Chapter 12 Slides Flashcards Preview

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Flashcards in Chapter 12 Slides Deck (26):
1

Three major layers

crust, mantle, core

2

Gravity and Layered Planets

dense iron sinks to the center

3

mineral phase change

lower mantle rocks undergo this as the minerals are compressed under higher pressures

4

P waves

compressional seismic
Fastest

5

S waves

shear seismic
cannot travel through liquid

6

Seismic Waves

P and S waves
travel fastest in stiff (rigid) rocks
velocities vary based on composition of the rocks
interactions between seismic waves and Earth;s layers
reflect and refract as they pass through the different layers of Earth

7

Crust

composed of basalt ad gabbro (ocean)
continental crust thicker than ocean

8

Moho

boundary between the crust and the mantle
P waves increase abruptly increase at the Moho and refract as they cross

9

Mantle

over 82 percent of Earth is the mantle
layer between the crust and the core
solid rocky layer

10

Upper Mantle

made of peridotite, iron, magnesium, rich rock
lithospheric mantle is the uppermost art of the mantle and extends down to 200 kilometers
asthenosphere weak layer beneath the lithospheric mantle
lowest portion of the upper mantle is the transition zone

11

lower mantle

extends from the transition zone to the liquid core
largest layer
56% percent of Earth's volume

12

D" layer of the mantle

boundary between the rocky lower mantle and the liquid outer core
Cool regions thought to be the remnants of subducted lithospheric plates
Hot regions through to be start of deep mantle plumes

13

outer core

liquid
absence of S waves

14

core

accounts for 1/6 of Earth's volumes

15

inner core

solid, dense sphere
growing as earth cools
rotates faster than the crust and mantle

16

Conduction and Convection

occur within Earth's interior

17

Radiation

transports heat away from Earth's surface to space

18

convection

transfer of heat where hot materials replace cold material
outer core

19

viscosity

material;s resistance to flow

20

conduction

transfer of heat through a material flow of electrons
not efficient
inner core

21

geothermal gradient

profile of earth's temperature at each depth

22

seismic tomography

involves collecting data at many different seismic station

23

geodynamo

magnetic field caused by spiraling columns of rising fluid in the outer core

24

magnetic field measured

by declination and inclination

25

declination measures

direction of magnetic north pole with respect to the geographic north pole

26

inclination

downward tilt of the magnetic lines