Earth's Interior

Question 1

What is one of body waves characteristics that affect shaking

Answer 1

They reflect and/or refract through layers of rock

Question 2

What does refraction mean?

Answer 2

The wave/ light BENDS

Question 3

What type of waves do earthquakes generates?

Answer 3

ALL WAVE TYPES

Question 4

What happens when a wave is reflected or refracted?

Answer 4

Some of the energy of one type is converted to waves of the other type

Question 5

What do waves of different types have in common?

Answer 5

The velocity at which they travel DEPENDS ON THE MATERIAL (rocks) THAT THEY PASS THROUGH

P and S waves travel more rapidly through basalt than through granite
=seismic waves travel faster in a solid than a liquid

Question 6

What does the velocity of seismic waves depend on?

Answer 6

Increase with depth

Question 7

What path do seismic waves follow?

Answer 7

The paths through the interior are curved

DO NOT FOLLOW A STRAIGHT PATH

earth is layered and made of diff materials that conduct P and S waves at diff velocities
bend as they go through each layer

Question 8

What is the basic data of seismology

Answer 8

Travel times

Question 9

How many seismographs and clocks enable seismologists to measure the travel times of P, S, and surface waves precisely

Answer 9

Thousands

Question 10

What do travel times depend on?

Answer 10

Their velocities

Question 11

Which seismic waves reach a nearby seismograph first?

Answer 11

Waves traveling only in the crust

Question 12

What is the crust-Mantle boundary called

Answer 12

Moho

Question 13

Which seismic waves reach a distant seismograph first?

Answer 13

Waves traveling most of their path in the mantle

Question 14

Is the outer core solid or liquid?

Answer 14

liquid

Question 15

What do you need to know travel data?

Answer 15

Total travel time
Speed limit (speed of seismic waves in rocks inside Earth)

Question 16

How does path change?

Answer 16

The velocity changes with depth in the Earth

Question 17

What is the p-wave shadow zone?

Answer 17

Earth has a core made of a material different from that of the overlying mantle

waves are bent downward
downward bending means that the waves travel more slowly in the core than in the mantle

P-waves move much more slowly in liquids than in solids

Question 18

What is the s-wave shadow zone?

Answer 18

Other side of the core

Proved the outer core is liquid

when they hit the core, the fail to emerge from the other side

Question 19

PP waves

Answer 19

P waves that bounce off the Earth’s surface back into Earth

Question 20

SS

Answer 20

S waves that reflect back into Earth

Question 21

ScS

Answer 21

S wave that reflected at the outer core/mantle boundary back to the surface

Question 22

PcP

Answer 22

P waves that are reflected at the outer core/mantle boundary

Question 23

PKP

Answer 23

P waves that penetrate the outer core

Question 24

PKIKP

Answer 24

P waves that penetrate the inner core

Question 25

How are PP, SS, PcP, ScS, PKP, PKIKP differentiated?

Answer 25

Differentiated from one another by their amplitude and frequency

Question 26

What is geotherm

Answer 26

indicated the change in temperature as depth increases in the Earth

Question 27

What is the melting curve

Answer 27

indicates the temperature at which materials melt as depth increases in the Earth

Question 28

what is the geothermal gradient

Answer 28

the rate of change in temperature with depth e.g. 20 C/km

Question 29

How to determine the p-wave velocity

Answer 29

sqrt ((K + (4/3u))/p)

K=the bulk modulus (the modulus incompressibility) of a material
u=the shear modulus (modulus of rigidity)
p=the density

travel speeds between 1 and 14 km/sec

the slower numbers

Question 30

How to determine the s-wave velocity

Answer 30

sqrt (u/p)

u=the shear modulus (modulus of rigidity)
p=the density

Question 31

What is seismic tomography

Answer 31

uses travel times to create 3-D images of Earth’s Interior

reveals features in the mantle clearly associated with mantle convection

hot and cold inside Earth