Question 1

What causes the velocity of a P-wave to slow down when it enters the outer core?

Accepted Answer

A)   The outer core is a much more dense material than the mantle.
B)   The outer core is a much less dense material than the mantle.
C)   The outer core is liquid, and thus the wave slows down.
D)   The P-wave no longer has to compete with the S-wave for energy. D

Question 2

If a P-wave is traveling through sandstone and then encounters peridotite,the P-wave will ________________.

Accepted Answer

A)   slow down
B)   speed up
C)   remain at the same speed
D)   not travel through the peridotite

Question 3

The picture below shows a seismic tomography image of the western United States.What is the relative temperature of the blue regions (darker grey regions not outlined in black) versus the red regions (darker grey regions outlined in black) ?

Accepted Answer

A)   The blue regions are warmer than the red regions.
B)   The red regions are colder than the blue regions.
C)   The red regions are warmer than the blue regions.
D)   The colors are not indicative of temperature, only velocity.

Question 4

Earth's magnetic field is produced in the ___________.

Accepted Answer

A)   crust
B)   mantle
C)   outer core
D)   inner core

Question 5

If a seismic wave is refracted upward at a boundary,what can be said about the material the wave is traveling through?

Accepted Answer

A)   The wave is moving through two materials of the same velocity.
B)   The wave is moving from a faster material into a slower material.
C)   The wave is moving from a slower material into a faster material.
D)   The wave is traveling through a molten magma chamber.

Question 6

If a ship towing a magnetometer passes over a piece of crust with a "normal" polarity,what will the magnetic anomaly look like?

Accepted Answer

A)   The magnetic anomaly will be greater than Earth's.
B)   The magnetic anomaly will be lower than Earth's.
C)   The magnetic anomaly will exactly match Earth's.
D)   The magnetic anomaly will be exactly zero.

Question 7

In the seismic tomography cross section below,where is the subducting Juan de Fuca Plate,considering that the subducting plate is much cooler than the surrounding material?

Accepted Answer

A)   #4: blue blob at the far right side of the picture that extends straight down into the image
B)   #2: blue blob at the left side of the picture that extends down at an angle into the image
C)   #1: red blob at the far left side of the picture that extends straight down into the image
D)   #3: red blob in the center of the picture that extends straight down into the image

Question 8

Why are magnetic anomalies of continental crust so much more complicated than those of oceanic crust?

Accepted Answer

A)   The continents are much older and thus have had more time for the minerals to become magnetized.
B)   The continents contain abundant iron minerals, whereas the oceanic crust does not contain any iron minerals.
C)   The continents contain a random orientation of minerals that become magnetized when they interact with the magnetic field.
D)   The continents contain a complex distribution of igneous intrusions, lava flows, and iron-rich sediments. D

Question 9

In the following graph,why does the line for S-waves NOT appear in the outer core?

Accepted Answer

A)   S-waves can't travel through the outer core because it is solid.
B)   S-waves can't travel through the outer core because it is liquid.
C)   S-waves disappear after being reflected at the core-mantle boundary.
D)   S-waves can't travel that far into the Earth due to the high amount of iron.

Question 10

Earth's gravity is best represented by an equipotential surface that contains bumps and depressions where areas of more or less gravity appear over the Earth,this representation is called the _________.

Accepted Answer

A)   reference geoid
B)   gravitational potential
C)   isostasy
D)   geoid

Question 11

S-waves travel ________ than P-waves; however,unlike P-waves,they _______ travel through liquids.

Accepted Answer

A)   slower; can
B)   slower; can't
C)   faster; can
D)   faster; can't

Question 12

Why would the gravity anomaly over a deep-ocean trench be negative?

Accepted Answer

A)   because the bathymetry of the trench dips very far below sea level
B)   because dense crust is being pulled into the trench, leaving less dense sediments above
C)   because water fills the space above the subducting slab and is much less dense than rock
D)   because the buoyant magma created at the subduction zones is less dense than the rock

Question 13

You are studying the seismic data from Mars when you notice that there are no S-waves recorded from 130° through 180° on the opposite side of the planet.What does this information tell you about the interior of Mars?

Accepted Answer

A)   There is a layer of solid material in the interior of Mars.
B)   There is a layer of liquid material in the interior of Mars.
C)   There is a layer with a higher velocity material than the crust below.
D)   There is a layer with a lower velocity material than the crust below.

Question 14

The core consists of two layers: the ______ inner core and ______ outer core.

