Component 1 Topic 1

Question 1

What are the three types of cells?

Answer 1

Hadley
Ferrel
Polar

Question 2

Where on the earth is the most solar radiation received?

Answer 2

Most solar radiation is received at the equator. This is because the sun’s rays have to travel a shorter distance and through a less dense atmosphere to get there. The atmosphere is thinner because the heat from the ground warms it.

Question 3

What is the difference between high and low pressure?

Answer 3

High pressure is caused by cold air as as the cold air cools, it falls to the earth’s surface and puts lots of pressure on it. Low pressure is caused by hot air as the warm air rises and so puts less pressure on the earth’s surface

Question 4

How do global atmospheric cells transfer heat energy around the world?

Answer 4

• Most heat is at the equator
• The cool air from the equator moves to 30° north and south
• At 30°, the cool air sinks creating a high pressure belt with low rainfall and cloudless skies
• The cool air is either moved back to the equator by trade winds or towards the poles by westerlies
• At 60°, the warm surface winds meet cold air from the poles. The warm air rises and creates low pressure and frontal rain
• This air either goes back to the equator or the poles
• At the poles the cold air sinks creating high pressure

Question 5

How is heat transferred by ocean currents?

Answer 5

• Ocean currents transfer heat from warmer to cooler regions
• Surface currents are caused by winds and transfer heat away from the equator e.g. the gulf stream
• Deep ocean currents are driven by differences in water density
• When water freezes at the poles the water around it becomes denser due to the increase in its salt levels
• When it becomes denser it sinks, causing warmer water to flow at the surface
• The warmer water cools and sinks, continuing the cycle
• This cycle moves water in a big loop around the world, known as thermohaline circulation

Question 6

What are the 4 natural causes of climate change?

Answer 6

• Orbital changes
• Volcanic activity
• Solar output variation
• Asteroid collisions

Question 7

How do orbital changes cause climate change?

Answer 7

• Eccentricity:
  
  • The orbit of the earth changes from a near perfect circle to an oval shape roughly every 100,000 years
  • If the orbit is more spherical then the earth is warmer, if it is more oval shaped then the earth is colder
• Tilt
  
  • Over a period of 40,000 years, the earth’s axis tilts from between 23° to 24.5°.
  • If it is tilted more away from the sun, then the seasons are more pronounced, whereas if it is tilted less away from the sun, the the seasons are less pronounced
• Wobble
  
  • Over a period of 24,000 years, the earth’s rotation on its axis changes and the direction the axis faces changes, giving us smaller diferorrences between the seasons

Question 8

How does volcanic activity cause climate change?

Answer 8

• Major volcanic eruptions eject large quantities of ash and other materials into the atmosphere
• Some of these particles reflect the sun’s rays back into space, causing the earth to cool

Question 9

How does solar output variation cause climate change?

Answer 9

• The sun’s output of energy isn’t constant and changes in short cycles of about 11 years
• Periods when the output is reduced will cause the earth to be cooler and vice versa

Question 10

How do asteroid collisions cause climate change?

Answer 10

• Asteroids hitting the earth’s surface can through large amounts of dust into the atmosphere
• This dust prevents the sun’s rays from hitting the earth and so causes global temperatures to fall

Question 11

How can tree rings be used as evidence of climate change?

Answer 11

• If the tree rings are thicker one year it means that year was hotter
• If the rings are thinner, then it means that the year was colder
• If there is a scar in the tree it means that there was a forest fire that year

Question 12

How can ice cores be used as evidence of climate change?

Answer 12

• Ice sheets are made up of layer of ice, one formed every year
• Scientists can analyse the gases trapped in each layer of the ice cores to see what the temperature was like that year

Question 13

How can historical sources be used as evidence for climate change?

Answer 13

• Since the 1850s, thermometers have been used and give a reliable temperature of each year
• Other sources such as diaries and paintings can give a less reliable idea of what the climate was like going hundreds of years back

Question 14

How are humans contributing to the greenhouse effect and global warming?

