Question 1

Which of the following factors is most influential in causing convection in the outer core?

Accepted Answer

A)  The outer core has a low viscosity, approximately equal to that of water at room temperature. 
B)  The outer core has a high heat conductivity. 
C)  Compositional differences create a difference in density. 
D)  Heating causes expansion of fluids. 
A)  The outer core has a low viscosity, approximately equal to that of water at room temperature. 
B)  The outer core has a high heat conductivity. 
C)  Compositional differences create a difference in density. 
D)  Heating causes expansion of fluids.

Question 2

"What does mantle convection look like?"

Accepted Answer

"Mantle convection explains why heat flo

Question 3

Evaluate the statement. "Convection occurs because of conduction and radiation at the boundaries of a liquid."

Accepted Answer

A)  This statement is true in the laboratory but not true for Earth processes. 
B)  This statement is false because the three types of heat transfer operate separately. 
C)  This statement is true in the laboratory and for Earth processes. 
D)  This statement is false and should say, "Conduction occurs because of convection and radiation at the boundaries of a liquid." 
A)  This statement is true in the laboratory but not true for Earth processes. 
B)  This statement is false because the three types of heat transfer operate separately. 
C)  This statement is true in the laboratory and for Earth processes. 
D)  This statement is false and should say, "Conduction occurs because of convection and radiation at the boundaries of a liquid."

Question 4

Judge the following sentences according to the criteria given below. On average, heat flow through oceanic crust is greater than heat flow through continental crust because mantle heat is transferred towards the surface by convection.

Accepted Answer

A)  The assertion is correct but the reason is incorrect. 
B)  The assertion is incorrect but the reason is correct. 
C)  The assertion and the reason are both correct, and the reason is valid. 
D)  The assertion and the reason are both correct, but the reason is invalid. 
E)  Both the assertion and the reason are incorrect. 
A)  The assertion is correct but the reason is incorrect. 
B)  The assertion is incorrect but the reason is correct. 
C)  The assertion and the reason are both correct, and the reason is valid. 
D)  The assertion and the reason are both correct, but the reason is invalid. 
E)  Both the assertion and the reason are incorrect.

Question 5

Parcels of rising mantle are always ________ than adjacent rocks, and parcels of sinking upper mantle are always ________ than adjacent rocks.

Accepted Answer

A)  more dense; less dense 
B)  heavier; lighter 
C)  warmer; cooler 
D)  more basaltic; less basaltic 
A)  more dense; less dense 
B)  heavier; lighter 
C)  warmer; cooler 
D)  more basaltic; less basaltic

Question 6

Conduction dominates everywhere within the lithosphere.

Accepted Answer

A) True 
 B)False

Question 7

Approximately how long has it been since the last magnetic reversal?

Accepted Answer

A)  1,780 years 
B)  17,800 years 
C)  780,000 years 
D)  1.768 million years 
A)  1,780 years 
B)  17,800 years 
C)  780,000 years 
D)  1.768 million years

Question 8

What occurred to magnetic field strength in Glatzmaier and Roberts' model during polarity reversals?

Accepted Answer

A)  it decreased 
B)  it stayed the same 
C)  it increased 
D)  it disappeared 
A)  it decreased 
B)  it stayed the same 
C)  it increased 
D)  it disappeared

Question 9

The shape of Earth's magnetic field resembles that produced by a laboratory bar magnet.

Accepted Answer

A) True 
 B)False

Question 10

Which property most inhibits convection?

Accepted Answer

A)  elasticity 
B)  viscosity 
C)  density 
D)  rigidity 
A)  elasticity 
B)  viscosity 
C)  density 
D)  rigidity

Question 11

What is the name for a period of time when the magnetic field is oriented in the opposite direction?

Accepted Answer

A)  a magnetic reversal 
B)  a reversed polarity interval 
C)  a normal polarity reversal 
D)  an underage polarity 
A)  a magnetic reversal 
B)  a reversed polarity interval 
C)  a normal polarity reversal 
D)  an underage polarity

Question 12

Judge the following sentences according to the criteria given below. Ice cubes are dropped in a glass of warm water and float to the top. The ice cubes rose to the top of the glass of warm water because the frozen ice is colder than the warm water.

Accepted Answer

A)  The assertion is correct but the reason is incorrect. 
B)  The assertion is incorrect but the reason is correct. 
C)  The assertion and the reason are both correct, and the reason is valid. 
D)  The assertion and the reason are both correct, but the reason is invalid. 
E)  Both the assertion and the reason are incorrect. 
A)  The assertion is correct but the reason is incorrect. 
B)  The assertion is incorrect but the reason is correct. 
C)  The assertion and the reason are both correct, and the reason is valid. 
D)  The assertion and the reason are both correct, but the reason is invalid. 
E)  Both the assertion and the reason are incorrect.

Question 13

The average polarity interval between magnetic reversals over the last 15 million years has been

Accepted Answer

A)  20,000 years. 
B)  200,000 years. 
C)  2,000,000 years. 
D)  2,000 years. 
A)  20,000 years. 
B)  200,000 years. 
C)  2,000,000 years. 
D)  2,000 years.

Question 14

Although we don't know for sure, changes in the strength and orientation of earth's magnetic field are most likely due to

Accepted Answer

A)  fluctuations in outer-core convection. 
B)  variations in sea-floor spreading rates. 
C)  the total number of mantle hot spots. 
D)  changes in the velocity of subducting plates. 
A)  fluctuations in outer-core convection. 
B)  variations in sea-floor spreading rates. 
C)  the total number of mantle hot spots. 
D)  changes in the velocity of subducting plates.

Question 15

Which is not a factor that leads geologists to expect that convection in the mantle is likely?

