Name: ____________________________________________ Date: ___________ Block: _______ P#: ______
Unit STUDY GUIDE--“Earth’s Layers & Plate Tectonics”
Section 1: Earth’s Layers
Directions: Label the diagram with the terms provided.
Asthenosphere
Crust
Inner Core
Lithosphere
Lower Mantle
Outer Core
Upper Mantle
Asthenosphere
1
2 Upper Mantle
plastic layer
3 Lithosphere
4 Crust
5 Lower Mantle
6 Outer Core
7
Inner Core
Directions: Answer the following questions in the spaces provided.
8. What part of the Earth varies in thickness? Crust
9. What is the part of the Earth that the lithospsheric plates float on? Asthenosphere
10. What is the part of the Earth that includes the crust and the upper mantle and is split into plates?
lithosphere
11. Write the layers of the earth in order based on the following characteristics:
a. surface to center- crust, mantle, outer core, inner core
b. coolest to hottest- crust, mantle, outer core, inner core
c. thinnest to thickest- crust, inner core, outer core, mantle
d. least dense to most dense- crust, mantle, outer core, inner core
12. For each layer, write the state of matter (solid, liquid, or solid and liquid).
a. crust- solid
c. outer core- liquid
b. mantle-liquid & solid
d. inner core- solid
13. List to two types of crust. Oceanic and continental
Section 2: Plate Tectonics
Directions: Answer the following questions in the spaces provided.
14. What are the large pieces of the lithosphere that move around on the Earth’s surface called?
Tectonic plates (also known as lithospheric plates).
15. What is the hypothesis that states that the continents were once a large mass that broke apart?
Continental drift
16. What did Alfred Wegener call the “supercontinent”? Pangaea
17. What is Seafloor Spreading? the process by which new oceanic lithosphere forms at mid-ocean
ridges
18. What is some evidence to support Seafloor Spreading? Crust is older farther out from MAR – core
samples
19. What is the theory that the Earth is divided into plates that move around? Plate Tectonics
20. What is some evidence to support this theory? Continental Drift, Convection Currents, Fossils,
Seafloor Spreading, MAR
21. What new material is formed in the ocean when sea-floor spreading occurs? Oceanic lithosphere
22. What can tectonic plates form when they converge? Mountains, subduction zones,
23. Draw a convergent boundary. 24. Draw a divergent boundary. 25. Draw a transform boundary.
The 2 lithospheric plates
Collide with each other.
26. Draw a Normal Fault.
How does the hanging wall
move relative to the
footwall? down
The 2 lithospheric plates
Move away from each
other.
27. Draw a Reverse Fault.
How does the hanging wall
move relative to the foot
wall? up
The 2 lithospheric plates
Slide past each other.
28. Draw a strike-slip fault.
How does the hanging wall
move relative to the foot
wall? horizontal
29. What is compression? The stress that occurs when forces act to squeeze an object
30. What type of fault usually occurs because of compression? reverse
31 What is tension? Stress that occurs when forces act to stretch an object
32. What type of fault usually occurs because of tension? Normal
33. What is a convection current (include what it does)? The circulation of hot and cool magma, where the
hot magma rises and the cool magma sinks, causing the tectonic plates to move
34. What are the 3 types of convergent boundaries?
35. What ype of boundary is the mid-atlantic ridge? Divergent
36.
37.
38.
39.
What is happening at the Mid-Atlantic Ridge? Divergent Boundary; new crust forming
What is subduction? When one plate gets pushed under another (sub = under)
What happens at subduction zones? Plate recycled back into the mantle
At a subduction zone, oceanic crust goes under continental crust. Why does this happen? Oceanic Crust
is thinner and more dense
Section 3: Earthquakes and Volcanoes
Directions: Answer the following questions in the spaces provided
40. Most earthquakes happen at the edges of tectonic plates
41. Earthquakes most commonly occur along which type of fault? Strike slip
42. What is an earthquake’s focus? The point along a fault at which the first motion of an
earthquake occurs (below the epicenter)
43. What is an earthquake’s epicenter? Point on Earth’s surface directly above the earthquake’s
starting point, or focus
44. What are seismic waves? The waves of energy from earthquakes that travel through Earth
(surface waves are the waves that will do the MOST damage  )
45. Describe the three types of seismic waves
P Waves = Primary waves: fastest, travel through all material, come first
S Waves = Secondary; only travel through solid, back and forth motion
Surface waves= up and down motion, do the most damage, last wave
46. What seismic waves do the greatest damage? Surface waves
47. What scale is used to measure an earthquake’s intensity? Richter
48. Draw a shield volcano
49. Draw a cinder cone volcano
50. Draw a composite volcano
51. Describe how each type of volcano forms:
Shield = lava quietly flows from vent
Cinder cone = small mt, cinders and rock particles blown into air
Composite = violent eruption, large mt, steep sides
52. How are volcanoes created? Magma is pushed up to the surface of the Earth
53. How is an explosive eruption different than a non Explosive eruption? explosive = rarer, destructive,
pyroclastic material; non explosive = more common, on land and ocean, calm flows of lava
54. What is pyroclastic flow? Why are they dangerous? Magma explodes and solidified in the air;
temps can exceed 700 Celsius; can be faster than 200 km/h
55. Where do volcanoes typically occur? –they are most likely to form along plate boundaries