Deck 9: Earthquakes and Earths Interior

Question 1

is the maximum possible damage designation on the Mercalli scale.

A)XII
B)10
C)X
D)12

Answer 1

A

Question 2

The mechanism by which rocks store and eventually release energy in the form of an earthquake is termed .

A)fault displacement
B)stress fracture
C)elastic rebound
D)seismic rebound

Answer 2

C

Question 3

The earthquake was accompanied by extensive fire damage.

A)San Francisco, 1906
B)Yerevan, Armenia, 1988
C)Anchorage, 1964
D)Mexico City, 1985

Answer 3

A

Question 4

The distance between a seismological recording station and the earthquake source is determined from the .

A)arrival times of P and S waves
B)length of the seismic record
C)intensity of the earthquake
D)earthquake magnitude

Question 5

The lithosphere is defined as .

A)a rigid layer of crustal and mantle material
B)a rocky layer composed mainly of crustal rocks
C)a plastic layer composed mainly of mantle material
D)a rocky layer having a relatively uniform chemical composition

Question 6

P waves _ .

A)have higher amplitudes than do S waves
B)produce the strongest ground shaking
C)propagate only in solids
D)are faster than S waves and surface waves

Question 7

Most of our knowledge about Earth's interior comes from .

A)examination of deep mine shafts
B)drill holes
C)seismic waves
D)volcanic eruptions

Question 8

The position on Earth's surface directly above the earthquake source is called the .

A)inertial point
B)focus
C)epicenter
D)seismic zone

Question 9

refers to the tendency for a foundation material to lose its internal cohesion and fail mechanically during earthquake shaking.

A)Seismoflowage
B)Slurrying
C)Motion slip
D)Liquefaction

Question 10

Which one of the following statements is correct?

A)S waves travel through solids and P waves travel through liquids.
B)P and S waves travel through liquids, but S waves do not travel through solids.
C)P waves travel through solids; S waves do not.
D)P and S waves travel through liquids, but P waves do not travel through solids.

Question 11

Major earthquakes are often followed by somewhat smaller events known as .

A)hyposhocks
B)tremors
C)foreshocks
D)aftershocks

Question 12

Overall, this type of seismic wave is the most destructive.

A)S wave
B)tsunami
C)surface wave
D)P wave

Question 13

The instrument that records earthquake events is termed a _.

A)polygraph
B)seismograph
C)barograph
D)thermograph

Question 14

The Richter magnitude of an earthquake is determined from the .

A)amplitude of the surface waves
B)intensity of the earthquake
C)arrival time of P and S waves
D)duration of the earthquake

Question 15

When an earthquake occurs, energy radiates in all directions from its source. The source is also referred to as the .

A)focus
B)epicenter
C)seismic zone
D)inertial point

Question 16

Approximately how much more energy is released in a 6.5 Moment Magnitude earthquake than in one with Mw of 5.5?

A)3000 times
B)300 times
C)30 times
D)3 times

Question 17

Which one of the following best characterizes tsunamis?

A)They have relatively small amplitudes compared to their very long wavelengths.
B)They are easily seen at sea but are lost in the swell and breaking waves along a coast.
C)They are faster than seismic surface waves.
D)They cause the land to ripple and oscillate.

Question 18

The dense core of Earth is thought to consist predominantly of _ .

A)iron
B)copper
C)nickel
D)lead

Question 19

Which one of the following is TRUE regarding tsunamis?

A)They occur in the open ocean, wavelengths are many miles or kilometers and wave heights are only a few feet.
B)They are started by fault- induced, horizontal shifts in the seafloor that suddenly propel great masses of water in opposite directions.
C)They travel as deep- water waves at speeds greater than surface seismic waves but slower than S waves.
D)Their wave heights decrease and wavelengths increase as they move into shallower water.

Question 20

The average composition of the oceanic crust is thought to approximate that of .

A)granite
B)peridotite
C)basalt
D)iron

Question 21

The amount of destruction caused by earthquake vibrations is affected by .

A)intensity and duration of the vibrations
B)design of structures
C)nature of the surface material
D)all of these

Question 22

Since much of our knowledge of Earth's interior is inferred from the behavior of seismic waves and not actual samples, what are some of the assumptions that are made in order for our models to be correct? (Hint: Think of earth materials, physical and chemical parameters, etc.)

Question 23

The Mercalli Scale is a scale from .

A)I to X that rates the total energy released during the main quake and all aftershocks
B)I to XII that rates the structural damage due to an earthquake
C)1 to 10 that rates the energy released by an earthquake
D)1 to 12 that rates the energy required for faulting to occur

Question 24

On a typical seismogram, will show the highest amplitudes.

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

Question 25

What instrument is used to record earthquake vibrations?

Question 26

is the layer of warm rock below the crust and uppermost mantle that readily deforms and flows plastically.

Question 27

The record of an earthquake obtained from a seismic instrument is a(n).

A)seismogram
B)epigraph
C)seismograph
D)time- travel graph

Question 28

is the cool, brittle, outer layer of Earth that includes the crust and uppermost mantle.

Question 29

have the highest velocities.

A)Primary waves
B)Secondary waves
C)Refracted S waves
D)Surface waves

Question 30

What is thought to be the material state (liquid, solid, gas)and elemental composition of Earth's outer core?

Question 31

The elastic rebound theory for the origin of earthquakes was first proposed by following the earthquake.

A)Mohorovicic; 1964 Anchorage
B)Reid; 1906 San Francisco
C)Richter; 1989 Loma Prieta
D)Giuseppe; 1925 Pizza Lake

Question 32

The is the site of initial rupturing associated with an earthquake.

Question 33

The average composition of the continental crust most closely approximates that of _ _.

A)peridotite
B)basalt
C)iron
D)granite

Question 34

The Magnitude is a measure of the total energy released. It does not directly measure the extent of building damage.

A)Mercalli
B)Reid
C)Moment
D)Gutenberg

Question 35

is the name of the earthquake- magnitude scale based on the amount of total energy released during a large earthquake.

Question 36

Which one of the following statements about the crust is NOT true?

A)Continental rocks are compositionally different than oceanic rocks.
B)It is thickest where prominent mountains exist.
C)It is the thinnest of the major subdivisions.
D)Oceanic crust is enriched in potassium, sodium, and silicon.

Question 37

is another name commonly used by scientists to denote seismic sea waves induced by earthquakes.

Question 38

The upper mantle is very close in chemical and mineralogical composition to .

Question 39

The core is probably solidified.

Question 40

The asthenosphere is located .

A)between the mantle and outer core
B)within the crust
C)in the upper mantle
D)within the outer core

Question 41

Would earthquakes of similar magnitudes in different regions of the Earth cause approximately the same levels of damage necessarily? In your explanation, consider both geologic and human- induced factors.

Question 42

Using the time- travel graph below, how long does it take a P wave to travel 2000 km?