Solid Earth

Front 1

two types of body waves

Back 1

p and s waves

Front 2

p waves

Back 2

pressure waves that move in one dimension by compressions

Front 3

s waves

Back 3

shear waves that move transverse like a slinky

Front 4

two types of surface waves

Back 4

raleigh and love waves

Front 5

what does a seismograph measure

Back 5

measures motion from the ground.

record vertical and horizontal motion and the period between waves

Front 6

most stable isotope of carbon

Back 6

C12

Front 7

alpha decay

Back 7

a helium atom is release (2 p 2 n)

Front 8

beta decay

Back 8

gaining or losing and electron or positron

Front 9

why do ray paths change in the core of the earth/mantle etc

Back 9

because the changes in density change the velocity that the wave is traveling. See Snell's law

Front 10

snell's law

Back 10

sini1/v1 = sinf1/v2

i1 is the angle from the vertical before the medium change

f1 is the angle from the vertical after the medium change

Front 11

what is a core shadow zone?

Back 11

an area where a p or s wave was unable to fully reach the other side of the planet due to changes in angle or inpenetrable material

Front 12

s waves cannot penetrate what?

Back 12

the core (inner and outer)

Front 13

4 major layers of the earth

Back 13

crust
mantle
outer core
inner core

Front 14

what are the depths for the layers of the earth

Back 14

lithosphere - 100 km
athenosphere - 700 km
mesosphere - 2885 km
outer core - 5155 km
inner core (center) - 6371 km

Front 15

what is the metallic composition of the core

Back 15

iron and nickle

Front 16

describe the inner core

Back 16

there is extreme pressure so it is solid

Front 17

describe the outer core

Back 17

molten bc of some less pressure
movees in km/yr
source of earth's magnetic field

Front 18

describe the composition of the mantle

Back 18

makes up most of the earth's volume

mostly composed of silicate materials

mostly solid

Front 19

moho

Back 19

defines the chemical boundary in crust

Front 20

compare continental and oceanic crust

Back 20

oceanic crust is heavier and is younger than continental, made of basalts

continental crust is mostly made of granite and is older. it is thicker but less dense

Front 21

lithosphere

Back 21

the area of the mantle that is fused with the crust

Front 22

athenosphere

Back 22

middle part of the mantle that has some movement

Front 23

mesosphere

Back 23

the rigid lower part of the mantle

Front 24

how does velocity behave in the mantle

Back 24

it increases with depth

Front 25

p wave shadow zone

Back 25

105 to 142

Front 26

s wave shadow zone

Back 26

an angles larger than 105 degrees

Front 27

define isotope

Back 27

varients of a chemical element in the number of neutrons but with the same number of protons

Front 28

radionucleides

Back 28

unstable isotopes that undergo decay

Front 29

what happens in beta decay (-)

Back 29

the atomic number goes up

Front 30

what happens in beta decay (+)

Back 30

atomic number goes down

Front 31

equation for radiometric dating

Back 31

N(t) = No e^(-gamma*t)

Front 32

how do you radiometrically date if you do not know initial concentrations?

Back 32

figure out ratios of daughter to parent chemical constituents

Front 33

half life

Back 33

the time it takes for half of the number of isotopes to decay

Front 34

branched decay

Back 34

a parent ion can go multiple avenues of decay

Front 35

why use K/Ar dating?

Back 35

K is common in land rocks

Front 36

what are assumptions of K/Ar dating

Back 36

closed system
atmosphere was constant in composition
sample was homogeneous
decay constants are known