Be sure to show the following in your model and include captions that describe what is happening
    • Convection, subduction, mid-ocean ridge, trench, old rock, new rock
    • Also include the DIRECTION that the new rock and old rock follow using arrows

59

60 of 118

Tuesday 5/7

​

BW: What makes up a plate? If the continents drifted apart from one another, what must that mean about how the earth is structured?

60

61 of 118

Plate Tectonic Theory

62 of 118

  • Scientists often refer to the crust/upper mantle layer as the lithosphere
  • This is made up of separate slabs called tectonic plates
  • These plates are 100 to 120 km thick and include the crust and a small part of the upper mantle

62

63 of 118

If parts of the Earth’s lithosphere are moving in different directions, what must that mean about how it is structured?

63

64 of 118

64

65 of 118

Plate Tectonic Theory

  • PLATE TECTONICS: the theory that the lithosphere is made up of rigid pieces, called tectonic plates, that move across Earth’s surface
  • Tectonic plates carry the land or water on top of them and fit together like the PIECES OF A PUZZLE
  • There are 15 MAJOR PLATES and several smaller ones not shown

65

66 of 118

If plate tectonics is what has caused continental drift, how fast do you think the plates move?

66

67 of 118

What causes the plates to move?

67

68 of 118

68

69 of 118

  1. Mantle Convection: Convection in the mantle pushes new rock upward at the ridge
  2. Seafloor Spreading: this new rock solidifies and pushes old rock further and further away
  3. Subduction: the denser plate sinks into and becomes part of the mantle and the rock is recycled

69

70 of 118

Three Types of Boundaries

Tectonic Plates interact in THREE ways and form:

  • Convergent Boundaries
  • Divergent Boundaries
  • Transform Boundaries

70

71 of 118

Convergent Boundaries

71

72 of 118

Convergent Boundaries

  • A convergent boundary occurs where two plates move TOWARD EACH OTHER
  • When this happens, the MORE DENSE plate is subducted under the LESS DENSE plate
  • Subduction causes a TRENCH to form on the seafloor
  • The other plate rises toward the surface and results in VOLCANOES or MOUNTAINS

72

73 of 118

Divergent Boundaries

73

74 of 118

Divergent Boundaries

  • A divergent boundary occurs where two plates MOVE AWAY FROM each other
  • This process causes seafloor spreading, which causes OCEANS AND SEAS TO BECOME WIDER

74

75 of 118

Transform Boundaries

75

76 of 118

Transform Boundaries

  • A transform boundary occurs where two plates SLIDE HORIZONTALLY PAST EACH OTHER
  • The tectonic forces push on the plates in OPPOSITE DIRECTIONS, stress builds up along the transform boundary

76

77 of 118

Add the three types of boundaries to your guided notes

77

78 of 118

Wednesday 5/8

​

BW: What are the three types of boundaries? Choose one to describe in detail

78

79 of 118

What do you think happens when the tension of a transform boundary gets too great?

79

80 of 118

https://www.youtube.com/watch?v=VSgB1IWr6O4&

80

81 of 118

81

82 of 118

So where do volcanoes form and earthquakes happen?

82

83 of 118

83

84 of 118

Volcano Exploration:

https://www.nationalgeographic.org/forces-nature/volcanoes.html

84

85 of 118

In Summary:

https://www.youtube.com/watch?v=kwfNGatxUJI

85

86 of 118

Thursday 5/9

​

BW: Why are there so many volcanoes and hurricanes in the ring of fire?

86

87 of 118

Rock Cycle

88 of 118

88

89 of 118

What is a rock?

89

90 of 118

Not this rock…

90

91 of 118

What makes up a rock?

  • Rocks are composed of MINERALS

​

  • Minerals are composed of CRYSTALS

91

92 of 118

How do scientists classify different rocks?

92

93 of 118

How do you differentiate between rocks?

  1. Composition: What they are made of

​

  • Texture: Way it looks and feels

93

94 of 118

Three Types of Rocks

  • Igneous
  • Metamorphic
  • Sedimentary

94

95 of 118

Igneous Processes

  • Igneous rock forms when magma COOLS AND HARDENS
  • The TEXTURE of the rock is determined by how QUICKLY the magma cools
  • When magma starts to cool, its minerals begin to CRYSTALLIZE
  • The SLOWER the cooling, the LARGER the crystals will become

95

96 of 118

Intrusive Rock (Igneous)

INTRUSIVE ROCK is igneous rock that forms when magma slowly hardens BELOW Earth’s surface

​

Examples: Granite / Gabbro

96

97 of 118

Extrusive Rock (Igneous)

EXTRUSIVE ROCK is igneous rock that forms when magma cools quickly ON EARTH’S SURFACE (usually from volcanic eruption)

​

Examples: Pumice / Basalt

97

98 of 118

98

99 of 118

99

100 of 118

Friday 5/10

​

BW: What are the two types of igneous rocks? Describe both.

100

101 of 118

Metamorphic Processes

  • Metamorphic rock forms from when existing rocks are transformed by HEAT OR PRESSURE
  • They can be grouped into TWO categories based on how they FORM
    • Deformation
    • Recrystallization

101

102 of 118

102

103 of 118

103

104 of 118

104

105 of 118

Recrystallization - Changes the actual chemical makeup of the rock just like a cookie baking.

105

106 of 118

Brainstorm some ideas about how rocks might break down

106

107 of 118

Sedimentary Processes

  • Sedimentary rocks form from the COLLECTION AND CEMENTATION of dissolved minerals, rock fragments, or the remains of organisms
  • Preexisting rocks are broken down through a process called WEATHERING

107

108 of 118

https://vimeo.com/94208870

108

109 of 118

109

110 of 118

Two Types of Weathering

Physical Weathering

  • The breakdown of rock by physical processes (rain, water, wind, etc.) is called PHYSICAL WEATHERING
  • Only changes the SIZE OR SHAPE of the rock!

Chemical Weathering

  • Rock can react chemically when exposed to air, water, soil, and organisms through CHEMICAL WEATHERING
  • Changes the COMPOSITION of the rock!

110

111 of 118

Key Idea: All weathering eventually leads to sediment (small pieces of broken-down rock) which then form sedimentary rocks

111

112 of 118

Forming of Sedimentary Rock: Erosion vs. Deposition

EROSION is the action of surface processes that REMOVES weathered soil, rock, or dissolved material from one location and then TRANSPORTS IT TO ANOTHER LOCATION

​

This is a DESTRUCTIVE process

DEPOSITION is when sediments, soil, or rocks are ADDED to the land. Eventually, these rocks form layers through a process called CEMENTATION

​

This is a CONSTRUCTIVE process

112

113 of 118

113

114 of 118

Key Idea: The Rock Cycle is a continuous set of processes by which any type of rock can CHANGE into any other type.

114

115 of 118

115

116 of 118

116

117 of 118

What Drives the Rock Cycle?

  • SOLAR ENERGY from the SUN which causes weathering and erosion by wind and water
  • INTERNAL ENERGY from the Earth’s CORE which causes magma

117

118 of 118

In Summary: https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:the-geosphere/x87d03b443efbea0a:the-rock-cycle/v/the-rock-cycle

118