Deck 3: Earth Structure and Plate Tectonics

Question 1

If P and S waves were to travel at the same constant speeds, what could be inferred about the Earth's interior?

A) The interior is density stratified.
B) The interior is liquid.
C) The interior is homogenous.
D) The interior is solid

Answer 1

C
If the interior of Earth was homogenous, they waves would travel through it at the same speed and in a straight line. Information can be found in the section The Study of Earthquakes Provides Evidence of Layering.

Question 2

Who was responsible for the theory of continental drift?

A) Francis Bacon
B) Sir Ernest Shackleton
C) Alfred Wegener
D) Antonio Snider-Pellegrini

Answer 2

C
Alfred Wegener was a German meteorologist. He proposed the theory of continental drift in 1912 by suggesting that the continents were joined into a single continent at some point. His theory was not accepted because his explanation for a force behind the movement was discredited by some. Information can be found in the section Pieces of Earth's Surface Look Like They Once Fit Together.

Question 3

What did Harry Hess and Robert Dietz suggest the cause of the continents moving was?

A) Convection currents
B) Radioactive decay
C) Conduction
D) Gravity

Answer 3

A
New crust that is being formed moves outwards from the source. Hess and Dietz suggested that new seafloor develops at the Mid-Atlantic Ridge and that this same force causes continents to move as well. The motion would powered by convection currents. Later this hypothesis would be called seafloor spreading. Information can be found in the section The Breakthrough:From Seafloor Spreading to Plate Tectonics.

Question 4

What is an ophiolite a result of?

A) Divergent plate boundaries
B) Portions of continental crust squeezed and sheared onto the face of the continent
C) Parts of oceanic crust obducted onto the edges of continents
D) Continent to continent convergent boundaries

Question 5

What is considered to be the densest type of crust?

A) Basalt
B) Continental crust
C) Granite
D) Andesite

Question 6

What type of plate boundary would continental volcanoes like the Cascade Mountains in the western United States be associated with?

A) Divergent plate boundaries
B) Convergent plate boundaries
C) Transform plate boundaries
D) Rift boundary

Question 7

What process intensified arguments about Earth's age because it would require long periods of time to occur?

A) Uniformitarianism
B) Catastrophism
C) Natural Selection
D) Biblical creation

Question 8

The sustained heat within the Earth's interior is attributed to:

A) Radioactive Decay
B) Conduction
C) Convection
D) Isostatic Equilibrium

Question 9

What keeps Earth's asthenosphere pliable?

A) Chemical composition of the asthenosphere
B) The density of the asthenosphere
C) Earth's internal heat
D) Insulation from the lithosphere

Question 10

What type of wave causes the most damage to property during an earthquake?

A) Primary waves
B) Secondary waves
C) Surface waves
D) Body waves

Question 11

Since the Earth has density stratified layers, which layer would be the densest?

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

Question 12

What hindered the acceptance of the continental drift theory?

A) There was no evidence of tropical plants ever existing in currently cold areas.
B) The explanation of centrifugal effect as the driving force behind the continents moving.
C) The discovery of similar fossils found on different continents.
D) The general shape of the continents.

Question 13

What allowed scientists to confirm their theories that the Earth's interior had layers?

A) A large earthquake that occurred in Alaska
B) A system of 800 seismic stations placed worldwide
C) The correlation between intensity, frequency, and characteristics of waves
D) All of these choices

Question 14

What specifically describes the balance between the lithosphere floating atop the asthenosphere?

A) Buoyancy
B) Isostatic equilibrium
C) Density stratification
D) Compensation

Question 15

What characteristic is associated with convergent plate boundaries?

A) New crust formation
B) Solidification of crust materials
C) Violent geological activity
D) Spreading zones

Question 16

What is not a factor that separates the asthenosphere and the lower mantle into two distinct layers?

A) Temperature
B) Pressure
C) Density
D) Chemical composition

Question 17

Density is defined as:

A) layers that are separated.
B) the speed at which a liquid moves.
C) the weight of a substance.
D) the mass per unit of volume.

Question 18

What features did Dr. Ballard not encounter during his National Geographic exploration to the mid-ocean ridge?

