Tectonic plates

Question 1

What are tectonic plates

Answer 1

earth’s crust split up into multiple large slabs

Question 2

How thick are the tectonic plates

Answer 2

tens to hundreds of KM thick

Question 3

What are the tectonic plates called that make up the land

Answer 3

continental crust

Question 4

What are the tectonic plates that make up the ocean

Answer 4

oceanic crust

Question 5

Describe the continental crust

Answer 5

old, less dense and thick

Question 6

Describe the oceanic crust

Answer 6

younger (but still very old), dense and thin

Question 7

What causes earthquakes

Answer 7

the movement of the tectonic plates caused by physical processes

Question 8

Why do the plates move

Answer 8

due to the movement of the liquid magma within the earth

Question 9

What does the movement of magma cause

Answer 9

convection currents

Question 10

How do convection currents work inside the earth

Answer 10

• core heats up the magma in the mantle
• hot magma is less dense than its surroundings so rises up
• when it reaches the top it cools
• it becomes more dense and sinks back down
• it is heated up again and the cycle continues
• the plates which lie on top are pushed and pulled by the convection currents in the magma

Question 11

Tectonic plates move

Answer 11

very slowly in relation to each other and in different directions. They move next, towards and away from each other. Sometimes pushed over and under.

Question 12

Where the plates meet is called

Answer 12

a plate margin

Question 13

Name 3 of the tectonic plates

Answer 13

Eurasian plate, african plate, pacific plaite

Question 14

What is the global distribution of tectonic hazards

Answer 14

on plate margins such as along North and South America or in the Atlantic ocean between Africa and South America

Question 15

Do volcanoes always occur on plate margins

Answer 15

no the magma can break trough the middle of the plate and travels to the surface, known as a hotspot

Question 16

Constructive plate margin

Answer 16

plates move away from each other

Question 17

Destructive plate margin

Answer 17

plates move towards each other

Question 18

Conservative plate margin

Answer 18

plates move alongside each other

Question 19

What happens when two plates are pulled apart (constructive)

Answer 19

magma rises between the gap left by the separation, lava pours out onto the surface

Question 20

Where can constructive plate margin processes occur

Answer 20

continental and oceanic crust

Question 21

What is it called when new land is formed on the ocean floor

Answer 21

sea floor spreading

Question 22

When lava cools it forms rock which overtime can

Answer 22

form islands

Question 23

What happens during destructive plate margins

Answer 23

one of the plates sinks below the other into the mantle and is destroyed

Question 24

How can destructive plate margins cause earthquakes and volcanoes

Answer 24

1. denser oceanic curst is subducted below the continental crust
2. the subducting plate leaves a deep ocean trench
3. friction between the plates causes strong earthquakes 4. oceanic crust is melted and is pulled deeper into the mantle creating magma, causing pressure to build under the crust
4. magma pushes through the weaknesses in the crust creating volcano

Question 25

What happens when a destructive plate margins between 2 oceanic crusts meet

Answer 25

an ocean trench is formed

Question 26

What happens when a destructive plate margins between 2 continental crust meet

Answer 26

neither plate can subduct below the other so the crust is crumpled by the pressure creating fold mountains

Question 27

How can conservative plate margins cause earthquakes and volcanoes

Answer 27

parallel plates move in different directions this causes friction, this builds by over many years and sudden jolts are formed, this releases energy and vibrations. In oceanic crusts it displaces water causing tsunamis. no volcanoes because no magma

Question 28

Primary effects of tectonic hazards

Answer 28

killed by the hazard itself - building collapsing due to earthquake, roads and airports are damaged, electricity and water pipes are damaged

Question 29

Secondary effects of tectonic hazards

Answer 29

homelessness due to homes being destroyed, due to blocked roads aid cannot get through, businesses destroyed causing unemployment, repairs, earthquakes can trigger landslides/tsunamis

Question 30

Immediate responses to tectonic hazards

Answer 30

aid and recourses - food, water, medical care, shelters, financial donations

Question 31

Long-term responses to tectonic hazards

Answer 31

rebuilding infrastructure and homes, clearing effects of the hazard, building defence, reconnect electricity, water and gas

Question 32

Why do people live in hazardous places

Answer 32

benefits - volcanic ash fertilises soil - more crops more money, hazards are monitored and managed - better building system, infrequent events - may never happen in their lifetime, poverty - can’t afford to move away

Question 33

Hazard management - monitoring

Answer 33

detecting and recording physical changes and warning signs

Question 34

Hazard management - predicting

Answer 34

historic trends and computer based modelling to predict when a tectonic event may occur, giving time to evacuate - deaths and injuries

Question 35

Hazard management - protecting

Answer 35

increasing the resistance of a population to tectonic hazards by physically designing things that will withstands = buildings can be built with special foundations to absorb the shock of an earthquake

Question 36

Hazard management - planning

Answer 36

having system in place such as evacuation routes so that of an event does occur the population is prepared in advance, supplies can be stockpiles if needed, services can be trained to understand what to do in the scenario

Question 37

What are earthquakes measured in and what does it measure

Answer 37

moment magnitude scale, measures amount of energy released by the earthquake, magnitude 7 and above causes major damage

Question 38

What are the 3 P’s for tectonic hazards

Answer 38

prediction, protection, planning