tectonics

Question 1

volcano primary hazards

Answer 1

-gas
- ash
- lava
- volcanic bombs
- earthquakes

Question 2

volcano secondary hazards

Answer 2

• hunger : crops are destroyed therefore nothing to eat
• homelessness
• disease
• flooding
• deaths
• unemployment

Question 3

impacts of earthquakes happening during the day

Answer 3

• more people at work or commuting : families separated
  BUT : can see thats happening

Question 4

impacts of earthquakes happening at night

Answer 4

• its dark : you cant see whats going on
• therefore difficult to access damage and find the route to safety : cant find emergency kit

Question 5

impacts of earthquakes happening during summer

Answer 5

• warmer : shelter is in sun
• warmer temps higher risk of disease : decomposing bodies
• can get dehydrated

Question 6

impacts of earthquakes happening during the winter

Answer 6

• colder temps : need warmth, warm food, blankets
• much lower risk of diseases
• less risk of dehydration
• but more risk of getting killed from the cold

Question 7

what to have in your emergency earthquake kit

Answer 7

• water : 4 litres per person
• food - nonperishable
• flashlight
• lanterns
• AM/FM radios : battery operated
• batteries
• dusk masks : one for each family member
• paper money : electricity will be down
• toiletries
  first aid kit
• clothes and blankets

Question 8

active volcano

Answer 8

eruption can be anytime and often

Question 9

dormant

Answer 9

has been a while since it has erupted but could at any time

Question 10

ectinct

Answer 10

hasn’t erupted in a very long time therefore probably wont ever

Question 11

volcano structure : main vent

Answer 11

the weak point in the earths crust where hot magma has been to rise from the magma chamber and reach the surface

Question 12

volcano structure : secondary vent

Answer 12

produce secondary cones on the flank of the volcano

Question 13

volcano structure : crater

Answer 13

a bowl or funnel shaped depression that usually lies directly above the vent from which volcanic material is ejected

Question 14

volcano structure : magma chamber

Answer 14

The location beneath the vent of a volcano where molten rock (magma) is stored prior to eruption.

Question 15

volcano structure : layers of ash

Answer 15

alternating layers (strata) of lava, ash, cinders, blocks, and bombs

Question 16

volcano structure : ash cloud

Answer 16

A cloud formed from tiny ash particles and gases blasted from the volcano.

Question 17

volcano structure : volcanic bomb

Answer 17

a mass of partially molten rock (tephra) larger than 64 mm (2.5 inches) in diameter, formed when a volcano ejects viscous fragments of lava during an eruption

Question 18

volcano structure : lava flow

Answer 18

streams of molten rock that pour or ooze from an erupting vent

Question 19

volcano structure : pyroclastic flow

Answer 19

a hot (typically >800 °C, or >1,500 °F ), chaotic mixture of rock fragments, gas, and ash that travels rapidly (tens of meters per second) away from a volcanic vent or collapsing flow frontend

Question 20

layers of the earth

Answer 20

1: inner core, 2: outer core, 3: mantle , 4: crust

Question 21

what are conventional currents

Answer 21

plates move because of convectional currents, the core heats up the magma, making it rise, cool and sink. the heated magma rises through the mantle

Question 22

how do the convectional currents work

Answer 22

1: the outer core is very hot therefore making it rise
2: but since the mantle is less hot , when the magma reaches the top of the mantle it cools down , sinking back down
3: the magma intrution into an oceanic ridge pushes the plates away
4: the magma falls down but gets reheated and the cycle repeats

Question 23

what are destructive plate boundaries

Answer 23

the plates move towards each other

Question 24

what are constructive plate boundaries

Answer 24

the plates move away from each other

Question 25

what are conservative plate boundaries

Answer 25

plates slide past each other

Question 26

what are composite volcanoes

Answer 26

1: infrequent but explosive eruption 2: steep slopes + narrow base 3: lava cools close to the vent 4: layers of thick ash + lava 5: secondary cones

Question 27

what are shield volcanoes

Answer 27

1: frequent but non-violent eruptions 2: low rounded peak 3: lava is runny so cools far from vent 4: wide base + gentle slopes

Question 28

how do destructive plates create volcanic eruptions

Answer 28

1) is where the oceanic and continental crust are moving together 2) the dense oceanic crust sinks ( subduction ) under the lighter continental crust 3) the oceanic is melted and deformed under the friction, pressure and heate created by the subduction 4) the molten rock might rise through the crust as hot magma leading to violent volcanic eruption if released, the friction and pressure created creates powerful earthquakes

Question 29

how do constructive plates create volcanic eruptions

Answer 29

1) this is where the plates move away, this normally happens under oceans 2) convection currents pull away from each other, as they do, some creaks and fractures from between plates and there is therefore no solid connection 3) magma may force itself up through the cracks to fill the void, if it makes it to the surface it will for a volcano 4) as a result of this , new land is created

Question 30

how do convectional plates create earthquakes

Answer 30

1) this is where two plates slide past eachother side by side, they normally move in a horizontal direction at different angles or speeds 2) due to the different speeds and rough sides, they tend to get stuck or locked together, creating a building of pressure 3) as one plate suddenly slips past the other, this pressure is released and will lead to an earthquake 4) no crust is made or destroyed during this

Question 31

the formation of a composite volcano

Answer 31

1) at destructive boundaries the oceanic crust subducts underneath the continental 2) after 70km of subduction the rock starts to melt and magma rises to the surface 3) through this long 70km the magma has a lot of contact with the surrounding rock and absorbs silica from them 4) as the magma rises it has to pass through 70km of continental curst 5) once the magma arrives at the surface cools and dull of silica, this means magma cannot escape and so pressure builds up into an explosive eruption 6) lava and ask is thrown up and falls close to the crater creating a tall, steep sided volcano

Question 32

the formation of a shield volcano

Answer 32

1) at constructive boundaries the ocean crust is pulled apart by convection currents 2) when this happens the mantle below depressurises which allows magma to rise towards the surface 3)the magma only needs to pass 10km of basaltic crust 4) the thin curst and low silica basalt means the magma does not absorb much silica 5) after the magma arrives at the surface, it is still very hot and low in silica so a runny lava is produced 6) lava easily escapes, no explosion means little ash. lava flows quickly and cools far from the crater creating low and wide volcano

Question 33

definition of an earthquake

Answer 33

the shaking of the ground caused by plate movement