Answer 14

• Farming: Increases the amount of methane and CO2 in the atmosphere
• Industry: Increases the amount of methane and CO2 in the atmosphere
• Energy: Increases the amount of CO2 in the atmosphere
• Transport: Increases the amount of nitrous oxides in the atmosphere

Question 15

What are the main consequences of climate change?

Answer 15

• Rise in sea levels due to thermal expansion and the melting of Arctic Ice
• Increase in the amount of heat related deaths
• Loss of land due to costal flooding as well as areas becoming too hot and dry to inhabit
• Increase in the frequency and severity of extreme weather events
• Decrease in crop yields in some countries due to the hot temperature leading to starvation and malnourishment

Question 16

What are the factors required for tropical cyclones to form?

Answer 16

• The sea temperature must be above 26.5ºC
• They form between 5º and 30º north and south of the equator
• There must be converging winds over the water

Question 17

What is the structure of a tropical cyclone?

Answer 17

• There is clear sky and now wind in the eye
• The wind rotates outwards at the top
• Warm moist air rises and pulls towards the centre
• Cloud tops can reach 12-15km high
• A dense canopy of cirrus clouds form at the top
• Winds increase in strength at the eye wall
• Cumulonimbus clouds form
• They form in the late summer in the northern hemisphere and between Jan and March in the Southern hemisphere

Question 18

What are the physical hazards of tropical cyclones?

Answer 18

• High Winds: some winds can reach 250km/h
• Intense rainfall: storms take up trillions of litres of water which all falls as rain
• Storm surges
• Landslides: caused by heavy rain making hillsides unstable

Question 19

What are some of the impacts of tropical cyclones on people?

Answer 19

• Drownings
• Homelessness
• Risk of being hit by debris
• Electricity supplies being cut off
• Contaminated water supplies
• Easy for diseases to spread
• Shortage of food
• Increase in unemployment
• Difficulty for emergency aid to reach the damaged zones

Question 20

What are some of the impacts of tropical cyclones on the environment?

Answer 20

• Damage or destruction of wooded habitats
• Damage of costal habitats through erosion
• Pollution of freshwater environments with sea water
• Deposition if sediment in rivers and lakes kills fish and and other wildlife
• Harmful chemicals leaking into the environment

Question 21

Why are some countries more vulnerable than others to tropical cyclones?

Answer 21

• Physical vulnerability: e.g relief of an area or location within the path of cyclones
• Economic vulnerability: e.g. damage to agriculture affects poor countries, poor countries don’t often have building insurance
• Social vulnerability: poorer countries are more at risk because: buildings are more easily damaged, healthcare is of poorer quality, harder to rescue people because of poorer infrastructure

Question 22

How can countries prepare for tropical cyclones?

Answer 22

Forecasting:

• When and where tropical cyclones will hit can be predicted
• These predictions allow people to evacuate and protect their property

Evacuation:

• Warning strategies allow people to leave their homes in time
• These evacuations reduce the numbers of those killed and injured by the tropical cyclone

Defences:

• Defences like sea walls can be built to prevent damage from storm surges. Buildings can also be built e.g. on stilts to protect them from floodwater
• These defences reduce the number of buildings destroyed and damaged and so reduces the number of those killed, injured, made homeless and made unemployed

Question 23

How can countries respond to tropical cyclones?

Answer 23

Rescue:
-Rescue workers search for anyone trapped in rubble or buildings. The sooner they are found the more likely they are to survive. The better orchestrated a rescue, the more survivors there will be

Rebuild:
-Quick rebuilding of roads, electricity and other infrastructure allows the emergency services to get to people quicker and so reduces the number of deaths

Question 24

What are the different layers of the earth and what are their characteristics?

Answer 24

The core:

• A ball of solid(inner) and liquid(outer) iron and nickel
• Very dense in the centre and less dense further out
• Temperature ranges from 4400-6000ºC

The mantle:

• Made up of silicone based rocks
• Quite rigid near the centre
• Above this layer is the asthenosphere which is semi-molten
• Above this the mantle is rigid
• Temperature ranges from 1000-3700ºC

The crust:

• Made up of silicone based rocks
• Continental crust: thicker and less dense
• Oceanic crust: thinner and more dense

Question 25

How do tectonic plates move by convection currents?

