1. Plate Tectonics 2015

2. The Earth is divided into 4 layers.

3. CRUST
MANTLE
INNER CORE
OUTER CORE

4. The Crust Layer of rock that forms Earths outer skin
Solid rock included both dry land and ocean floor (rocks, mountains, soils, water)
Thin layer (similar to paper thin layer of an onion)
Ranges from 5-40 km thick (70km underneath mountains)
Composition: oxygen, silicon, aluminum, calcium, iron, sodium, potassium, magnesium
Basalt = oceanic crust
Granite = continental crust
Temperature: whatever is on the surface

5. Crust
The plates move along smoothly but sometimes they get stuck and pressure builds up.

6. Mantle Rock that is very hot and bendable but solid at the same time.
Solid upper mantle and crust = lithosphere (100km thick)
Under lithosphere = asthenosphere
So hot that it behaves like a plastic material; it flows
2,900 km thick
Temperature 870°C
Composition: silicon, oxygen, iron, magnesium

7. Mantle
The movement of the mantle create the movement of the Earth’s plates.

8. Outer Core Inner Core Composition: iron and nickel Temperature: 2200°C
State of Matter: thick liquid (molten metal)
LOTS of pressure
2,250 km thick
Inner Core
Composition: iron and nickel
Temperature: 5000°C
State of Matter: Dense solid metal
Extreme pressure (squeezes that atoms of iron and nickel so much they can’t spread out and become liquid)
1,200 km thick

9. Earth’s Magnetic Field
Currents in the liquid outer core force the solid inner core to spin. The inner core spins at a slightly faster rate than the earth’s rotation. Because of this movement, it causes Earth to act like a giant bar magnetic. The magnetic field protects us from the sun’s damaging UV rays.

10. Earth’s Magnetic Field
Earth is a gigantic magnet surrounded by a magnetic field
Dipole (bar magnet)
Source is the liquid outer core
Molten iron in the liquid outer core flows around the solid inner core
Unlike bar magnet the Earth’s field changes over time

11. Convection Currents
As liquid heats up, it becomes less dense and rises. When it is away from the heat source, it cools down and becomes more dense and sinks. Heat from the lower mantle and the cores (inner and outer) cause convection currents in the asthenosphere.
Heat source
Moves up
Heats Up
Cools Down
Moves down

14. Plate tectonics
– theory that states that pieces of the lithosphere are in constant slow motion driven by convection currents in the mantle

15. Convergent Boundaries
Two plates collide
The denser plate sinks below the more buoyant plate in a process called subduction.
Examples
Ocean-Continent: Subduction and Volcanic arc
Cascade Mountains (Mt. St. Helens, Mt. Rainier), Andes Mountains
Continent-Continent: Mountains Form
Himalayan Mts.
Ocean-Ocean: Subduction and Volcanic Arc
Lesser Antilles

16. Divergent Boundaries Two plates separating Examples
Ocean-Ocean: Seafloor spreading
Mid-Atlantic Ridge
Continent-Continent: Widening and separating of land
Eurasian Plate, African Rift Valley

17. Transform Boundaries Two plates slide horizontally past one another
Examples
Continent-Continent: Earthquakes
San Andres Fault
Ocean-Ocean: Earthquakes
East Pacific Rise

18. Plate Boundaries Foldable

19. Plate Motion Data Table
Page 35 1 2 3 4 5 6 7
Plate Name
Latitude
within Plate
Longitude
Revised Latitude
(degrees N (+), S (-))
Revised Longitude
(degrees E(+), W(-))
Direction
(clockwise from N)
Speed
(mm/yr)
Example
20°S
120°E
-20
+120
 Pacific
20 N
160 W
 North American 
60 N
60 W
 Caribbean
 15 N
80 W 
 Eurasian
40 N
Nubia/African
Cocos
10 N
110 W
South American

20. Plate Motion Data Table
Page 35 1 2 3 4 5 6 7
Plate Name
Latitude
within Plate
Longitude
Revised Latitude
(degrees N (+), S (-))
Revised Longitude
(degrees E(+), W(-))
Direction
(clockwise from N)
Speed
(mm/yr)
Example
20°S
120°E
-20
+120
 Pacific
20 N
160 W
+20 
 -160
 North American 
60 N
60 W
 +60
 -60
 Caribbean
 15 N
80 W 
 +15
 -80
 Eurasian
40 N
+40
Nubia/African
Cocos
10 N
110 W
+10
-110
South American
-60

21. Plate Motion Data Table
Page 35 1 2 3 4 5 6 7
Plate Name
Latitude
within Plate
Longitude
Revised Latitude
(degrees N (+), S (-))
Revised Longitude
(degrees E(+), W(-))
Direction
(clockwise from N)
Speed
(mm/yr)
Example
20°S
120°E
-20
+120
 Pacific
20 N
160 W
+20 
 -160
-59.73 
105.11
 North American 
60 N
60 W
 +60
 -60
 245.22
 25.67
 Caribbean
 15 N
80 W 
 +15
 -80
 252.93
 29.68
 Eurasian
40 N
+40
239.35
20.12
Nubia/African
249.12 16
Cocos
10 N
110 W
+10
-110
25.5
16.95
South American
-60
257.34
46.76

