Question 1

Geologists infer the interior composition at deep levels from calculations of Earth's density.

Accepted Answer

A) True 
 B)False

Question 2

Choose the option that puts the following steps in the correct sequence. 1. An electric sensor records the signal's travel time. 2. A transducer changes the signal into a thump on the rock. 3. An electrical signal is delivered. 4. The wave travels through the rock.

Accepted Answer

A)  4, 2, 3, 1 
B)  3, 4, 1, 2 
C)  3, 2, 4, 1 
D)  4, 1, 2, 3 
A)  4, 2, 3, 1 
B)  3, 4, 1, 2 
C)  3, 2, 4, 1 
D)  4, 1, 2, 3

Question 3

The Mohorovicic discontinuity or Moho corresponds to the boundary between

Accepted Answer

A)  core and crust. 
B)  mantle and core. 
C)  mantle and crust. 
D)  oceanic crust and continental crust. 
A)  core and crust. 
B)  mantle and core. 
C)  mantle and crust. 
D)  oceanic crust and continental crust.

Question 4

Waves are considered elastic because

Accepted Answer

A)  they bounce back. 
B)  they do not permanently deform the water. 
C)  they are cyclical. 
D)  they do permanently deform the water. 
A)  they bounce back. 
B)  they do not permanently deform the water. 
C)  they are cyclical. 
D)  they do permanently deform the water.

Question 5

What is one additional approach, besides the study of the baseball, that geologists use to gain knowledge about Earth's interior?

Accepted Answer

A)  Geologists infer the interior composition at deep levels from calculations of Earth's density. 
B)  Geologists collect and study data from volcanoes, mainly about the lava, to gain knowledge about the interior. 
C)  Geologists use energy from earthquakes to construct images of Earth's interior. 
D)  Geologists go as far into the center of the earth as possible by exploring in drilled boreholes and mines, going as deep as possible. 
A)  Geologists infer the interior composition at deep levels from calculations of Earth's density. 
B)  Geologists collect and study data from volcanoes, mainly about the lava, to gain knowledge about the interior. 
C)  Geologists use energy from earthquakes to construct images of Earth's interior. 
D)  Geologists go as far into the center of the earth as possible by exploring in drilled boreholes and mines, going as deep as possible.

Question 6

The (P) is (P) waves stands for:

Accepted Answer

A)  physical 
B)  primary 
C)  productive 
D)  pulsing 
A)  physical 
B)  primary 
C)  productive 
D)  pulsing

Question 7

What is the composition of Earth's crust?

Accepted Answer

A)  oceanic: basalt and gabbro; continental: felsic and mafic rocks 
B)  oceanic: basalt; continental: felsic 
C)  oceanic: felsic and mafic rocks; continental: mafic rocks 
D)  oceanic: mafic rocks with some gabbro; continental: felsic rocks with some basalt 
A)  oceanic: basalt and gabbro; continental: felsic and mafic rocks 
B)  oceanic: basalt; continental: felsic 
C)  oceanic: felsic and mafic rocks; continental: mafic rocks 
D)  oceanic: mafic rocks with some gabbro; continental: felsic rocks with some basalt

Question 8

Which factor has the least effect on the shape of the overall geothermal gradient?

Accepted Answer

A)  loss of heat at the surface to the hydrosphere, atmosphere, and space 
B)  increasing temperature with compression of rock at high pressure 
C)  type and composition of rock in the mantle 
D)  heating of the lower mantle by the hotter core 
A)  loss of heat at the surface to the hydrosphere, atmosphere, and space 
B)  increasing temperature with compression of rock at high pressure 
C)  type and composition of rock in the mantle 
D)  heating of the lower mantle by the hotter core

Question 9

At what depth do diamonds form in Earth?

Accepted Answer

A)  3.6 km 
B)  8 km 
C)  50 km 
D)  150 km 
A)  3.6 km 
B)  8 km 
C)  50 km 
D)  150 km

Question 10

Geologists use energy from earthquakes to construct images of Earth's interior.

Accepted Answer

A) True 
 B)False

Question 11

Primary (P) waves have all of the following characteristics except

Accepted Answer

A)  arrives first at seismic stations. 
B)  body wave. 
C)  causes alternating squeezing and stretching of the material as the wave passes. 
D)  can't pass through gases and liquids. 
A)  arrives first at seismic stations. 
B)  body wave. 
C)  causes alternating squeezing and stretching of the material as the wave passes. 
D)  can't pass through gases and liquids.

Question 12

A student comments, "The shadow zone is an area where waves cannot travel because it is a thick layer of liquid at the boundary of the mantle and the outer core." Evaluate this statement.

Accepted Answer

A)  Actually, it was the boundary of the inner core that was discovered with this method. 
B)  It is correct that waves cannot travel in liquid. 
C)  P-waves refract at the shadow zone. S-waves are stopped. 
D)  The shadow zone refers to the whole outer core, not just the boundary. 
A)  Actually, it was the boundary of the inner core that was discovered with this method. 
B)  It is correct that waves cannot travel in liquid. 
C)  P-waves refract at the shadow zone. S-waves are stopped. 
D)  The shadow zone refers to the whole outer core, not just the boundary.

