1. Planet Earth Preview Understanding Concepts Reading Skills
Interpreting Graphics

2. Understanding Concepts
1. If a geologist dug a shaft down to the bottom of
the lithosphere, how deep into Earth would the
shaft go?
A. to the bottom of the crust
B. through the crust and partway into the mantle
C. to the bottom of the mantle
D. through the mantle and into Earth’s core

3. Understanding Concepts
1. If a geologist dug a shaft down to the bottom of
the lithosphere, how deep into Earth would the
shaft go?
A. to the bottom of the crust
B. through the crust and partway into the mantle
C. to the bottom of the mantle
D. through the mantle and into Earth’s core

4. Understanding Concepts, continued
2. Which type of wave coming from an
earthquake’s epicenter travels the fastest and
reaches detection stations first?
F. longitudinal wave
G. transverse wave
H. standing wave
I. surface wave

5. Understanding Concepts, continued
2. Which type of wave coming from an
earthquake’s epicenter travels the fastest and
reaches detection stations first?
F. longitudinal wave
G. transverse wave
H. standing wave
I. surface wave

6. Understanding Concepts, continued
3. In the Mississippi Delta, minerals eroded from
riverbanks upstream are deposited in the soil
of a wide floodplain. What type of rock does
this process create?
A. sedimentary rock
B. igneous rock
C. metamorphic rock
D. progressive rock

7. Understanding Concepts, continued
3. In the Mississippi Delta, minerals eroded from
riverbanks upstream are deposited in the soil
of a wide floodplain. What type of rock does
this process create?
A. sedimentary rock
B. igneous rock
C. metamorphic rock
D. progressive rock

8. Understanding Concepts, continued
4. An earthquake that measures 6 on the Richter
scale is how many times as powerful as one
that measures 3?
F. 3
G. 30
H. 900
I. 27,000

9. Understanding Concepts, continued
4. An earthquake that measures 6 on the Richter
scale is how many times as powerful as one
that measures 3?
F. 3
G. 30
H. 900
I. 27,000

10. Understanding Concepts, continued
5. What is the difference between lava and
magma?

11. Understanding Concepts, continued
5. What is the difference between lava and
magma?
Answer: Magma is under the surface of Earth, lava is above the surface of Earth.

12. Understanding Concepts, continued
6. What do mid-oceanic ridges, rift valleys,
volcanoes, and mountain ranges have in
common?

13. Understanding Concepts, continued
6. What do mid-oceanic ridges, rift valleys,
volcanoes, and mountain ranges have in
common?
Answer: They all may form at the boundaries of tectonic plates.

14. Reading Skills GAZING INTO THE DEEP
The deepest valley ever discovered is an undersea trench called the Mariana Trench. It is located in the Pacific Ocean, north of Indonesia and south of Japan. The Mariana Trench is located at the boundary of two tectonic plates. As the tectonic plates slowly grind into each other, the Pacific plate flexes and slips underneath the Philippine plate. This movement creates a deep valley at the plate boundary. Nearby the Mariana Trench are the Mariana Islands, a ridge of volcanic islands created by the same subduction forces. As the Philippine plate is thrust upward, its crust buckles and magma comes up through the cracks. This process creates the volcanic islands. Although there are only 15 volcanic summits above sea level in the Mariana Islands, they are just the southernmost tip of a submerged mountain range. The range extends more than 2,500 km from Guam to near Japan and parallels the border between the tectonic plates.

15. Reading Skills, continued
7. What can you tell about the lithosphere
containing the Pacific plate from the information in the passage?
A. The Pacific plate is larger than the Philippine plate.
B. The lithosphere of the Pacific plate is denser than the lithosphere of the Philippine plate.
C. The lithosphere of the Pacific plate is moving away from the lithosphere of the Philippine plate.
D. The boundary between the Pacific plate and the Philippine plate is a transform fault boundary.

16. Reading Skills, continued
7. What can you tell about the lithosphere
containing the Pacific plate from the information in the passage?
A. The Pacific plate is larger than the Philippine plate.
B. The lithosphere of the Pacific plate is denser than the lithosphere of the Philippine plate.
C. The lithosphere of the Pacific plate is moving away from the lithosphere of the Philippine plate.
D. The boundary between the Pacific plate and the Philippine plate is a transform fault boundary.

17. Interpreting Graphics
The graphic below shows the steps of the rock cycle. Use this graphic
to answer questions 8–9.

18. Interpreting Graphics, continued
8. Which of the processes on the flow chart takes
place only under conditions of great heat and
pressure?
F. metamorphism
G. lithification
H. weathering
I. melting

19. Interpreting Graphics, continued
8. Which of the processes on the flow chart takes
place only under conditions of great heat and
pressure?
F. metamorphism
G. lithification
H. weathering
I. melting

20. Interpreting Graphics, continued
9. Which of the processes named in the flow chart
can take place above the surface of Earth?

21. Interpreting Graphics, continued
9. Which of the processes named in the flow chart
can take place above the surface of Earth?
Answer: cooling and weathering

22. Interpreting Graphics
The graphic below displays the paths taken by primary (P) waves and
secondary (S) waves. Use this graphic to answer questions 10–11.

23. Interpreting Graphics, continued
10. Through which layer of Earth can both P waves and S waves travel?
A. the shadow zone
B. the mantle
C. the outer core
D. the inner core

24. Interpreting Graphics, continued
10. Through which layer of Earth can both P waves and S waves travel?
A. the shadow zone
B. the mantle
C. the outer core
D. the inner core

25. Interpreting Graphics, continued
11. How would knowing the wave patterns shown in the graphic help locate the epicenter of an earthquake?

26. Interpreting Graphics, continued
11. How would knowing the wave patterns shown in the graphic help locate the epicenter of an earthquake?
Answer: Seeing where the P and S waves stop on the other side of the planet should indicate the location of the epicenter.