Plate Technotes

Question 1

what are the four layers on earth?

Answer 1

crust, mantle, outer core and inner core.

Question 2

what are two types of crust?

Answer 2

oceanic and continental crust

Question 3

what is the other name for the crust?

Answer 3

lithosphere

Question 4

what are the two minerals that are present in the crust?

Answer 4

silica and aluminum

Question 5

what is the type of rock that is found in the oceanic
crust?

Answer 5

basalt

Question 6

is the oceanic or continental crust thicker?

Answer 6

continental crust will be thicker than the oceanic crust

Question 7

how does the thickness of the crust vary?

Answer 7

due to the oceanic and continental area of earth

Question 8

what is another name for the upper part of the mantle?

Answer 8

astrosphere

Question 9

what is the uppermost part of the mantle and crust called?

Answer 9

lithosphere

Question 10

what is the mantle a chief source to?

Answer 10

magma that finds its way up to the earths surface during volcanic eruptions

Question 11

what are the two types of minerals found in the mantle?

Answer 11

silicon and magnesium

Question 12

what is the center of the earth?

Answer 12

the core

Question 13

what are the two types of core?

Answer 13

the outer core and inner core

Question 14

what state is the inner core in?

Answer 14

solid

Question 15

what state is the outer core in?

Answer 15

liquid

Question 16

what is the heavy material that the core is made up by?

Answer 16

nickel and ironw

Question 17

what is another name for the core?

Answer 17

nife layer

Question 18

what did people believe about 250 years ago?

Answer 18

that the earth was only a few thousands of years old

Question 19

who was the first person to realise that this was not true?

Answer 19

James Hutton

Question 20

what was James Hutton’s assumption about earth?

Answer 20

he believed that earth was much older than 6,000 year old

Question 21

what was some of the things that James Hutton has noticed?

Answer 21

fossils of marine animals appeared sometimes a long way from the sea or in mountains.

rocks being eroded but there were still many rocks.

rocks were made from eroded sediments.

Question 22

What are some things that other scientists used to calcutue the age of earth?

Answer 22

rate of cooling

calculation of time take for the tidal friction to slow down earth to reach the 24 hour day

calculation of time take for the sun to condense to its current size and brightness

calculation of time take for oceans to reach its current salt levels based on the rate of erosion .

Question 23

what did William Thompson (Lord Klevin) believe in?

Answer 23

Earth was cooled from a red hot globe and also that earth is about 20- 40 million old and not 20 - 400 million years old which he said in his previously theory

Question 24

what did Kelvin based his estimate on?

Answer 24

the temperature of the surface rock

Question 25

why was Lord Kelvin's estimate not accurate?

Answer 25

- the liquids mantle underneath the earths crust had convention currents which was supplying additional heat that escaped the interior which warmed the surface. - radioactive decay also supplied heat.

Question 26

what did evidence from rocks used to be called?

Answer 26

qualitive

Question 27

How could people tell the relative age of rocks?

Answer 27

where they were in relations with other (deeper rocks would be more older) and the fossils found in the rock.

Question 28

what is radioactive dating?

Answer 28

a technology developed by scientists to quantify the age of most rocks

Question 29

how can scientists measure the age of rocks?

Answer 29

since most rocks contain radioactive elements and these elements decay at a fixed rate they can measure how much the rock has left to figure out the age.w

Question 30

what did scientists notice about the shape of large land masses?

Answer 30

that africa and south america fit together.

Question 31

what was scientists best guess on why large land masses fit together?

Answer 31

ocean floor were slowly rising and falling that made land bridges between continents

Question 32

what did Roberto Mantovani suggest?

Answer 32

volcanic activity and thermal expansion led to the continents drifting apart with the oceans filling in the gaps which he called the Expanding Earth Theory

Question 33

what was the theory that Alfred Wegner had propsed?

Answer 33

Continental Drift

Question 34

What was Pangea?

Answer 34

evidence of matching rocks, plant and animal fossils on different continents were once joined in one big continent

Question 35

what are the two continents that Pangea broke up into

Answer 35

Laurasia (north) and Gondwanaland (south)

Question 36

what did Wegner suggested on why continents moved?

Answer 36

centrifugal force of the earth's rotation

Question 37

what was paleomagnetism?

Answer 37

producing data showing that India has previously been in the southern hemisphere

Question 38

what was discorved in 1960?

Answer 38

seaflorr spreading

Question 39

What the realization made in 1960?

Answer 39

that earth crust is made up of large plates floating on top viscous molten rock

Question 40

what was Alfred Wegners theory changed to?

Answer 40

Plate Tectonis Theory

Question 41

what was the Plate Tectonis Theory?

Answer 41

it indicated that contients are not drifting aimlessly but are driven by convection currents in the mantle.

Question 42

which crust is beneath land?

Answer 42

continental crust

Question 43

which crust is beneath oceans?

Answer 43

oceniac crust

Question 44

what is the crust made up from?

Answer 44

large plate

Question 45

which crust is more dense and thinner?

Answer 45

oceaniac crust

Question 46

how to plate move?

Answer 46

the intense heat in the earth's core causes the molten rocks in the mantle layer to move in convection currents

Question 47

what do warm materials do?

Answer 47

rises and then sinks down again and then it is warmed and the process repeates itself

Question 48

what do convenction currents do to the plates?

Answer 48

drag along the plates

Question 49

what are the three basis types of movement that plate have when the edges meet one another?

Answer 49

divergent, convergent and transform

Question 50

what is divergent plate boundary?

Answer 50

when plates move apart from each other

Question 51

what is transform plate boundary?

Answer 51

pates slide past each other

Question 52

what is convergent plate boundary?

Answer 52

when plates push against each other

Question 53

what do convergent boundaries form?

Answer 53

mountain ranges and volcanoes

Question 54

what is being formed in divergent boudaires?

Answer 54

a new crust

Question 55

what is being formed in transform boundaries?

Answer 55

earthquake acitivies

Question 56

what is subduction?

Answer 56

the sideways or downwards movement of the edges of the plates in the crust into the mantle beneath another plate

Question 57

what is the motion of a transform plate boundary?

Answer 57

horizontal

Question 58

what do transform plate boundaries form?

Answer 58

fracture

Question 59

what are the three types of faults?

Answer 59

normal, reverse and transcurrent