chapter 9, test 2, earhtquakes

Question 1

earthquakes

Answer 1

a vibration of earth produced by rapid release of energy

Question 2

focus (hypocenter)

Answer 2

the place within the earth where earthquake waves orginate

energy released radiates in all directions from its source

Question 3

epicenter

Answer 3

point at the surface directly above the focus

found by using the difference in velocities between the S and P waves

Question 4

seismic waves

Answer 4

energy is in form of waves (like a droplet of water in a pond)
move faster in consolidated bedrock
move slower through unconsolidated sediment
move slowest through unconsolidated materials with water

Question 5

elastic rebound

Answer 5

as a rock deforms, it bends, storing elastic energy. when strained beyond its breaking point the rock cracks and releases the stored up energy as seismic waves

Question 6

aftershocks

Answer 6

adjustments that follow a major earthquake often generate smaller earthquakes

Question 7

foreshocks

Answer 7

small earthquakes that often precede a major earthquake by days or in some cases several years

Question 8

fault creep

Answer 8

slow gradual displacement

Question 9

seismology

Answer 9

study of earthquake waves.

Question 10

surface waves

Answer 10

travel along the outer part (surface) of the earth.
cause greatest destruction
waves exhibit greatest amplitude adn slowest velocity

Question 11

body waves

Answer 11

travel through earths interior
primary (P) waves
secondary (S) waves

Question 12

Primary (P) waves

Answer 12

travel through solids, liquids, and gases
generally P waves travel faster than S waves in solid materials
push/pull motion changing the volume of the intervening material

Question 13

Secondary (S) waves

Answer 13

travel only through solids (not liquids)
slower velocity than P waves
slightly greater amplitude than P waves.
shaking motion at right angles to their direction of travel

Question 14

Major Earthquake zones

Answer 14

pacific belt, Himalayas, and the oceanic ridge system

Question 15

Intensity

Answer 15

a measure of the degree of earthquakes shaking at a given local based on the amount of damage

Question 16

magnitude

Answer 16

estimates the amount of energy released at the source of the earthquake

Question 17

modified mercalli intensity scale

Answer 17

developed in 1902 using California buildings as its standard

Question 18

Richter Scale

Answer 18

magnitude is determined by measuring the maximum amount of ground shaking due to S waves

Question 19

liquification

Answer 19

unconsolidated materials saturated with water turn into mobile fluids

Question 20

tsunamis

Answer 20

result from vertical displacement along a fault located on the ocean floor or a large undersea landslide triggered by an earthquake.
greatest risk at subduction zones