Internal Structure of Earth

Question 1

a type of waves that can be classified as either a body

wave or a surface wave

Answer 1

seismic waves

Question 2

define primary wave or P-wave

Answer 2

a longitudinal (compressional)
wave

Question 3

define secondary or s-wave

Answer 3

a transverse (shear) wave

Question 4

TRUE/FALSE:
P-waves are the ‘slowest’ and they move through surface rocks and
sub-surface solid and liquid materials

Answer 4

FALSE; P-waves are the fastest

Question 5

TRUE/FALSE:

S-waves are slower and they do not travel through liquids as P-waves do

Answer 5

TRUE

Question 6

Why are S-waves slow and why can’t they travel through liquids?

Answer 6

liquids do not have the cohesion needed to transmit a shear, or side-to-side, motion

Question 7

define surface wave

Answer 7

up-anddown (crest and trough) and side-to-side waves that travel across the surface

Question 8

TRUE/FALSE:
surface waves
are the slowest among all the waves

Answer 8

TRUE

Question 9

What are the two types of surface waves?

Answer 9

Love waves and Rayleigh waves

Question 10

Who discovered Love waves?

Answer 10

Augustus Love

Question 11

Who discovered Rayleigh waves?

Answer 11

Lord Rayleigh

Question 12

TRUE/FALSE:

Love waves are ‘vertical’ surface waves, moving from side to side.

Answer 12

FALSE; Love waves are HORIZONTAL surface waves

Question 13

Love waves: horizontal surface waves; Rayleigh waves: __________

Answer 13

up and down

Question 14

TRUE/FALSE:

seismic waves travel most rapidly in rigid materials

Answer 14

TRUE

Question 15

How come seismic waves can travel faster in deeper areas?

Answer 15

deeper areas experience much higher

pressure, causing the rocks there to become more compact

Question 16

define discontinuity

Answer 16

the boundary between the two unlike materials

Question 17

Enumerate the Earth’s three zones

Answer 17

crust, mantle, and

core

Question 18

Earth’s outer layer and is very thin

Answer 18

crust

Question 19

Oceanic crust is generally made of a denser rock called ________

Answer 19

basalt

Question 20

Continental crust is a less

dense, _________ rock.

Answer 20

granite-type

Question 21

Between the crust and the layer below it, (mantle) is the boundary known
as the __________

Answer 21

Mohorovičić discontinuity

Question 22

Who discovered the Mohorovičić discontinuity and when was it discovered?

Answer 22

Andrija Mohorovičić in 1909

Question 23

A layer of the Earth that’s soft and a relatively weak layer located in the upper
mantle

Answer 23

asthenosphere

Question 24

At the uppermost part of the asthenosphere, _______________ occurs

Answer 24

partial melting

Question 25

the partial melting of the asthenosphere is called _______________

Answer 25

low-velocity zone

Question 26

an iron rich sphere at the center part of Earth

Answer 26

core

Question 27

part of the mantle found below the lithosphere; a “weak sphere”

Answer 27

asthenosphere

Question 28

the very thin outermost layer of Earth

Answer 28

crust

Question 29

boundary between two unlike materials in the interior of Earth as determined by the behavior of seismic waves

Answer 29

discontinuity

Question 30

ocation on Earth’s surface that lies directly above the focus of an earthquake

Answer 30

epicenter

Question 31

boundary between the mantle and the core

Answer 31

Gutenberg discontinuity

Question 32

rigid outer layer of Earth, including the crust and upper mantle

Answer 32

lithosphere

Question 33

part of the mantle characterized by a | decrease in the velocity of seismic waves

Answer 33

low-velocity zone

Question 34

thick layer of Earth located below the crust

Answer 34

mantle

Question 35

also called Moho; the boundary between the crust and the mantle characterized by an increase in seismic velocity

Answer 35

Mohorovičić discontinuity

Question 36

layer beneath the mantle which has the | properties of a liquid

Answer 36

outer core

Question 37

a wave that compresses and expands the material through which it moves; a longitudal wave; fastest earthquake wave

Answer 37

P-wave

Question 38

a wave that vibrates the particles of its medium up-and-dowm and sideto-side; a transverse wave; slower than a P-wave that travels only in solids

Answer 38

S-wave

Question 39

an instrument that records earthquake | waves

Answer 39

Seismograph

Question 40

study of earthquakes and seismic waves

Answer 40

seismology

Question 41

zone between about 103° and 142° distance from the epicenter of an earthquake which direct waves do not penetrate because of the refraction by Earth’s core

Answer 41

shadow zone

Question 42

TRUE/FALSE: Seismic waves are reflected and refracted (or bent) at boundaries of unlike materials

Answer 42

TRUE