Earthquakes - Final Review

Question 1

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

Answer 1

aftershocks

Question 2

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

Answer 2

focus

Question 3

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

Answer 3

epicenter

Question 4

Which one of the following statements is correct?

• P waves travel through solids; S waves do not.
• P and S waves travel through liquids, but P waves do not travel through solids.”
• S waves travel through solids and P waves travel through liquids.
• P and S waves travel through liquids, but S waves do not travel through solids.”

Answer 4

S waves travel through solids and P waves travel through liquids

Question 5

______ have the highest velocities.

Answer 5

primary waves

Question 6

On a typical seismogram, ________ will show the highest amplitudes.

Answer 6

surface waves

Question 7

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

Answer 7

surface waves

Question 8

P waves ________.

Answer 8

are faster than S waves and surface waves

Question 9

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

Answer 9

arrival times of P and S waves

Question 10

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

Answer 10

design of structures
intensity and duration of the vibrations
nature of the surface material

Question 11

Most of our knowledge about Earth’s interior comes from ________.

Answer 11

seismic waves

Question 12

The lithosphere is defined as ________.

Answer 12

a rigid layer of crustal and mantle material

Question 13

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

Answer 13

basalt

Question 14

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

Answer 14

granite

Question 15

The asthenosphere is located ________.

Answer 15

in the upper mantle

Question 16

The point of origin of an earthquake is referred to as the _________.

Answer 16

hypocenter

Question 17

Which seismic waves arrive first at a seismograph station?

Answer 17

P waves

Question 18

Most large earthquakes occur__________.

Answer 18

at subduction zones

Question 19

True or False?
Earthquakes result from the sudden release of elastic strain energy previously stored in rocks surrounding a zone of fault movement.

Answer 19

true

Question 20

True or False?

S waves can travel through solid and liquid media.

Answer 20

false

Question 21

The time between the first P-wave and S-wave arrivals is a measure of the distance from a receiving station to the epicenter of the earthquake

Answer 21

true

Question 22

True or False?

The Mercalli earthquake magnitude scale is based on the total amount of energy released by the earthquake.

Answer 22

false

Question 23

True or False?

Tsunamis are caused by sudden displacement of large volumes of seawater.

Answer 23

true

Question 24

True or False?
“Unconsolidated, water-saturated soils or sediments provide good foundation materials for buildings and other structures.”

Answer 24

false

Question 25

True or False?

Continental crust is generally thicker than oceanic crust.

Answer 25

true

Question 26

True or False?

“The crust, mantle, and outer core are solid.”

Answer 26

false

Question 27

True or False?

The mantle is composed mainly of metallic iron with small amounts of magnesium silicate minerals.

Answer 27

false

Question 28

True or False?

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

Answer 28

false

Question 29

True or False?

The outer core is probably solidified.

Answer 29

false

Question 30

True or False?

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

Answer 30

true

Question 31

Three types of faults

Answer 31

Normal - divergent plate boundaries
Reverse - convergent plate boundaries
Strike-slip - transform boundaries

Question 32

P waves

Answer 32

Come first (primary)
Compressional
Travel through everything
Travel faster than S waves

Question 33

S waves

Answer 33

Come second (secondary)
Oscillating
Travel only through solids
Slower than P waves
Greater amplitude than P waves

Question 34

Intensity vs Magnitude

Answer 34

Intensity - degree of earth shaking in different areas

Magnitude - energy released at the source