A) the rift valley
B) faults and fractures
C) lava flow
D) tube worms

Question 19

What substance was able to show previous orientations of Earth's magnetic field?

A) Magma
B) Basalt
C) Magnetite
D) Magnesium

Question 20

What was the first evidence that suggested the Earth's crust might be broken into pieces?

A) Echo soundings aboard the Meteor
B) Plotting of deep earthquakes in the Pacific Ring of Fire
C) Radiometric dating
D) Radioactive decay

Question 21

Paleomagnetic data has been used to:

A) measure spreading rates.
B) calibrate the geological time scale.
C) reconstruct continents
D) All of these choices has been determined by paleomagnetic data.

Question 22

Hot spots always occur at plate boundaries.

Question 23

What process involves the radiation of internal heat to the surface?

A) Convection
B) Conduction
C) Radioactive decay
D) Combustion

Question 24

What is the name given to Earth's cool, rigid outer layer based on physical properties?

A) Asthenosphere
B) Core
C) Lithosphere
D) Troposphere

Question 25

How much lithosphere is submerged into the asthenosphere?

A) 10%
B) 30%
C) 70%
D) 90%

Question 26

What prevents the subduction of terranes?

A) The relative thin layer of crusts
B) The low density
C) The proximity from plate boundaries
D) The compression of continental crusts

Question 27

Mountains are supported by the mechanical strength present in the asthenosphere due to the presence of heavy elements such as iron and magnesium.

Question 28

Francis Bacon thought the continents were once joined together, even naming the single continent Pangaea and the surrounding ocean Panthalassa.

Question 29

Ridges, rifts, and rises are common features along divergent plate boundaries.

Question 30

Primary waves travel ____ as fast as secondary waves.

A) half
B) twice
C) three times
D) at the same speed

Question 31

A(n) ____ is a very large column of superheated mantle that originates at the boundary of the core and mantle.

A) Volcano
B) Plume
C) Asthenosphere
D) Ridge

Question 32

Who determined that S waves were unable to survive deep passage through the Earth's interior?

A) Alfred Wegener
B) Richard Oldham
C) Inge Lehmann
D) Francis Bacon

Question 33

Radiometric dating was used to age the ocean floor which was found to be older than the land at the center of continents.

Question 34

Convection occurs when heat rises which changes the density of a fluid or semisolid substance.

Question 35

What evidence did James Hutton use to discount the biblical account of the Creation of Earth?

A) The erosion rates of streambeds
B) The distribution of sediments in rivers
C) The patterns of rocks found in the countryside
D) All of these choices

Question 36

The mantle is the largest layer in terms of mass and volume.

Question 37

The Earth's core only effects S wave behavior.

Question 38

The rate of convergence and divergence is approximately the same worldwide.

Question 39

Why do transform faults form?

A) They form due to remnants of convergent boundaries.
B) They form as results of secondary seismic waves.
C) They form due to lithospheric plate subduction zones.
D) They form because the axis of seafloor spreading across the surface of the Earth cannot follow a straight line smoothly.

Question 40

The spreading ridges are almost devoid of free sediment especially compared to basins.

Question 41

What is seafloor spreading and plate tectonics? How does seafloor spreading and plate tectonics connect previous theories of the movement of continents?

Question 42

Transform plate boundaries are not involved in the creation or destruction of crust, rather the plates just move past one another.

Question 43

Paleomagnetism was the confirmation needed to show historical plate movements.

Question 44

What is paleomagnetism? Why have magnetometers shown symmetrical bands of magnetism strength at varying locations?

Question 45

Surface waves are used to analyze the Earth's interior structure.

Question 46

Earthquakes are generated by two types of low frequency waves.

Question 47

Discuss the composition and characteristics of Earth's layers. How was the composition of the mantle and core determined?

Question 48

Despite the various attempts of land and ocean drilling, there has been no success in reaching the interior of the Earth.

Question 49

What were the various theories about the age of the Earth? How did these theories lead to advances in science and new discoveries?

Question 50

What was Alfred Wegener's theory of continental drift? What evidence did he have to support his theory? Why was his theory originally rejected?