Question 13

How does a seismograph work?

Accepted Answer

A)  Sensitive triggers record digital signals and change them into binary so computers can analyze the data. 
B)  Fluid-filled sensors register shaking signals and feed them to recorders. 
C)  Rotating drums are marked by pens when Earth shakes. 
D)  Infrared movement sensors are wired to an inverter that changes the signals to binary so computers can analyze the data. 
A)  Sensitive triggers record digital signals and change them into binary so computers can analyze the data. 
B)  Fluid-filled sensors register shaking signals and feed them to recorders. 
C)  Rotating drums are marked by pens when Earth shakes. 
D)  Infrared movement sensors are wired to an inverter that changes the signals to binary so computers can analyze the data.

Question 14

What evidence led scientists to believe that waves travel at a greater velocity inside Earth?

Accepted Answer

A)  Studies of earthquake signals via sensors located deep inside drill holes prove it. 
B)  Refraction of energy waves is most efficient at shallower depths. 
C)  Refraction of energy waves is most efficient along short paths. 
D)  Average velocity is faster when the seismograph is farther from the focus of the earthquake. 
A)  Studies of earthquake signals via sensors located deep inside drill holes prove it. 
B)  Refraction of energy waves is most efficient at shallower depths. 
C)  Refraction of energy waves is most efficient along short paths. 
D)  Average velocity is faster when the seismograph is farther from the focus of the earthquake.

Question 15

Which factors pertaining to rock type affect wave velocity through the material?

Accepted Answer

A)  degree of metamorphism and water content 
B)  pressure and density 
C)  mineral abundance and pore space 
D)  temperature and water content 
A)  degree of metamorphism and water content 
B)  pressure and density 
C)  mineral abundance and pore space 
D)  temperature and water content

Question 16

What did Sir Isaac Newton do during the seventeenth century?

Accepted Answer

A)  calculate that a rotating planet would not be perfectly spherical 
B)  determine the mass of Earth 
C)  determine that the Earth has a distinct concentration of high-density material near the center 
D)  use simple surveying and measurements of shadows in sunlight to estimate Earth's size 
A)  calculate that a rotating planet would not be perfectly spherical 
B)  determine the mass of Earth 
C)  determine that the Earth has a distinct concentration of high-density material near the center 
D)  use simple surveying and measurements of shadows in sunlight to estimate Earth's size

Question 17

Which region currently presents the most mysteries to scientists?

Accepted Answer

A)  the low velocity zone in the upper mantle 
B)  the transition zone 
C)  the lowermost mantle 
D)  discontinuities at 410 and 660 km 
A)  the low velocity zone in the upper mantle 
B)  the transition zone 
C)  the lowermost mantle 
D)  discontinuities at 410 and 660 km

Question 18

The focus is the point on the surface directly below the epicenter (location within Earth) of an earthquake.

Accepted Answer

A) True 
 B)False

Question 19

Geologists have not studied the composition of the oceanic crust by

Accepted Answer

A)  dragging buckets along the floor to collect sediment and rocks. 
B)  studying the contents of drill holes. 
C)  examining aboveground mountain ranges. 
D)  analyzing earthquake data. 
A)  dragging buckets along the floor to collect sediment and rocks. 
B)  studying the contents of drill holes. 
C)  examining aboveground mountain ranges. 
D)  analyzing earthquake data.

Question 20

"How fast do seismic waves move through different rocks and under different conditions?"

Accepted Answer

"Waves move very slowly through the air

Exam 8: Earth Materials As Time Keepers

Geologists infer the interior composition at deep levels from calculations of Earth's density.

Choose the option that puts the following steps in the correct sequence. 1. An electric sensor records the signal's travel time. 2. A transducer changes the signal into a thump on the rock. 3. An electrical signal is delivered. 4. The wave travels through the rock.

The Mohorovicic discontinuity or Moho corresponds to the boundary between

Waves are considered elastic because

What is one additional approach, besides the study of the baseball, that geologists use to gain knowledge about Earth's interior?

The (P) is (P) waves stands for:

What is the composition of Earth's crust?

Which factor has the least effect on the shape of the overall geothermal gradient?

At what depth do diamonds form in Earth?

Geologists use energy from earthquakes to construct images of Earth's interior.

Primary (P) waves have all of the following characteristics except

A student comments, "The shadow zone is an area where waves cannot travel because it is a thick layer of liquid at the boundary of the mantle and the outer core." Evaluate this statement.

How does a seismograph work?

What evidence led scientists to believe that waves travel at a greater velocity inside Earth?

Which factors pertaining to rock type affect wave velocity through the material?

What did Sir Isaac Newton do during the seventeenth century?

Which region currently presents the most mysteries to scientists?

The focus is the point on the surface directly below the epicenter (location within Earth) of an earthquake.

Geologists have not studied the composition of the oceanic crust by

"How fast do seismic waves move through different rocks and under different conditions?"

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

Making Earth

Motion Inside 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

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