Accepted Answer

A)   iron; nickel
B)   nickel; iron
C)   solid; liquid
D)   liquid; solid

Question 15

If a gravity anomaly is negative,what does that imply about the material underground?

Accepted Answer

A)   The material is much more dense rock.
B)   The material is much less dense rock.
C)   The material is an underground ore.
D)   The material is composed of mantle.

Question 16

If an S-wave is traveling through rock when it encounters a magma chamber,the S-wave will ________________.

Accepted Answer

A)   slow down
B)   speed up
C)   remain at the same speed
D)   not travel through the magma

Question 17

Geophysics is the study of _________.

Accepted Answer

A)   how magma moves within the Earth
B)   how Earth's layers change through time
C)   the interior of Earth using seismicity, magnetics, and gravity
D)   the surface of Earth using seismicity, magnetics, and gravity

Question 18

A positive magnetic anomaly is produced when the measured magnetic field strength is ___________ the expected magnetic field strength.

Accepted Answer

A)   greater than
B)   less than
C)   the same as
D)   the opposite of

Question 19

A mountain range made of granite would produce a(n) _____________ gravity anomaly.

Accepted Answer

A)   positive
B)   negative
C)   isostatic
D)   magnetized

Question 20

The following picture is that of a gravity map of the United States.What do the dark grey regions mean in terms of the density of the material below?

Accepted Answer

A)   high-density rock
B)   low-density rock
C)   rock of high magnetization
D)   rock of low magnetization A

Exam 23: The Earths Interior Revisited: Insights From Geophysics

What causes the velocity of a P-wave to slow down when it enters the outer core?

Correct AnswerverifiedD

If a P-wave is traveling through sandstone and then encounters peridotite,the P-wave will ________________.

Correct AnswerverifiedShow Answer

The picture below shows a seismic tomography image of the western United States.What is the relative temperature of the blue regions (darker grey regions not outlined in black) versus the red regions (darker grey regions outlined in black) ?

Correct AnswerverifiedShow Answer

Earth's magnetic field is produced in the ___________.

Correct AnswerverifiedShow Answer

If a seismic wave is refracted upward at a boundary,what can be said about the material the wave is traveling through?

Correct AnswerverifiedShow Answer

If a ship towing a magnetometer passes over a piece of crust with a "normal" polarity,what will the magnetic anomaly look like?

Correct AnswerverifiedShow Answer

In the seismic tomography cross section below,where is the subducting Juan de Fuca Plate,considering that the subducting plate is much cooler than the surrounding material?

Correct AnswerverifiedShow Answer

Why are magnetic anomalies of continental crust so much more complicated than those of oceanic crust?

Correct AnswerverifiedD

In the following graph,why does the line for S-waves NOT appear in the outer core?

Correct AnswerverifiedShow Answer

Earth's gravity is best represented by an equipotential surface that contains bumps and depressions where areas of more or less gravity appear over the Earth,this representation is called the _________.

Correct AnswerverifiedShow Answer

S-waves travel ________ than P-waves; however,unlike P-waves,they _______ travel through liquids.

Correct AnswerverifiedShow Answer

Why would the gravity anomaly over a deep-ocean trench be negative?

Correct AnswerverifiedShow Answer

You are studying the seismic data from Mars when you notice that there are no S-waves recorded from 130° through 180° on the opposite side of the planet.What does this information tell you about the interior of Mars?

Correct AnswerverifiedShow Answer

The core consists of two layers: the ______ inner core and ______ outer core.

Correct AnswerverifiedShow Answer

If a gravity anomaly is negative,what does that imply about the material underground?

Correct AnswerverifiedShow Answer

If an S-wave is traveling through rock when it encounters a magma chamber,the S-wave will ________________.

Correct AnswerverifiedShow Answer

Geophysics is the study of _________.

Correct AnswerverifiedShow Answer

A positive magnetic anomaly is produced when the measured magnetic field strength is ___________ the expected magnetic field strength.

Correct AnswerverifiedShow Answer

A mountain range made of granite would produce a(n) _____________ gravity anomaly.

Correct AnswerverifiedShow Answer

The following picture is that of a gravity map of the United States.What do the dark grey regions mean in terms of the density of the material below?

Correct AnswerverifiedA

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D

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S-waves travel __ than P-waves; however,unlike P-waves,they _ travel through liquids.

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The core consists of two layers: the inner core and outer core.

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