Accepted Answer

A)  Viscosity in the lithosphere is high. 
B)  Viscosity beneath the lithosphere is lower because the rock is close to its melting temperature. 
C)  Some of the lithosphere is denser than the asthenosphere. 
D)  The thickness and mass of the mantle are huge. 
A)  Viscosity in the lithosphere is high. 
B)  Viscosity beneath the lithosphere is lower because the rock is close to its melting temperature. 
C)  Some of the lithosphere is denser than the asthenosphere. 
D)  The thickness and mass of the mantle are huge.

Question 16

Conduction is the transfer only of heat from hot regions to cold regions.

Accepted Answer

A) True 
 B)False

Question 17

Which statement about the formation of the magnetic field of Earth is true?

Accepted Answer

A)  Its formation is a result of magnetic materials in the core. 
B)  Its formation is a result of the movement of magnetic materials in the core. 
C)  It constantly forms, is lost, and is regenerated. 
D)  It is more strongly observable at relatively low temperatures. 
A)  Its formation is a result of magnetic materials in the core. 
B)  Its formation is a result of the movement of magnetic materials in the core. 
C)  It constantly forms, is lost, and is regenerated. 
D)  It is more strongly observable at relatively low temperatures.

Question 18

Judge the following sentence according to the criteria given below. Earth is long overdue for a magnetic reversal because during the past 15 million years Earth's magnetic field reversed every 200,000 years, on average, and the last reversal was 780,000 years ago.

Accepted Answer

A)  The assertion is correct but the reason is incorrect. 
B)  The assertion is incorrect but the reason is correct. 
C)  The assertion and the reason are both correct, and the reason is valid. 
D)  The assertion and the reason are both correct, but the reason is invalid. 
E)  Both the assertion and the reason are incorrect. 
A)  The assertion is correct but the reason is incorrect. 
B)  The assertion is incorrect but the reason is correct. 
C)  The assertion and the reason are both correct, and the reason is valid. 
D)  The assertion and the reason are both correct, but the reason is invalid. 
E)  Both the assertion and the reason are incorrect.

Question 19

The shape of Earth's magnetic field resembles

Accepted Answer

A)  a bar magnet. 
B)  a horseshoe magnet. 
C)  an elliptical magnet. 
D)  a spherical magnet. 
A)  a bar magnet. 
B)  a horseshoe magnet. 
C)  an elliptical magnet. 
D)  a spherical magnet.

Question 20

What is a possible effect of a magnetic reversal on Earth's organisms?

Accepted Answer

A)  Species become extinct as they lose their navigational ability. 
B)  Organisms are subjected to greater amounts of cosmic radiation. 
C)  Organisms are subjected to greater amounts of radioactivity. 
D)  Organisms will change their habitats with the accompanying climate change. 
A)  Species become extinct as they lose their navigational ability. 
B)  Organisms are subjected to greater amounts of cosmic radiation. 
C)  Organisms are subjected to greater amounts of radioactivity. 
D)  Organisms will change their habitats with the accompanying climate change.

Exam 10: Motion Inside Earth

Which of the following factors is most influential in causing convection in the outer core?

"What does mantle convection look like?"

Evaluate the statement. "Convection occurs because of conduction and radiation at the boundaries of a liquid."

Judge the following sentences according to the criteria given below. On average, heat flow through oceanic crust is greater than heat flow through continental crust because mantle heat is transferred towards the surface by convection.

Parcels of rising mantle are always ________ than adjacent rocks, and parcels of sinking upper mantle are always ________ than adjacent rocks.

Conduction dominates everywhere within the lithosphere.

Approximately how long has it been since the last magnetic reversal?

What occurred to magnetic field strength in Glatzmaier and Roberts' model during polarity reversals?

The shape of Earth's magnetic field resembles that produced by a laboratory bar magnet.

Which property most inhibits convection?

What is the name for a period of time when the magnetic field is oriented in the opposite direction?

Judge the following sentences according to the criteria given below. Ice cubes are dropped in a glass of warm water and float to the top. The ice cubes rose to the top of the glass of warm water because the frozen ice is colder than the warm water.

The average polarity interval between magnetic reversals over the last 15 million years has been

Although we don't know for sure, changes in the strength and orientation of earth's magnetic field are most likely due to

Which is not a factor that leads geologists to expect that convection in the mantle is likely?

Conduction is the transfer only of heat from hot regions to cold regions.

Which statement about the formation of the magnetic field of Earth is true?

Judge the following sentence according to the criteria given below. Earth is long overdue for a magnetic reversal because during the past 15 million years Earth's magnetic field reversed every 200,000 years, on average, and the last reversal was 780,000 years ago.

The shape of Earth's magnetic field resembles

What is a possible effect of a magnetic reversal on Earth's organisms?

Why Study Earth

Minerals: Building Blocks of the Planet

Rocks and Rock-Forming Processes

Formation of Magma and Igneous Rocks

Formation of Sediment and Sedimentary Rocks

Formation of Metamorphic Rocks

Earth Materials As Time Keepers

Earth Materials As Time Keepers

Making Earth

Deformation of Rocks

Global Tectonics: Plates and Plumes

Tectonics and Surface Relief

Soil Formation and Landscape Stability

Mass Movements: Landscapes in Motion

Streams: Flowing Water Shapes the Landscape

Water Flowing Underground

Glaciers: Cold-Climate Sculptors of Continents

Shorelines: Changing Landscapes Where Land Meets Sea

Wind: a Global Geologic Process

Global Warming: Real Time Change in the Earth System

Filters

Parcels of rising mantle are always than adjacent rocks, and parcels of sinking upper mantle are always than adjacent rocks.