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Flashcards in Component 1 Topic 1 Deck (21):

How does global atmospheric circulation lead to high and low pressure belts?

The global atmospheric circulation loops (called cells) are made from wind. These cells have warm rising air which creates a low pressure belt, and cool falling air which creates a high pressure belt.


Describe how ocean currents transfer heat around the earth

Ocean currents transfer heat energy from warmer to cooler regions. Surface currents are caused by winds and help transfer heat away from the equator. Deep ocean currents also transfer heat depending on water density. As frozen water gets denser it sinks and warm water rises to the surface.


How do high and low pressure belts create climactic zones

Sinking air from Hadley and ferrel cells meeting causes high pressure and prevents rainfall. Rising air from two Hadley cells meeting causes low pressure and lots of rainfall. Sinking air from the polar cells creates an area of high pressure, with low temperatures and little rainfall.


Describe how climate has changed from the beginning of the quaternary period to the present day.

During thee quaternary period global temperature has shifted between cold glacial periods that last for around 100,000 years and warm interglacial periods that usually last for around 10,000 years. Ever since the last glacial period around 15,000 years ago the global climate has been warming.


Describe how asteroid collisions might cause climate change

After impact of the asteroid on earth, huge amounts of dust gets thrown up into the atmosphere. The dust prevents the suns energy from reaching the earths surface meaning global temperatures will fall.


List 3 natural causes of climate change

Orbital changes, solar output and volcanic activity


Why are ice cores a useful source of information about past climate?

Ice cores can be used to show scientists the temperature of an area at a certain time period. Ice sheets are made up of layers and a new layer is formed every year. Scientists drill into ice sheets to get long cores of ice and by analysing the gas (e.g. carbon dioxide) trapped in the layers of ice they can tell what the temperature was each year.


What is the greenhouse effect?

The green house effect is the trapping of the sun's warmth in a planet's lower atmosphere.


Name two greenhouse gases

Carbon dioxide and methane.


Give four ways human activities increase the concentration of greenhouse gases in the atmosphere.

Farming- farming livestock releases a lot of methane into the atmosphere.
Energy- carbon dioxide is released into the atmosphere when fossil fuels are burned for energy.
Industry- most industry uses a lot of energy which releases a lot of greenhouse gases.
Transport- most cars and methods of transport release fossil fuels when being made and used.


Give three pieces of evidence for human activity causing climate change

Sea level rise
Decline in arctic ice
Global temperature rise


Give two possible future impacts of climate change on people.

Deaths (e.g. strokes) may occur due to an increase in heat and temperature.
Farming will become different throughout the world if temperature increases too much (e.g. maize crops have got smaller due to warming in recent years)


Why is it difficult to predict the impacts of climate change?

We cannot predict the future of climate change because we do not know how emissions will change. For example, society make change and decide to use less greenhouse gases.


What conditions are required for a tropical cyclone to develop?

Warm water (at least 26.5 degrees C)
The source area of most tropical cyclones is between 5 degrees and 30 degrees north and south of the equator.
The wind shear (difference in windspeed) between higher and lower parts of the atmosphere is low.


What can cause a tropical cyclone to dissipate?

When a cyclone travels over land or colder water it can dissipate because there is not enough energy to keep it going. Changes in windspeed may also cause the cyclone to dissipate.


Describe two impacts of tropical cyclones on people.

People may drown in the strong currents created by floodwater and storm surges. Very high windspeeds can also be strong enough to destroy buildings meaning people are left homeless.


Explain why some countries are more vulnerable to tropical cyclones than others.

Poorer countries are more vulnerable because buildings are poorer quality meaning they will be destroyed more easily. Poorer countries are economically vulnerable because many people rely on agriculture which is often badly affected by flooding.


Give three strategies that are used to prepare for and respond to tropical cyclones.

Forecasting- scientists can use satellites to predict when cyclones can hit and where their path will be. Warning strategies are used to alert people to a tropical cyclone and encourage them to evacuate. Defences such as sea walls are built to protect building inland from being flooded due to storm surges.


Describe the layered structure of the earth

At the centre of the earth is the core (This is a ball of solid iron and nickel, between 4400-6000 degrees C).

Around the core is the mantle (Silicon based rocks, between 1000-3700 degrees C).

The solid outer layer of the earth is called the crust (Silicon based rocks, made up of two crusts, Continental crust which is thicker and less dense, and Oceanic crust which is thinner and more dense).


Why do tectonic plates move?

Tectonic plates move due to convection currents in the mantle.


What is a convection current?

When lower parts of the asthenosphere heat up they become less dense and slowly rise. As they move up towards the top of the asthenosphere they cool down, become more dense, then slowly sink. These circular movements of semi molten rock are called Convection Currents.