Answer 25

• The tectonic plates float on the mantel
• Radioactive decay of some parts of the mantle generates lots of heat
• Lower parts of the asthenosphere heat up, become less dense and slowly rise
• As these parts rise to the top they cool and sink
• These movements (convection currents) create drag at the base of the plates and cause them to move

Question 26

What are the three types of plate boundaries?

Answer 26

• Convergent
• Divergent
• Conservative

Question 27

What are convergent boundaries

Answer 27

• When two plates are moving towards each other
• When an oceanic plate meets a continental plate, the oceanic plate is forced into the mantel and destroyed, creating volcanoes and ocean trenches
• When two continental plates meet, they collide and the ground is folded creating mountain ranges

Question 28

What are divergent boundaries?

Answer 28

• Where two plates move away from each other

- Magma rises up from the mantle through the gap and cools, creating a new crust

Question 29

What are conservative boundaries?

Answer 29

• Where two plates either move past each other or are moving in the same direction but at different speeds
• Crust is neither created or destroyed

Question 30

What are the two types of volcanoes?

Answer 30

• Composite volcanoes

- Shield volcanoes

Question 31

What are composite volcanoes?

Answer 31

• They form at convergent plate boundaries
• They have explosive eruptions containing lots of ash and gases
• They erupt andesitic lava which has a high silica content. This makes it thick and sticky meaning it can’t flow far and so it forms a steep sided cone

Question 32

What are shield volcanoes?

Answer 32

• They occur at hotspots or divergent plate boundaries
• They are not very explosive and erupt only lava
• They erupt basaltic lava which has a low silica content and is runny. It flows quickly and spreads over a wide area, forming a low, gentle sided volcano

Question 33

How can earthquakes occur at all types of plate boundaries?

Answer 33

Convergent:
-Tension builds up when one plate gets stuck as it moves past the other into the mantle

Divergent:
-Tension builds up along cracks within the plates as they move away from each other

Conservative:
-Tension builds up when plates that are grinding past each other get stuck

Question 34

Which type of earthquake, shallow-focus or deep-focus, cause more damage to the surface?

Answer 34

-Shallow focus do, as the shock waves have to travel through less rock than deep-focus and so have more energy, allowing them to do more damage

Question 35

How do earthquakes cause tsunamis?

Answer 35

• The earthquakes cause the seabed to move which displaces large amounts of water
• Shallow focus earthquakes make larger tsunamis
• The waves travel very fast and hit the shore without warning causing a high death toll

Question 36

How can earthquakes be predicted?

Answer 36

-They can’t be reliably predicted, but they certain signs can be monitored to indicate when an earthquake is likely
These are:
-Lasers can detect the movement of tectonic plates before an earthquake
-Vibrations can be monitored using seismometers. If vibrations increase it means that there will be an earthquake
-Gases can be measured to know when an earthquake will happen
-Rocks will crack and expand right before an earthquake

Question 37

How can volcanic eruptions be predicted?

Answer 37

• Tiny earthquakes and changes in the shape of a volcano mean that an eruption is likely
• Temperatures can be monitored, with an increase meaning that an eruption is imminent
• Volcanoes emit lots of sulphurous gases before an earthquake

Question 38

How can long-term planning prepare a country for tectonic hazards?

Answer 38

• Emergency services can train and prepare for disasters
• Buildings can be designed to withstand earthquakes
• People can be educated about what to do if an earthquake or eruption happens
• Governments can plan evacuation routes
• Emergency supplies can be stockpiled

Question 39

What are some short term reliefs for after a tectonic disaster?

Answer 39

• Providing food, drink and shelter
• Treating people who have been injured
• Recovering dead bodies to stop the spread of disease
• Rescue people who have been trapped
• Provide temporary supplies of energy and communication if regular supplies have been damaged