Question 1

The graph below shows that in general P-wave velocities ________ as they travel through the mantle.

Accepted Answer

A) slow down 
B) stay the same 
C) speed up 
D) go to zero 
A) slow down 
B) stay the same 
C) speed up 
D) go to zero B

Question 2

If a P-wave is traveling through Earth and encounters a molten magma chamber,what will happen to the velocity of the P-wave?

Accepted Answer

A) It will slow down. 
B) It will speed up. 
C) It will stay at the same speed. 
D) It will drop to zero. 
A) It will slow down. 
B) It will speed up. 
C) It will stay at the same speed. 
D) It will drop to zero. A

Question 3

The time it takes for a seismic wave to travel from the focus to a seismometer is called the ________.

Accepted Answer

A) wave front time 
B) P-S wave arrival distance 
C) travel time 
D) seismic ray time 
A) wave front time 
B) P-S wave arrival distance 
C) travel time 
D) seismic ray time C

Question 4

Which layer of Earth has the highest density?

Accepted Answer

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

Question 5

If a P-wave is traveling from a layer of mantle peridotite to a layer of limestone crust,what will happen to the P-wave in terms of speed and direction of motion?

Accepted Answer

The P-wave will slow

Question 6

Seismic waves ________ when they move from the crust into the mantle.

Accepted Answer

A) speed up 
B) slow down 
C) reverse direction 
D) are not affected 
A) speed up 
B) slow down 
C) reverse direction 
D) are not affected

Question 7

Seismic waves travel ________ in solids than in liquids;however,unlike P-waves,S-waves ________ travel through liquids.

Accepted Answer

A) slower;can 
B) slower;cannot 
C) faster;can 
D) faster;cannot 
A) slower;can 
B) slower;cannot 
C) faster;can 
D) faster;cannot

Question 8

Why does a mountain show a positive gravity anomaly?

Accepted Answer

The mountain contains a large

Question 9

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 the crust being pulled into the trench is less dense than 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 
A) because the bathymetry of the trench dips very far below sea level 
B) because the crust being pulled into the trench is less dense than 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 10

The absence of ________ can indicate the presence of magma in the crust.

Accepted Answer

A) P-waves 
B) S-waves 
C) surface waves 
D) body waves 
A) P-waves 
B) S-waves 
C) surface waves 
D) body waves

Question 11

Using the image below,explain why Ray M arrives at the seismometer before Ray C.

Accepted Answer

Ray C travels within the crust,which has

Question 12

If you measure the magnetization of an area of igneous rocks and find a large negative anomaly,what does that imply about the rocks?

Accepted Answer

A) They were formed during a time of normal polarity of the magnetic field. 
B) They were formed during a time of reversed polarity of the magnetic field. 
C) They were formed on the ocean floor where the rocks are closer to the core. 
D) They were formed on the continental crust in a complex pattern of magnetization. 
A) They were formed during a time of normal polarity of the magnetic field. 
B) They were formed during a time of reversed polarity of the magnetic field. 
C) They were formed on the ocean floor where the rocks are closer to the core. 
D) They were formed on the continental crust in a complex pattern of magnetization.

Question 13

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. 
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 14

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

Question 15

Why does Earth have a magnetic field?

Accepted Answer

A) Because all planets have magnetic fields that were created during the early formation of the solar system. 
B) Because Earth's inner core behaves like a permanent magnet and produces the magnetic field. 
C) Because the motion of the plates generates an electric current that produces the magnetic field. 
D) Because early in Earth's history the outer core behaved like a moving wire coil in an external magnetic field and produced Earth's magnetic field. 
A) Because all planets have magnetic fields that were created during the early formation of the solar system. 
B) Because Earth's inner core behaves like a permanent magnet and produces the magnetic field. 
C) Because the motion of the plates generates an electric current that produces the magnetic field. 
D) Because early in Earth's history the outer core behaved like a moving wire coil in an external magnetic field and produced Earth's magnetic field.

Question 16

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

Question 17

In the picture below,when the ship is filled with cargo it sinks into the water until the mass of water displaced is equal to the mass of the cargo.The ship is then said to be ________.

Accepted Answer

A) an equipotential surface 
B) a self-exciting dynamo 
C) equal to the geoid 
D) in isostatic equilibrium 
A) an equipotential surface 
B) a self-exciting dynamo 
C) equal to the geoid 
D) in isostatic equilibrium

Question 18

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

Accepted Answer

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

Question 19

The core-mantle boundary was first discovered when seismologists noticed a(n)________ on the opposite side of Earth.

Accepted Answer

A) seismic discontinuity 
B) low velocity zone 
C) S-wave shadow 
D) P-wave shadow 
A) seismic discontinuity 
B) low velocity zone 
C) S-wave shadow 
D) P-wave shadow

Question 20

Why is Earth's gravitational field NOT smooth?

Accepted Answer

A) Gravitational fields are never smooth due to changes in the shape of the planets. 
B) Earth is close to the Sun,which pulls on the gravitational field and causes it to be misshapen. 
C) The density of materials on Earth is not uniform and the surface contains changes in topography. 
D) The gravitational field is much lower for any area that is covered in water and thus is different over land versus water. 
A) Gravitational fields are never smooth due to changes in the shape of the planets. 
B) Earth is close to the Sun,which pulls on the gravitational field and causes it to be misshapen. 
C) The density of materials on Earth is not uniform and the surface contains changes in topography. 
D) The gravitational field is much lower for any area that is covered in water and thus is different over land versus water.

Exam 23: Interlude D: The Earth S Interior Revisited: Insights From Geophysics

The graph below shows that in general P-wave velocities ________ as they travel through the mantle.

If a P-wave is traveling through Earth and encounters a molten magma chamber,what will happen to the velocity of the P-wave?

The time it takes for a seismic wave to travel from the focus to a seismometer is called the ________.

Which layer of Earth has the highest density?

If a P-wave is traveling from a layer of mantle peridotite to a layer of limestone crust,what will happen to the P-wave in terms of speed and direction of motion?

Seismic waves ________ when they move from the crust into the mantle.

Seismic waves travel ________ in solids than in liquids;however,unlike P-waves,S-waves ________ travel through liquids.

Why does a mountain show a positive gravity anomaly?

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

The absence of ________ can indicate the presence of magma in the crust.

Using the image below,explain why Ray M arrives at the seismometer before Ray C.

If you measure the magnetization of an area of igneous rocks and find a large negative anomaly,what does that imply about the rocks?

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

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

Why does Earth have a magnetic field?

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

In the picture below,when the ship is filled with cargo it sinks into the water until the mass of water displaced is equal to the mass of the cargo.The ship is then said to be ________.

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

The core-mantle boundary was first discovered when seismologists noticed a(n)________ on the opposite side of Earth.

Why is Earth's gravitational field NOT smooth?

The Earth in Context

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

The Wrath of Vulcan: Volcanic Eruptions

Pages of Earth S Past: Sedimentary Rocks

Metamorphism: A Process of Change

A Violent Pulse: Earthquakes

Crags, cracks, and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of Earth

Riches in Rock: Energy and Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Streams and Floods: The Geology of Running Water

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

Dry Regions: The Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Interlude A: Rock Groups

Interlude B: A Surface Veneer: Sediments and Soils

Interlude C: The Rock Cycle

Interlude E: Memories of Past Life: Fossils and Evolution

Interlude F: An Introduction to Landscapes and the Hydrologic Cycle

Filters

Seismic waves travel in solids than in liquids;however,unlike P-waves,S-waves travel through liquids.

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