Question 1

How do geologists determine the Earth's interior temperatures?

Accepted Answer

The physical state and density of materials in the Earth's interior have been determined through the analysis of seismic waves. Laboratory experimentation has enabled geologists to determine the approximate melting point for each of the different types of materials at the specific pressures at which they are found. Knowing the composition, pressure, and melting point of each solid material within the Earth's interior enables geologists to calculate the maximum temperature of that region. Similarly, by using their knowledge of liquid materials, geologists can calculate the minimum temperature of liquid regions of the Earth's interior.

Question 2

The experiment that best simulates pressures of the Earth's core was demonstrated by:

Accepted Answer

A)  high velocity bullets shot into a thin iron film. 
B)  shock waves produced by chemical explosives. 
C)  a diamond- anvil high- pressure cell. 
D)  the hydraulic press. 
A)  high velocity bullets shot into a thin iron film. 
B)  shock waves produced by chemical explosives. 
C)  a diamond- anvil high- pressure cell. 
D)  the hydraulic press. A

Question 3

What is meant by the "Mantle Flush"?

Accepted Answer

It was once believed that the transition zone between the upper and lower mantle was an impenetrable barrier, and that slabs of dense, subducted lithosphere were consumed in the upper mantle. Recent studies using seismic tomography have suggested large accumulations of cold rocks above the mantle transition, substantial patches above the core- mantle boundary, and even a few areas where a cold slab appears to be passing through the transition zone. This 'flush' through the mantle is accompanied by a mantle plume of hot, buoyant material rising to take its place. This upward movement of mantle material may be partly responsible for the breakup of past supercontinents.

Question 4

Reversals in the Earth's magnetic field have probably been caused by:

Accepted Answer

A)  reversals in the polarity of the Sun's magnetic field. 
B)  variations in convection currents in the outer core. 
C)  changes in the direction of tectonic plate movement. 
D)  reversals in the direction of the Earth's rotational axis. 
A)  reversals in the polarity of the Sun's magnetic field. 
B)  variations in convection currents in the outer core. 
C)  changes in the direction of tectonic plate movement. 
D)  reversals in the direction of the Earth's rotational axis.

Question 5

The S- wave shadow zone occurs because:

Accepted Answer

A)  S waves cannot pass through the outer part of the core. 
B)  refraction at the mantle- core boundary bends the S waves 154° away from a straight path. 
C)  reflection at the mantle- core boundary directs the S waves at a 154° angle. 
D)  S waves cannot pass through solids with an extremely high density. 
A)  S waves cannot pass through the outer part of the core. 
B)  refraction at the mantle- core boundary bends the S waves 154° away from a straight path. 
C)  reflection at the mantle- core boundary directs the S waves at a 154° angle. 
D)  S waves cannot pass through solids with an extremely high density.

Question 6

Which of the following statements about the lower mantle is NOT true?

Accepted Answer

A)  The rocks near the base of the lower mantle are more rigid than those near the top of the lower mantle. 
B)  P waves reach a velocity of 13.6 kilometers per second at the base of the mantle. 
C)  The rocks of the lower mantle are most likely magnesium silicates and oxides. 
D)  The lower mantle is solid because its temperatures are lower than those in the asthenosphere. 
A)  The rocks near the base of the lower mantle are more rigid than those near the top of the lower mantle. 
B)  P waves reach a velocity of 13.6 kilometers per second at the base of the mantle. 
C)  The rocks of the lower mantle are most likely magnesium silicates and oxides. 
D)  The lower mantle is solid because its temperatures are lower than those in the asthenosphere.

Question 7

All of the following gravity anomalies could be expected EXCEPT:

Accepted Answer

A)  a negative gravity anomaly over an ocean trench. 
B)  a positive gravity anomaly over subsurface salt deposits. 
C)  a negative gravity anomaly at a continental mountain range. 
D)  a positive gravity anomaly over an ocean basin. 
A)  a negative gravity anomaly over an ocean trench. 
B)  a positive gravity anomaly over subsurface salt deposits. 
C)  a negative gravity anomaly at a continental mountain range. 
D)  a positive gravity anomaly over an ocean basin.

Question 8

Describe the principle of isostasy.

Accepted Answer

Isostasy is the buoyancy equilibrium bet

Question 9

Seismic waves travel in a straight line with constant velocity only when moving:

Accepted Answer

A)  in a homogeneous medium at different temperatures and pressures. 
B)  in a homogenous medium at different temperatures but constant pressures. 
C)  in a homogenous medium at constant temperatures and pressures. 
D)  through media of various compositions at different temperatures and pressures. 
A)  in a homogeneous medium at different temperatures and pressures. 
B)  in a homogenous medium at different temperatures but constant pressures. 
C)  in a homogenous medium at constant temperatures and pressures. 
D)  through media of various compositions at different temperatures and pressures.

