plate tectonics

Question 1

who discovered the continental drift theory

Answer 1

alfred wegner

Question 2

what is the continental drift theory

Answer 2

all continents had originally been one big continent and began to break apart into the continents we have today

Question 3

what is the one big continent called (consisted of the continents we have today)

Answer 3

pangaea

Question 4

what are the evidences for the continental drift theory (4 evidences)

Answer 4

puzzle like fit
rock formations
matching fossils
climate evidence

Question 5

a small reptile, couldnt have crossed the ocean yet its fossils were in south america and africa, proof of matching fossils

Answer 5

mesosaurus

Question 6

a land plant found in africa, south america, australia etc. can be proof of matching fossils

Answer 6

glossopteris

Question 7

how does climate evidence supporting the continental drift theory

Answer 7

glaciers near the equator - striations and deposits found in southern Africa and South America

Question 8

what two reasons rejected the continental drift theory

Answer 8

wegner couldn’t find why the continents moved

Question 9

where do earthquakes and volcanoes occur

Answer 9

plate boundaries

Question 10

what is a plate boundary

Answer 10

2 plates are either pushing away, pulling away, or sliding against each other

Question 11

how do earthquakes occur (strain, fractures)

Answer 11

strain builds up along boundaries and when it becomes too much fractures form and earthquakes occur

Question 12

how do volcanoes form (heat, molten rock)

Answer 12

boundaries have a lot of heat flow, where molten rock moves up to the surface

Question 13

what is a magnetic field (of earth)

Answer 13

invisibles lines of force that pass through earth from one pole to another

Question 14

what does earths magnetic field do once and a while (hint: a compass would point to the south during this)

Answer 14

reversal

Question 15

what is paleomagnetism and what was it used for

Answer 15

natural magnetism in rocks, determine locations of magnetic poles in rock

Question 16

how did paleomagnetism help with evidence for seafloor spreading

Answer 16

discovery of strips of alternating polarity in rock

Question 17

what is seafloor spreading

Answer 17

tectonic plates separating from each other and making new ocean floor material

Question 18

where does seafloor spreading occur

Answer 18

mid-ocean ridges

Question 19

seafloor spreading spreads about __ cm per year, rock and sediment are youngest near the _____ oldest near the _______

Answer 19

5, ridge, trenches

Question 20

what are the layers of the earth from outer to inner (4 layers)

Answer 20

crust, mantle, outer core, inner core

Question 21

what is the lithosphere

Answer 21

rigid part, made of crust and mantle

Question 22

what is the asthenosphere

Answer 22

under lithosphere, made of upper mantle, plates move around on top of asthenosphere

Question 23

divergent boundary

Answer 23

two plates move apart

Question 24

convergent boundary

Answer 24

two plates collide into each other

Question 25

subduction zone

Answer 25

one oceanic plate is forced under another plate

Question 26

what are the three types of convergent boundaries

Answer 26

ocean-continental ocean-ocean continental-continental

Question 27

describe ocean-continental boundary and what it makes

Answer 27

less dense, plates float above and more dense ocean plates sink, forms volcanoes

Question 28

describe ocean-ocean boundary and what it makes

Answer 28

one ocean plate subducts under another plate, forms volcanic islands

Question 29

describe continental-continental boundary and what it makes

Answer 29

floats since lithosphere can't be subducted, forms mountain ranges

Question 30

transform boundary

Answer 30

2 plates slide past each other horizontally, sliding motion can cause earthquakes

Question 31

where do mountains form

Answer 31

long belts near convergent plate boundaries, continental margin boundary (between ocean and cont. crust)

Question 32

what affects rocks at convergent boundaries

Answer 32

stress

Question 33

what are the 3 types of stress and define them

Answer 33

compression- squeezed inward tension- stretched shear- pushed in opposite directions

Question 34

during plate collision stress can cause rock layers to bend into ______

Answer 34

folds

Question 35

break in lithosphere where movement has occurred

Answer 35

fault

Question 36

what are the three types of faults and define each of them

Answer 36

normal- hanging wall moves down relative to footwall reverse- handing wall move up relative to footwall strike-slip- rocks on opposite sides of fault horizontally

Question 37

what is an earthquake

Answer 37

movement in ground caused by sudden rocks moving along a fault

Question 38

focus

Answer 38

location under earth's surface where rocks begin to move or break

Question 39

epicenter

Answer 39

point on earth's surface directly above the focus

Question 40

waves that travel from inside the earth

Answer 40

body waves

Question 41

primary - travel through solids and liquids, fastest seismic waves, back-and-forth motion

Answer 41

p waves

Question 42

secondary waves, travel only through solids, fast moving not as fast as p waves, side to side movement

Answer 42

s waves

Question 43

waves that travel along earths surface, move slowly, cause most damage

Answer 43

surface waves

Question 44

cause ground to move in a side to side motion

Answer 44

love wave

Question 45

particles of material move in circular patterns

Answer 45

rayleigh waves

Question 46

what tool is used to record waves made by an earthquake

Answer 46

seismograph

Question 47

the sheet a seismograph prints out and determines strength and location is called what

Answer 47

seismogram

Question 48

measure of amount of energy released

Answer 48

magnitude

Question 49

scale used to measure strength of earthquakes

Answer 49

richter scale

Question 50

scale used to measure amount of earthquake damage

Answer 50

modified mercalli

Question 51

large earthquakes followed by small rippling ones this is called

Answer 51

aftershocks

Question 52

movement of magma on earth

Answer 52

volcanism

Question 53

vent that magma and gases come out is a

Answer 53

volcano

Question 54

areas of volcanism that dont occur along plate boundaries

Answer 54

hot spots

Question 55

solid hot material from deep in mantle rises and reaches lithosphere

Answer 55

mantle plumes

Question 56

plume spreads out and magma breaks into surface forming...

Answer 56

hot spot volcanoes