Module 6

Question 1

1a. define: earth’s crust

Answer 1

earth’s outermost layer of rock

Question 2

1b. define: sediment

Answer 2

Small, solid fragments of rock and other materials that are carried and deposited by wind, water, or ice. Examples would be sand, mud, or gravel.

Question 3

1c. define: sedimentary rock

Answer 3

Rock formed when chemical reactions cement sediments together, hardening them

Question 4

1d. define: igneous rock

Answer 4

rock that forms from molten rock

Question 5

1e. define: metamorphic rock

Answer 5

igneous or sedimentary rock that has been changed into a new kind of rock as a result of great pressure and temperature

Question 6

1f. define : plastic rock

Answer 6

rock that behaves like something between a liquid and a solid

Question 7

1g. define: earthquake

Answer 7

vibration of the earth that results either from volcanic activity or rock masses suddenly moving along a fault

Question 8

1h. define: fault

Answer 8

the boundary between two sections of rock that can move relative to one another

Question 9

1i. define: focus

Answer 9

the point where an earthquake begins

Question 10

1j. define: epicenter

Answer 10

the point on the surface of the earth directly above an earthquake’s focus

Question 11

2. Scientists often separate the earth into five distinct sections. Name those sections

Answer 11

atmosphere, hydrosphere, crust, mantle and core

Question 12

3. Of the five sections listed in problem 2, which can we observe directly?

Answer 12

atmosphere, hydrosphere and crust

Question 13

4. What two regions of the earth does the Moho discontinuity separate? What about the Gutenberg discontinuity? What about the Lehmann discontinuity?

Answer 13

The Moho separates the crust from the mantle, and the Gutenberg discontinuity separates the mantle form the core. The Lehmann discontinuity separates the inner core form the outer core.

Question 14

5. What is the difference between the ways that igneous rock and sedimentary rock form?

Answer 14

Sedimentary rock is formed when sediments

are solidified through chemical reactions. Igneous rock forms when molten rock solidifies.

Question 15

6. Of the three types of rock discussed in this module, which type starts out a different type of rock?

Answer 15

metamorphic rock

Question 16

7. What is unique about the rock in the asthenosphere?

Answer 16

rock behave sometimes like a liquid and sometimes like a solid.

Question 17

8. What is the main thing scientists observe in order to learn about the makeup of the earth’s interior?

Answer 17

scientists observe seismic waves

Question 18

9. Which is solid: the inner core or the outer core? Why is it solid when the other is liquid?

Answer 18

the inner core is solid because of pressure freezing

Question 19

10. Where is the magnetic field of the earth generated?

Answer 19

the magnetic field is generated in the earth’s core

Question 20

11. What causes the magnetic field of the earth?

Answer 20

the magnetic field is caused by a large amount of electrical flow in the core

Question 21

12. Give a brief description of the two main theories that attempt to explain the earth’s magnetic field.

Answer 21

The dynamo theory says that the motion of the core is due to temperature differences in the core and the rotation of the earth. This motion causes the motion of electrical charges in the core, which creates electrical current. The rapid-decay theory states that the electrical current in the core started as a consequence of how the earth formed and is decreasing over time.

Question 22

13. What makes the rapid-decay theory more scientifically valid than the dynamo theory?

Answer 22

The rapid-decay theory has been used to accurately predict the magnetic fields of other planets.

Question 23

14. Why is a catastrophe like the worldwide flood in Noah’s time an essential part of earth’s history if the rapid decay theory is true?

Answer 23

The rapid decay theory requires a global catastrophe in order to be consistent with the data that indicate the magnetic field of the earth has reversed several times.

Question 24

15. What two reasons make otherwise good scientists ignore the more scientifically valid rapid-decay theory?

Answer 24

The fact that the rapid decay theory requires a catastrophe like the worldwide Flood and the fact that the rapid-decay theory indicates an earth 10,000 years old or younger.

Question 25

16. Why would life cease to exist without earth’s magnetic field?

Answer 25

Without the magnetic field, cosmic rays from the sun would hit the earth.

Question 26

17. What are the “plates” in plate tectonics

Answer 26

the plates are large “islands” of the earth’s lithosphere

Question 27

18. What can happen when plates collide with one another?

Answer 27

One plate can slide under another and form a trench; the plates can move away form each other, allowing magma to rise and create new crust; the plates can push against each other, causing the crust to fold; or the plates can slide along each other.

Question 28

19. What is Pangaea?

Answer 28

Pangea is a hypothetical supercontinent that might have existed in earth’s past

Question 29

20. Why do otherwise good scents ignore the plate tectonics theory dispute the evidence that exists for it?

Answer 29

Some good scientists ignore plate tectonics because it is typically linked to the idea of an earth that is billions of years old.

Question 30

21. What causes earthquakes?

Answer 30

Earthquakes are caused by the motion of rock masses along a fault or by volcanic activity.

Question 31

22. Briefly describe the elastic theory of earthquakes.

Answer 31

In the elastic rebound theory, rock masses moving relative to one another get caught on the rough, jagged edges of the fault that lies between them. The rock masses start to bend as they keep trying to have. At some point, the stress becomes too great, and the moving rock breaks free, causing the rock masses on both sides of the fault to snap back to their original shapes. The resulting vibrations are what we feel as an earthquake.

Question 32

23. A seismologist detects an earthquake that measures 4 on the Richter scale. Later, he dectects one that measures 8. How many times more energy does the second earthquake release as compared to the first?

Answer 32

32x32x32x32=1,048,576 times more energy than the first

Question 33

24. Name the four kinds of mountains. What is reqired for the formation of each?

Answer 33

The four types of mountains are: volcanic mountains, domed mountains, fault-block mountains, and folded mountains. Volcanic and domed mountains need magma for the earth’s mantle, fault-block mountains need vertaical motion along a fault, and folded mountains need rock masses pushing against each other.