22. Which plates do you think will impact North America
Which plates do you think will impact North America? Shade it in with your pencil
Add the names of those plates to column 1
Choose a location with in each plate where it is easy to read the latitude and longitude.
Put a dot on the location
Add the latitude and longitude of each location within the plate to the columns 2 and 3
Convert the latitude and longitude of the locations and enter them into columns 4 and 5
Revised Latitude:       If location is °N the number is positive. (20°N = +20) If location is °S the number is negative. (20°S = -20)
Revised Longitude:     If location is °E the number is positive. (20°E = +20) If location is °W the number is negative. (20°W = -20)
Then go to the plate motion calculator site (
Enter the name of the plate and your revised latitude and revised longitude (column 4,5) for the location within that plate. Click on Execute calculation.
Enter Speed (Rate) and Direction (Azimuth) into the table. Note: “cw” stands for clockwise.

23. Seafloor Spreading Notes Read pages 194-200 in the textbook
Seafloor Spreading Notes Read pages in the textbook. Then answer the following questions and define the words below
Page 36
What is seafloor spreading?
What evidence is used to support seafloor spreading?
mid-ocean ridge
seafloor spreading
magnetic reversal
normal polarity
reversed polarity

24. Seafloor Spreading Notes
Read pages in the textbook. Then answer the following questions
What is seafloor spreading?
What evidence is used to support seafloor spreading?
mid-ocean ridge - mountain range located on the seafloor in the middle of the ocean
seafloor spreading - new oceanic crust forms at a mid-ocean ridge as - old oceanic crust moves away from the ridge
magnetic reversal - event in which the magnetic field reverses direction
normal polarity - today’s magnetic field; magnets orient themselves to point north
reversed polarity - magnetic field in - which magnets orient themselves to point south

25. Process of Seafloor Spreading
At the mid ocean ridge molten material comes up from the mantle, cools, hardens and becomes new crust
The new crust spreads out and pushes the old rock to the sides in a continuous process
When older oceanic crust reaches a continental crust the more dense oceanic plate is subducted down and forms a trench on the surface.
The older crust melts back into the mantle and is recycled by convection currents

26. Draw and label the diagram representing seafloor spreading and subduction zones
Volcanic arc
Oldest rock
Newest rock
Seafloor spreading
Basalt
Subduction zone
Granite
Convection currents
Oceanic crust
Mantle
Continental crust
Magma
Divergent boundary
Convergent boundary
Mid-ocean ridge
Trench

27. Draw and label the diagram representing seafloor spreading and subduction zones
Divergent boundary
Seafloor spreading
Convergent boundary
Subduction zone
Mid-ocean ridge
Convection currents
Basalt
Trench
Mantle
Granite
Volcanic arc
Oceanic crust
Oldest rock
Continental crust
Newest rock

28. Draw and label the diagram representing seafloor spreading and subduction zones
Divergent boundary
Seafloor spreading
Convergent boundary
Subduction zone
Mid-ocean ridge
Convection currents
Basalt
Trench
Mantle
Granite
Volcanic arc
Magma
Oceanic crust
Oldest rock
Continental crust
Newest rock

29. Draw and label the diagram representing seafloor spreading and subduction zones
Divergent boundary
Seafloor spreading
Convergent boundary
Subduction zone
Mid-ocean ridge
Convection currents
Basalt
Trench
Mantle
Granite
Volcanic arc
Magma
Oceanic crust
Oldest rock
Continental crust
Newest rock

31. On your own piece of paper Boundaries Tour
Type of Boundary
Location
Crust Type
Subduction? Volcano? Earthquake?
Mountain?

32. Fault Notes Use the Orange Textbook pages 54-57 page 38-39 Word
Definition
stress
deformation
Fault
Hanging wall
Footwall
Word
Definition
Diagram
tension
compression
shearing
Strike-Slip Fault
Normal Fault
Reverse Fault

33. Faults
Stress – a force that acts on rock to change its shape or volume
Strain - a change in the shape of rock caused by stress
Compression – squeezing stress
Tension – stress that pulls something apart
Shear – parallel forces acting in opposite direction
Fault - A break in the Earth’s crust where slabs of rock slip past each other

34. Shearing, tension and compression work over millions of years to change the shape and volume of rock
Any change in the volume of Earth’s crust is called deformation. It causes the crust to bend, stretch, break, tilt, fold and slide.

35. Three Types of Faults Strike-Slip Thrust (Reverse) Normal
Form depending on type of plate motion and complex reaction of earth’s lithospheric blocks
Strike-slip
Normal
Thrust
Strike-Slip
Thrust (Reverse)
Normal

36. Forms the upper half of the fault
Block of rock that forms the lower half of a fault
Hanging Wall Footwall

37. Strike-Slip Fault
Shearing creates strike slip faults. Rocks on either side of the fault slip past each other sideways with little up or down motion
Before earthquake manure pile was under window where farmer shoveled it out from inside
Fault runs right under corner of barn
After earthquake manure pile moved over about 10 feet

38. Normal Faults
Tension forces cause these faults. The fault is at an angle so that one block lies above the fault while the other lies below the fault.

