Deck 7: Earthquakes and the Earths Structure

Question 1

__________ is the study of earthquakes and the nature of Earth's interior based on elastic waves traveling through rock, produced by an earthquake.

A) Seismology
B) Cosmology
C) Seismicity
D) Ecology

Answer 1

A

Question 2

A/an __________ is a sea wave generated by an underwater earthquake.

Answer 2

tsunami

Question 3

The initial rupture point of an earthquake is the __________.

Answer 3

focus

Question 4

When rock retains its new shape (without fracturing) after stress has been removed, it has undergone __________ __________.

Question 5

A type of continuous, snail-like rock movement that occurs along parts of the San Andreas Fault is called __________ __________.

Question 6

A rock that has deformed __________ under stress keeps its new shape when the stress is released.

A) elastically
B) non-permanently
C) plastically
D) flexibly

Question 7

__________ are small earthquakes that precede a large quake by an interval ranging from a few seconds to a few weeks.

Question 8

Earthquakes are detected and measured with a device called a/an _____________.

Question 9

The initial rupture point of an earthquake (below Earth's surface) is the __________.

A) focus
B) disaster zone
C) releaser
D) epicenter

Question 10

The boundary between the crust and the mantle is called the __________ __________.

Question 11

__________ __________ are body waves that move much more slowly than P waves.

Question 12

The total amount of energy released during an earthquake, calculated from the amount of movement and the surface area of a fault, is measured by the _________? __________ scale.

Question 13

Earthquakes occur along the upper portion of a sinking plate in the __________ zone.

Question 14

__________ __________ are body waves that can travel through air, liquid, and solid material.

Question 15

The metallic core is composed of __________ and __________.

Question 16

When a wave passes from one medium into another, it refracts and sometimes __________.

Question 17

Surface waves radiate from the __________ along the Earth's surface.

Question 18

A/an __________ is a sudden motion or trembling of the Earth.

Question 19

The __________ is located on Earth's surface directly above the initial rupture point of an earthquake.

A) fault
B) upper center
C) focus
D) epicenter

Question 20

__________ waves are elastic waves traveling through rock, produced by an earthquake.

A) Tidal
B) Seismic
C) Electromagnetic
D) Ocean

Question 21

The Mercalli scale measures:

A) numbers of earthquake waves generated.
B) the intensity of an earthquake based on its destructive power.
C) the amount of energy released during an earthquake based on the largest recorded body wave.
D) the amount of energy released during an earthquake based on the amount of movement and fault area.

Question 22

The San Andreas Fault zone is an example of a/an:

A) earthquake zone at a transform plate boundary.
B) Benioff zone.
C) earthquake zone at a subduction plate boundary.
D) earthquake at a divergent plate boundary.

Question 23

__________ waves are the fastest body waves generated by an earthquake.

A) P
B) Q
C) R
D) S

Question 24

Earthquakes occur primarily along plate boundaries because:

A) igneous activity produces all earthquakes.
B) the crust is plastic and flows easily.
C) rock fractures at moving plate boundaries releasing energy.
D) tidal forces are concentrated here.

Question 25

When energy from stress is used to deform rock and give it a permanent new shape, such as a fold, this process is called:

A) elastic deformation.
B) fracture.
C) plastic deformation.
D) slippage.

Question 26

The moment magnitude scale:

A) is based on the highest peak recorded on a specific type of seismograph.
B) can be used to locate the earthquake epicenter.
C) is an accurate indicator of the energy released during an earthquake.
D) is measured by recording the amount of structural damage in an area.

Question 27

The __________ scale measures the total amount of energy released during an earthquake, based on the amount of movement and the fault surface area.

A) Mercalli
B) Roncalli
C) Richter
D) moment magnitude

Question 28

A Benioff zone is an earthquake zone at a __________ plate boundary

A) transform
B) subduction (convergent)
C) divergent
D) rifting

Question 29

During the process of __________, soil loses its shear strength and becomes a fluid.

A) liquefaction
B) liquidation
C) subduction
D) fault creeping

Question 30

The Mohorovicic discontinuity is the boundary between __________ and __________.

A) crust, mantle
B) mantle, outer core
C) outer core, inner core
D) continental crust, oceanic crust

Question 31

A seismograph measures __________.

A) Earth's temperature
B) magnetic anomalies
C) ground vibrations
D) isostasy

Question 32

When solid rock deforms and returns to its original shape, it has undergone:

A) elastic deformation.
B) plastic deformation.
C) liquefaction.
D) brittle fracture.