Question 10

Briefly explain how we know the structure of the Earth's interior.

Accepted Answer

Most of our knowledge of the Earth's int

Question 11

Because of isostasy, all of the following are true EXCEPT:

Accepted Answer

A)  melting of a continent- wide glacier removes weight from a landmass, causing it to rise. 
B)  the erosion of a mountain peak causes the mountain to rise. 
C)  a dense, massive lava flow causes a landmass to sink lower into the asthenosphere. 
D)  oceanic lithosphere sinks deeper into the asthenosphere than continental lithosphere. 
A)  melting of a continent- wide glacier removes weight from a landmass, causing it to rise. 
B)  the erosion of a mountain peak causes the mountain to rise. 
C)  a dense, massive lava flow causes a landmass to sink lower into the asthenosphere. 
D)  oceanic lithosphere sinks deeper into the asthenosphere than continental lithosphere.

Question 12

The North American mid- continent gravity high marks the location of an ancient:

Accepted Answer

A)  concentration of metallic ore. 
B)  continental rift zone. 
C)  continental suture zone. 
D)  volcanic mountain range. 
A)  concentration of metallic ore. 
B)  continental rift zone. 
C)  continental suture zone. 
D)  volcanic mountain range.

Question 13

The deepest drill hole, located in northern Russia, extends how far into the crust?

Accepted Answer

A)  7 kilometers. 
B)  11 kilometers. 
C)  13 kilometers. 
D)  15 kilometers. 
A)  7 kilometers. 
B)  11 kilometers. 
C)  13 kilometers. 
D)  15 kilometers.

Question 14

The asthenosphere is considered the low- velocity zone because:

Accepted Answer

A)  seismic waves travel more slowly through it than through any other region in the Earth's interior. 
B)  seismic waves travel more slowly through it than through other parts of the mantle. 
C)  in this thin layer of mantle, P- wave velocity is slower than in the crust. 
D)  circulation of material within asthenosphere convection currents moves extremely slowly. 
A)  seismic waves travel more slowly through it than through any other region in the Earth's interior. 
B)  seismic waves travel more slowly through it than through other parts of the mantle. 
C)  in this thin layer of mantle, P- wave velocity is slower than in the crust. 
D)  circulation of material within asthenosphere convection currents moves extremely slowly.

Question 15

Which of the following statements about the Earth's magnetic field is NOT true?

Accepted Answer

A)  The lines of magnetic force are curved and intersect the Earth's surface at various angles. 
B)  Every cubic centimeter of the Earth has lines of magnetic force. 
C)  The magnetic force lines are perpendicular to the surface at the equator and parallel at the poles. 
D)  It completely surrounds the entire Earth and extends far into space. 
A)  The lines of magnetic force are curved and intersect the Earth's surface at various angles. 
B)  Every cubic centimeter of the Earth has lines of magnetic force. 
C)  The magnetic force lines are perpendicular to the surface at the equator and parallel at the poles. 
D)  It completely surrounds the entire Earth and extends far into space.

Question 16

Which of the following statements concerning S waves is NOT true?

Accepted Answer

A)  S waves temporarily displace materials they pass through with a shearing stress. 
B)  The speed of an S wave depends on the elasticity of the media through which it travels. 
C)  S waves may change their direction of travel when they encounter a material of different rigidity. 
D)  S waves do not have enough energy and speed to pass through liquids or gases. 
A)  S waves temporarily displace materials they pass through with a shearing stress. 
B)  The speed of an S wave depends on the elasticity of the media through which it travels. 
C)  S waves may change their direction of travel when they encounter a material of different rigidity. 
D)  S waves do not have enough energy and speed to pass through liquids or gases.

Question 17

In North America, the thinnest crust is only:

Accepted Answer

A)  20- 30 kilometers thick. 
B)  60 kilometers thick. 
C)  70 kilometers thick. 
D)  40- 50 kilometers thick. 
A)  20- 30 kilometers thick. 
B)  60 kilometers thick. 
C)  70 kilometers thick. 
D)  40- 50 kilometers thick.

Question 18

The discovery of the Mohorovišic´ discontinuity (the Moho) was prompted by the observation that:

Accepted Answer

A)  seismic waves that traveled through the mantle reached a seismograph sooner than those that traveled only through the crust. 
B)  seismic waves that traveled through the mantle had to travel farther and arrived at a seismograph later than those that traveled only through the crust. 
C)  seismic waves can travel through the same medium at two different speeds. 
D)  seismic waves that were reflected off the mantle arrived at a seismograph sooner than those that were not reflected off the mantle. 
A)  seismic waves that traveled through the mantle reached a seismograph sooner than those that traveled only through the crust. 
B)  seismic waves that traveled through the mantle had to travel farther and arrived at a seismograph later than those that traveled only through the crust. 
C)  seismic waves can travel through the same medium at two different speeds. 
D)  seismic waves that were reflected off the mantle arrived at a seismograph sooner than those that were not reflected off the mantle.

