Natural Hazards - Tectonic

Question 1

What are earthquakes and volcanoes caused by?

Answer 1

The movement of tectonic plates

Question 2

Explain what the continental and oceanic crust are like

Answer 2

Continental - thick, less dense

Oceanic - thin, more dense

Question 3

Explain the Earths structure

Answer 3

Crust - mantle - outer core - inner core

Question 4

Explain what the inner core and outer core are like

Answer 4

Inner - solid ball of iron and nickel

Outer - liquid

Question 5

Explain what the mantle and crust is like

Answer 5

Mantle - semi-molten rock which moves very slowly

Crust - very thin (about 20 km), divided into different tectonic plates

Question 6

When do tectonic plates move?

Answer 6

When the mantle underneath them moves

Question 7

What are the types of plate margin?

Answer 7

Destructive
Constructive
Conservative
Collision/convergent

Question 8

What is a destructive plate margin?

Answer 8

Plates move towards each other

Oceanic and continental plates meet

The denser oceanic plate sinks

Create volcanoes, therefore crust is destroyed

Question 9

What is a constructive plate margin?

Answer 9

2 plates move away from each other

Magma rises from the mantle, which fills the gap of where the 2 plates moved apart, the magma cools which creates new crust

Question 10

What is a conservative plate margin?

Answer 10

2 plates move past each other, or are moving in the same direction but at different speeds

Crust isn’t created or destroyed

Question 11

What is a collision/convergent plate boundary?

Answer 11

2 continental plates collide

Crust isn’t created or destroyed, fold mountains are created because the plates push each other up

Question 12

How does a destructive plate margin create earthquakes?

Answer 12

If the oceanic plate gets stuck as it moves past the continental pressure builds up, then as they move past they send out vibrations which causes earthquakes

Question 13

How do constructive plate margins create earthquakes?

Answer 13

As the plates move away from each other the pressure builds up along cracks within the plates, then as they move past each other they send out vibrations which cause the earthquake

Question 14

How do conservative plate margins create earthquakes?

Answer 14

As the plates moving past each other get stuck and pressure builds up, then as they move past each other they send out vibrations and cause an earthquake

Question 15

How does an earthquake form?

Answer 15

Pressure builds up as the plates move past each other

As the plates move past they send out shock waves

The shock waves spread out from the focus

Question 16

What plates are volcanoes found at?

Answer 16

Oceanic and conservative

Question 17

How do oceanic plates cause volcanoes?

Answer 17

The plate moves down into the mantle, where it’s melted and destroyed

A pool of magma is formed

The magma rises through the cracks in the crust

The magma erupts onto the surface, forming a volcano

Question 18

How does a constructive plate cause a volcano?

Answer 18

Magma rises up through the gap created by the pages moving away from each other, forming a volcano

Question 19

Where else do volcanoes form other than destructive/constructive plate boundaries?

Answer 19

Parts of the mantle that are really hot, called hotspots

Question 20

What are the primary impacts of earthquakes?

Answer 20

Buildings and bridges collapse

People are injured or killed

Infrastructure damaged

Electricity/water/gas/telephone connections are damaged and cut off

Question 21

What are the secondary impacts of earthquakes?

Answer 21

Can trigger landslides/tsunamis which create more damage

Homeless people due to damaged buildings

People may suffer psychological problems

Shortage of food/water more death

Unemployment due to damaged buildings

Roads are blocked because of damage meaning aid can’t get through

Question 22

What makes impacts of earthquakes worse in LEDCs?

Answer 22

Poor quality housing, means they are more likely to be destroyed

Infrastructure is poorer, makes it harder for emergency devices to reach people leads to more death

Don’t have the money for protection/planning

Healthcare is worse more people die

Question 23

Why do people continue to live where earthquakes happen?

Answer 23

They’ve always lived there - don’t want to leave friends/family

Don’t want to lose jobs

They don’t think an earthquake will happen again

They’re confident they will get the support from the government if an earthquake were to happen

Question 24

What are the ways of reducing the impacts of earthquakes?

Answer 24

Prediction

Building modification

Planning

Education

Aid

Question 25

How can you Predict an earthquake?

Answer 25

Small tremors
Cracks appearing in rocks
Strange animal behaviour
Looking at data from previous earthquakes

Question 26

How can Buildings be Modified to reduce the impacts of earthquakes?

Answer 26

Using materials like reinforced concrete or special foundations that absorb the earthquakes energy

Question 27

How can you Plan to reduce the impacts of earthquakes?

Answer 27

Building future buildings in areas that aren’t earthquake-prone

Firebreaks

Emergency services

Evacuation routes

Question 28

What Education can be provided to reduce the impacts of earthquakes?

Answer 28

Tell people how to evacuate

Tell people how to make survival kits, including food, water, torch, radio, batteries ect

Question 29

How can Aid help to reduce the impacts of an earthquake?

Answer 29

Providing food, water, money or people (doctors/rescuers) ect

Question 30

What makes a way of reducing the impacts of earthquakes sustainable?

Answer 30

Effective, environmentally friendly, cost effective

Question 31

Why do people live near to volcanoes?

Answer 31

Soil around the volcano is fertile, because of the minerals found in ash & lava, which attracts farmers

Volcanoes are tourist attractions

They are also a source of geothermal energy, used to create electricity, so people live nearby to work at power stations

Question 32

What are the primary impacts of volcanoes?

Answer 32

Buildings/roads destroyed by lava and pyroclastic flows, buildings also collapse if too much ash falls on them

People/animals injured or killed by pyroclastic flows/lava/falling rocks/suffocated by CO2

Crops damaged with ash or suffocated by CO2

Water supplies contaminated with ash

Question 33

What are the secondary impacts of volcanoes?

Answer 33

Mudflows formed by volcanic material and water, this causes more destruction death and injuries

Fires caused by lava and pyroclastic flows

People suffer from psychological problems

Shortage of food and water

Roads blocked/destroyed so aid can’t get through

Unemployment through damaged buildings

Sulphur dioxide released into the atmosphere causes acid rain

Question 34

What are the ways of reducing the impacts of volcanoes?

Answer 34

Prediction 
Planning 
Building modification 
Education 
Aid

Question 35

How can you Predict an volcano to reduce the impacts?

Answer 35

Small earthquakes
Escaping gas
Changes in the shape of the volcano

Question 36

How can you Plan to reduce the impacts of a volcano?

Answer 36

Buildings built in areas that aren’t volcano-prone

Firebreaks to reduce the spread of fires

Emergency services

Evacuation routes

Question 37

How can Modifying Buildings reduce the impacts of volcanoes?

Answer 37

Buildings can’t be built to withstand lave or pyroclastic flows

Can be strengthened so they’re less likely to crash under ash

Lava can be diverted away from buildings with barriers

Question 38

How can Education reduce the impacts of volcanoes?

Answer 38

Evacuation routes can be made

Survival kits which contain food, water, batteries, torch, radio, and dust masks

Question 39

How can aid be used to reduce the impacts of volcanoes?

Answer 39

Bringing in food, water, money or people