39. Reverse (Thrust) Faults
Compression forces. Has the same structure as a normal fault, but the blocks move in the opposite direction.

40. Mountain Building
Over millions of years, fault movement can change a flat plain into a towering mountain range
Form by Faulting
Folding
Anticlines and Synclines
Plateaus

41. Fault-Block Mountains
A Mountain that forms where a normal fault up lifts a block of rock.
Fault block mountains are distinguished by great sheer rock faces. These form when enormous underground pressure forces a whole rock mass to break away from another. The line at which this break takes place is called a fault.

42. Folding Mountains
Pushing together of part of the earth's crust from the ends, causing it to fold and ripple in the middle.
Some great examples of this mountain type are the Appalachians of North America, the Swiss Alps, the Atlas Mountains of Northern Africa, and the Zagros mountains of Iran

43. Anticline and Syncline
Anticline – a fold in rock that bends upward
Syncline – a fold in rock that bends downward in the middle to form a bow;

44. Plateaus
Large area of flat land elevated high above sea level. Some form when vertical faults push up a large flat block of rock

47. Discuss with your partner/neighbor
What are the 3 main types of stress in rock?
Describe the movements that occur along each of the three types of faults.
How does Earth’s surface change as a result of movement along faults?
If plate motion compresses part of the crust, what landforms will form there in millions of years?

48. Earthquakes
Earthquake – the shaking and trembling that results from the movement of rock beneath Earth’s surface
Focus – point beneath Earth’s surface where the rock is under stress breaks, triggering an earthquake
Epicenter – the point on the surface directly above the focus
Seismic waves – vibrations that travel through Earth carrying the energy released during the earthquake

49. Seismic Waves

50. Seismic waves carry the energy of an earthquake away from the focus, through Earth’s Interior and across the surface.
Energy is greatest at the epicenter
But the most violent shaking can occur km away from the epicenter

51. Primary waves. - (P waves) arrive first;. earthquake waves that
Primary waves - (P waves) arrive first; earthquake waves that compress and expand the ground like an accordion.
Secondary waves - (S waves) come after the p waves; earthquake waves that vibrate from side to side and up and down. S waves cannot move through liquids.
Surface waves – when P and S waves reach the surface; they move more slowly but produce the most severe ground movements

52. Seismic Waves
Through the Earth

53. Seismograph. – records the ground. movements caused by
Seismograph – records the ground movements caused by seismic waves as they move through the Earth

54. Measuring Earthquakes
Magnitude – measurement of earthquake strength based on seismic waves and movements along the faults
Mercalli Scale – rates earthquakes to their intensity and how it affects people, buildings and land surface
Richter Scale - rating the size of seismic waves as measured by a seismograph. Accurate measurement for small nearby earthquakes

56. Moment Magnitude Scale
Moment magnitude scale can be used to rate earthquakes of all sizes near or far. Estimate the total energy released by earthquakes
Colorado
Earthquake tracking

57. Locating an epicenter

59. Ring of Fire
Area of earthquake and volcanic activity surrounding the Pacific Ocean

60. Volcanoes
Weak spot in the crust where molten material called magma rises to the surface where it is renamed lava.
The amount of silica in magma determines how easy the magma flows and if eruptions are quiet or violent

61. Types of Eruptions
Quiet Eruptions - Magma with low amounts of silica and low viscosity erupts to form shield volcanoes.
Violent Eruptions - Magma with high amounts of silica and high viscosity erupts explosively to form composite cones.

62. Types of Rocks Obsidian
Forms when lava cools very quickly, giving it a smooth glassy surface
Pumice
Forms when gas bubbles are trapped in cooling lava, leaving spaces in the rock

63. States of Volcanoes
Active – currently erupting or showing signs of unrest (ex: earthquake activity or gas emission)
Dormant – not currently active, but could become restless or erupt
Extinct – unlikely to erupt again

64. Shield Volcano
Repeated lava flows during quiet eruptions build up a broad gently sloping volcanic mountain. Ex: Mauna Loa, Hawaii

65. Cinder cones
When cinders erupt explosively from volcanic vents, they pile up around the vent forming a cone shaped hill. Ex: Sunset Crater, Arizona

66. Cinder cone volcano in the Mojave National Preserve, California

67. Composite
Layers of lava alternate with layers of ash, cinders and bombs in a composite; both quiet and explosive eruptions. Ex: Mt. Hood, Oregon

68. Composite volcanoes
Examples of composite volcanoes include Italy's Vesuvius, Japan's Mount Fuji, and Washington State's Mount Rainier and Mount St. Helens
Mt. Rainier, Washington state
Mt. Fuji, Japan
Mt. Vesuvious 1943, infrared photo at night
Mt. St Helens, Washington state

69. Hawiian islands are formed this way
Slow quiet lava flows build up the land (constructive) until the land is thicker than the water and forms an island

70. Hot Spots
An area where magma melts through the crust like a blow torch; they lie in the middle of plate. Ex: Hawaiian Islands