Earth Science

Question 1

what was the super continent called before it broke up into countries

Answer 1

Pangaea

Question 2

what happened to Pangaea

Answer 2

it broke up into lots of pieces because of continental drift years ago

Question 3

list some evidence about Pangaea breaking

Answer 3

mountains on north america and west Europe are similar, coal deposits found in Antarctica ( now to cold for plants though), evidence of glaciers in Africa.

Question 4

whats under the sea that relates to this subject

Answer 4

undersea moutains

Question 5

whats interesting about the rocks in the undersea mountains

Answer 5

the are younger than the rocks from the ocean floor

Question 6

why do tectonic plates move

Answer 6

because of connection currents in the semi-fluid layer of rocks beneath the plates (the mantle)

Question 7

whats magma

Answer 7

molten rock

Question 8

what happens when magma is rising

Answer 8

pushing plates apart at spreading centres in oceans and the colder and denser magma near the surface sinks

Question 9

what keps mantle molten warm

Answer 9

decay of radioactive elements

Question 10

explain a earth crust

Answer 10

outer, mostly solid rock layer, made from granite

Question 11

What is oceanic crust made of

Answer 11

made from basalt

Question 12

explain the mantle

Answer 12

dense, upper part is brittle, lower part is molten rock

Question 13

what is the mantle rich in

Answer 13

iron, magnesium, silicon

Question 14

what’s in the outer core

Answer 14

liquid iron and nickel

Question 15

what’s in the inner core

Answer 15

solid iron and nickel because of pressure

Question 16

what is the lithosphere

Answer 16

makes up the tectonic plates, crust and mantle

Question 17

what is asthenosphere

Answer 17

makes up molten layer beneath plates, lower mantle

Question 18

what happens to the temperature the deeper you go into the earth crust

Answer 18

it becomes hotter

Question 19

where does the earth’s heat come from

Answer 19

radioactive element decay, friction between rock masses in the crust and mantle, heat left over from the planet formation

Question 20

how does the earth lose heat to outer space

Answer 20

because rock is not a good heat conductor

Question 21

what are the 3 plate boundaries

Answer 21

divergent, convergent, transform boundaries

Question 22

explain divergent boundaries

Answer 22

where the plates spread apart

Question 23

how is oceanic crust made

Answer 23

basaltic lava flows from the ridges that are made by the divergent boundaries and it makes it

Question 24

what’s a convergent boundary

Answer 24

where 2 plates collide

Question 25

name the 3 different kinds of convergent boundaries

Answer 25

continental-continental, continental-oceanic, oceanic oceanic

Question 26

explain C-C boundary

Answer 26

when the continental plates collide, neither is dense enough to be pushed down, so the land will buckle.

Question 27

explain C-O boundary

Answer 27

when one of the plates thats colliding is pushed down into the mantle because of the oceanic plate

Question 28

explain O-O boundary

Answer 28

when 2 oceanic plates collide, one plate subducts beneath the other plate

Question 29

is the O plate more dense or is the C plate more dense

Answer 29

C plate

Question 30

what is always happening to O plates?

Answer 30

always being recycled

Question 31

explain a transform boundary

Answer 31

where 2 plates slide by each other

Question 32

how does magma form

Answer 32

whenever the temperature and pressure is high enough to melt rock

Question 33

explain how a volcano works

Answer 33

melted rock rises becoming more dense than surrounding rock, then the magma moves up and if it reaches the surface it will blow

Question 34

how does a eruption happen

Answer 34

when the magma comes up, the pressure is reduced and all the dissolved gas comes up as bubbles, bubbles expand and explode basically erupting.

Question 35

what is ash

Answer 35

gritty sand particles from a volcano. sometimes can block the sky making the surrounding area cooler

Question 36

what is lava

Answer 36

simpler name for magma

Question 37

what is pyroclastic flow

Answer 37

destructive mix of superheated mix of ash, gas, debris. moves fast

Question 38

what is lahar

Answer 38

flow of mud, water, ash, and debris that happens if volcano is snow covered

Question 39

explain a composite volcano

Answer 39

a common kind of volcano that erupt normally, cone shaped

Question 40

explain a divergent boundary volcano

Answer 40

lava flows out of them at mid ocean ridge. sometimes they will rise above water to make an island

Question 41

explain a shield volcano

Answer 41

sometimes, extremely high temps are found beneath the middle of oceanic plates where there is high concentration of radioactive elements. the magma rises up and makes a ring of islands. the magma keeps going on making new islands, each one becoming bigger and bigger. the islands also each have a volcano on them. the best example of this is hawaii

Question 42

What’s is a earthquake

Answer 42

Shaking in the ground from a result of sudden energy in the earths crust

Question 43

What is the focus

Answer 43

Location where the energy is released beneath the earth

Question 44

What is the epicentre

Answer 44

Point on surface that’s above focus

Question 45

Where do earthquakes occur

Answer 45

At various depths in the earth

Question 46

What makes earthquakes cause more damage

Answer 46

Nearer to the surface means the bigger it is

Question 47

What is the cause of earthquakes

Answer 47

Rock masses on the side of a fault are pushing past each other and they bend and compress until there is so much energy stored it overecomes the friction of the rocks. It’s then released as kinetic energy called an earthquake

Question 48

What are the 3 waves called

Answer 48

Primary, secondary, and surface (other name is love) waves

Question 49

How do P waves move

Answer 49

By moving in the same direction of the wave

Question 50

Where do P waves move

Answer 50

Through solid and liquid

Question 51

Where S waves move

Answer 51

Perpendicular to the wave

Question 52

Where do S waves move

Answer 52

Only solids

Question 53

What is the motion for a love wave

Answer 53

Ground motion is a rolling action like ripples on a pond

Question 54

In what order do the waves come during a earthquake

Answer 54

P wave, S wave, last is love wave

Question 55

What is a seismometer

Answer 55

Instrument that measures ground motion resulting from earthquakes and produces a zig zag tracing on paper

Question 56

What is a richter scale

Answer 56

Standardized scale of earthquake magnitude (shaking)

Question 57

What does each point represent

Answer 57

Vibrations that are ten times greater than the point below it

Question 58

What is ground shaking

Answer 58

Result of waves set in motion by earthquake

Question 59

What kind of vibrations are a buildings weaknes

Answer 59

Side to side. They often survive up and down

Question 60

Explain liquidfication

Answer 60

Vibrations cause ground to rise turning solid ground into a liquid like material

Question 61

Which buildings are at risk during liquidfication

Answer 61

Ones on bog muds or soft fill. Ones on rock are safe

Question 62

What’s a tsunami

Answer 62

Large ocean waves made when a earthquake happened underwater

Question 63

What are the names of the 3 plates subducting underneath the North America plate

Answer 63

Juan De Fuca, Explorer, and Gorda plate. They are the reason why bc will have a big earthquake

Question 64

Rift valley

Answer 64

A rift valley is formed on a divergent plate boundary, a crustal extension or spreading apart of the surface,which is subsequently further deepened by the forces of erosion.