Question 19

Magnetism is most closely associated with:

Accepted Answer

A)  gravity and the ability of one mass to attract another mass. 
B)  the decay of radioactive atoms, which causes minerals to become magnetized. 
C)  chemical energy and the attraction of atoms during bonding. 
D)  electricity and the movement of electrons. 
A)  gravity and the ability of one mass to attract another mass. 
B)  the decay of radioactive atoms, which causes minerals to become magnetized. 
C)  chemical energy and the attraction of atoms during bonding. 
D)  electricity and the movement of electrons.

Question 20

The location of the thinnest continental crust in North America is located in:

Accepted Answer

A)  Nevada. 
B)  California. 
C)  Iowa. 
D)  North Carolina. 
A)  Nevada. 
B)  California. 
C)  Iowa. 
D)  North Carolina.

How do geologists determine the Earth's interior temperatures?

The experiment that best simulates pressures of the Earth's core was demonstrated by:

What is meant by the "Mantle Flush"?

Reversals in the Earth's magnetic field have probably been caused by:

The S- wave shadow zone occurs because:

Which of the following statements about the lower mantle is NOT true?

All of the following gravity anomalies could be expected EXCEPT:

Describe the principle of isostasy.

Seismic waves travel in a straight line with constant velocity only when moving:

Briefly explain how we know the structure of the Earth's interior.

Because of isostasy, all of the following are true EXCEPT:

The North American mid- continent gravity high marks the location of an ancient:

The deepest drill hole, located in northern Russia, extends how far into the crust?

The asthenosphere is considered the low- velocity zone because:

Which of the following statements about the Earth's magnetic field is NOT true?

Which of the following statements concerning S waves is NOT true?

In North America, the thinnest crust is only:

The discovery of the Mohorovišic´ discontinuity (the Moho) was prompted by the observation that:

Magnetism is most closely associated with:

The location of the thinnest continental crust in North America is located in:

A First Look at Planet Earth - Its Origins, Systems, and Tectonic Plates

Minerals

Igneous Rocks and Processes

Volcanoes and Volcanism

Weathering - the Breakdown of Rocks

Sedimentary Processes, Environments, and Rocks

Metamorphism and Metamorphic Rocks

Telling Time Geologically

Earth Structures - Folds, Faults, and Fabrics

Earthquakes

Plate Tectonics and the Formation of the Earths Oceans

Continental Tectonics and the Formation of the Earths Continents

Mass Movement

Streams and Floods

Groundwater

Glaciers and Ice Ages

Deserts and the Work of Winds

Shores and Coastal Processes

Human Use of the Earths Resources Appendices Glossary

Filters

Exam 11: The Earths Interior - Whats Going on Down There

How do geologists determine the Earth's interior temperatures?

The experiment that best simulates pressures of the Earth's core was demonstrated by:

What is meant by the "Mantle Flush"?

Reversals in the Earth's magnetic field have probably been caused by:

The S- wave shadow zone occurs because:

Which of the following statements about the lower mantle is NOT true?

All of the following gravity anomalies could be expected EXCEPT:

Describe the principle of isostasy.

Seismic waves travel in a straight line with constant velocity only when moving:

Briefly explain how we know the structure of the Earth's interior.

Because of isostasy, all of the following are true EXCEPT:

The North American mid- continent gravity high marks the location of an ancient:

The deepest drill hole, located in northern Russia, extends how far into the crust?

The asthenosphere is considered the low- velocity zone because:

Which of the following statements about the Earth's magnetic field is NOT true?

Which of the following statements concerning S waves is NOT true?

In North America, the thinnest crust is only:

The discovery of the Mohorovišic´ discontinuity (the Moho) was prompted by the observation that:

Magnetism is most closely associated with:

The location of the thinnest continental crust in North America is located in:

A First Look at Planet Earth - Its Origins, Systems, and Tectonic Plates

Minerals

Igneous Rocks and Processes

Volcanoes and Volcanism

Weathering - the Breakdown of Rocks

Sedimentary Processes, Environments, and Rocks

Metamorphism and Metamorphic Rocks

Telling Time Geologically

Earth Structures - Folds, Faults, and Fabrics

Earthquakes

Plate Tectonics and the Formation of the Earths Oceans

Continental Tectonics and the Formation of the Earths Continents

Mass Movement

Streams and Floods

Groundwater

Glaciers and Ice Ages

Deserts and the Work of Winds

Shores and Coastal Processes

Human Use of the Earths Resources Appendices Glossary

Filters