Question 33

A strike-slip fault is a __________ fault on which rocks on opposite sides move __________.

A) vertical, horizontally
B) vertical, vertically
C) horizontal, vertically
D) horizontal, horizontally

Question 34

To measure the distance from a recording station to an earthquake epicenter, geologists evaluate the __________ with a time-travel curve.

A) magnitude of an earthquake
B) refraction of P and S waves
C) amplitude of the largest earthquake waves
D) interval between the arrival of P and S waves

Question 35

__________ is a continuous, slow movement of solid rock along a fault, usually not causing large earthquakes.

A) Fracturing
B) Fault slipping
C) Fault creep
D) Strike-slip

Question 36

S, or shear, waves:

A) are faster than P waves.
B) move through solids, liquids, and gases.
C) move along the Earth's surface only.
D) are characterized by particle movement perpendicular to direction of wave propagation.

Question 37

Earthquakes occur repeatedly along established faults because:

A) they are over a spreading center.
B) when tectonic stress builds, the rock is more likely to move along the fault than to crack again and create a new fault.
C) they are occurring slowly and continuously at a subduction zone.
D) they occur at plate interiors.

Question 38

P, or primary, waves:

A) are characterized by alternate compression and expansion of rock.
B) are the slowest waves generated by an earthquake.
C) pass through liquids only.
D) move along the Earth's surface only.

Question 39

P waves and S waves:

A) move along the Earth's surface only.
B) travel through Earth's interior.
C) do not reflect and refract at boundaries.
D) have very high amplitudes compared to surface waves.

Question 40

Geologists learned that the outer core is liquid because __________ do not travel through the outer core.

A) surface waves
B) tsunamis
C) P waves
D) S waves
Multiple Choice

Question 41

Where two tectonic plates move past one another, rock near the plate boundary can stretch or compress elastically for decades, and then fracture suddenly and create an earthquake.

Question 42

Earthquakes occur along the Mid-Oceanic Ridge because:

A) blocks of oceanic crust drop downward as the rift valley opens.
B) two plates slip horizontally past one another.
C) the subducting plate scrapes along the lower crust.
D) large submarine landslides occur on the landward edge of the subduction zone.

Question 43

P waves in the Earth travel more than ten times slower than the speed of sound in air.

Question 44

Moment magnitude most closely reflects the total amount of energy released during an earthquake.

Question 45

The San Andreas Fault zone is located at a transform plate boundary.

Question 46

A seismogram records Earth vibrations.

Question 47

The Mercalli scale expresses the amount of energy released by an earthquake.

Question 48

The likely source of the Earth's magnetism is:

A) the flow of liquid metals in the outer core.
B) a permanent magnet within the Earth's core.
C) the Sun.
D) convection currents in the mantle.
True/False

Question 49

Only deep earthquakes occur along the Mid-Oceanic Ridge.

Question 50

It is sometimes possible to predict a large earthquake a few seconds before a building begins to shake and topple.

Question 51

The Mohorovicic discontinuity is the boundary between the outer and inner core.

Question 52

Earthquakes never occur in plate interiors.

Question 53

The earthquakes caused when a subducting plate sinks into the mantle:

A) concentrate along the upper portion of the sinking plate.
B) concentrate in the asthenosphere adjacent to the sinking plate.
C) are very shallow earthquakes.
D) occur only at the same time as volcanic eruptions.

Question 54

No S waves pass through the center of the Earth because:

A) the crust absorbs all waves.
B) the outer core is liquid.
C) S waves travel only through liquids.
D) S waves are compressional waves.

Question 55

P and S waves travel more rapidly in the crust than they do in the mantle below the asthenosphere.

Question 56

In liquefaction, the soil loses its shear strength and becomes a solid.

Question 57

During fault creep:

A) rapid and sudden movement along a fault occurs, usually causing large earthquakes.
B) rapid and sudden movement along a fault occurs, usually not causing large earthquakes.
C) a continuous, slow movement along a fault occurs, usually causing large earthquakes.
D) a continuous, slow movement along a fault occurs, usually not causing large earthquakes.

Question 58

Primary waves travel more slowly than either type of body wave.

Question 59

P and S waves travel through all types of material.

Question 60

A tsunami, produced by an undersea earthquake, may travel at 750 kilometers per hour.