Structure of the Earth
- · 30 - 50km thick
- · Over 1500 million years old
- · Mainly granite, silicon + aluminium (SIAL)
- · Can't sink, can't be destroyed, less dense
- · 6 - 10km thick
- · Less than 200 million years old
- · Mainly basalt, silicon + magnesium (SIMA)
- · Can sink, can be destroyed, more dense.
Plate Margins (or boundaries): 4 types
- Constructive plate margins (A) - 2 plates move away from each other, magma rises to surface to form volcanic islands, volcanoes & earthquakes (both gentle).
- Destructive plate margins (B) - 2 plates move towards each other, denser oceanic crust sinks below cont. crust, causes deep ocean trenches, volcanoes & earthquakes (both violent).
- Collision zones (C) - 2 cont. plates move towards each other, neither can be destroyed so crush up to form fold mountains, no volcanoes but some earthquakes (mid to violent).
- Conservative plate margins (D) - 2 plates move alongside each other, in the same direction or different directions, violent earthquakes.
Plate Margin Case Studies
- Constructive - Mid-Atlantic Ridge, Iceland
- Destructive - Nazca & South American plate boundaries, Andes mountains (fold mountains), Peru-Chile Trench (8km deep, 45,00km long from Panama to Tierra del Fuego)
- Collision - Indo-Australian & Eurasian plate boundaries= Himalayas
- Conservative - Pacific plate (faster) & North American plate (slower), San Andreas Fault
Fold Mountains & Ocean Trenches
- many places e.g. Alps, Himalayas, Carcasas
- Rivers carry sediment into sea between 2 plates, sediments build on sea bed
- Geosycline filled with sediment, compression as plates move towards each other
- Continued compression from 2 plates, sediments folded into fold mountains
- found in subduction zones, edge of Pacific ocean e.g. Peru-Chile trench
- Oceanic plate sinks below cont. crust, causes a trench
Shield & Composite Volcanoes
Volcanoes found in long narrow belts e.g. 'Pacific Ring of Fire' & mid Atlantic ocean, south Europe & centre of Pacific ocean
- Constructive plate margins
- Lava - runny, basic, hot
- Cone - wide base, gentle slopes made of layers of lava
- e.g. Mauna Loa, Hawaii; Hekla & Heimaey, Iceland
- Destructive plate margins
- Lava - acidic, sets quickly
- Cone - tall, narrow base, steep sides made of layers of lava & ash
- Pyroclastic flows, secondary vents
- e.g. Mt St Helens, USA; Vesuvius, Italy.
Volcanoes- Monitoring and predicting
Warning signs (WS) and monitoring method (MM)
- WS- Swarms of small earthquakes (caused by the movement of magma through rock). MM- Seismometers detect the small earthquakes
- WS- Ground swellingand bulging (cause by magma rising). MM- Tilt metersrecognise changes of ground shapes
- WS- Gases released(Sulfur & CO2 from magma and steam from heat). MM- Spectrometermeasures Sulfur Dioxide
- WS- Increase inground temperature(rising magma heats up ground). MM- Thermal imaging satellitesdetect heat changes.
Nyiragongo (in the Congo)- Volcano
Cause- 17 January 2002- Constructive Plate boundary, in the Democratic Republic of Congo. Located on the African Plate, which is being torn apart by convection currents ß à
· EFFECTS- Primary: Lava flows reached speeds of 50mph, which split the city of Goma in half. 14 villages destroyed by lava flows. 50 people were killed when a petrol station exploded. Lava covered 15% of the city of Goma and destroyed 30% of the city, destroying many homes and businesses. 45 schools destroyed. Goma airport was closed and fuel tanks exploded.
· Effect- Secondary: 24,000 children out of school, so no education. 120,000 people homeless. Lava cooled into think layers of rock in Goma, so roads and houses blocked. Looting happened by armed gangs.
· RESPONSES- Immediate- People evacuated- 400,000 fled from Goma into neighbouring Rwanda to escape the lava. Diseases such as cholera spread because of lack of sanitation in refugee camps. The majority of evacuees moved back to Goma, within 10 days. 600 orphans given shelter by UN, until families can be found. UN provided shelter, food and blankets for 60,000 families.
· RESPONSES- Long term- The Government and UN began rebuilding the 45 schools destroyed by lava flows. Scientists and volcanologists attempted to get the city of Goma moved, but they failed. Chinese government workers rebuilt the roads in 2011. Local people run tours of the volcano for £200, which provides jobs and money for local economy. A Risk Management Unit was set up to scientifically monitor volcanic activity and estimate the risk level.
- erupts at least 1000km3 of material
- Huge magma chamber, grows to enormouse size & colossal pressure
- when it erupts & collapses, it causes a huge depession called a caldera
- Far wider than normal volcano, and flatter.
Facts: north-west Wyoming, USA; 55km by 65km- Tokyo city could fit in it; recurrence interval of 600,000 years; geysers, mud pits & hot springs; ground risen by 70cm in some places
Local effects - devastating for 100 mile radius; pyroclastic flows travel 100miles (kill 87,000 people); Ash would fall up to 10 feet deep, collapsing buildings; inhaling ash is dangerous; animals & crops die; day turns to night
National effects - north-west USA devastated; ash particles stay in air for years, crops fail for 6 years, biggest supplier of grain so big consequences. Up to 500,000 people killed by ash
Global effects - severe air traffic disruption; Ash arrive in Europe after 5 days, ash and sulphur aerosols decrease global temperature by 12-15 degrees= crops destroyed= major famine = thousands of deaths.
- Shaking of the ground, caused by sudden release of pressure due to movement along faults
- 90% occur along plate margins, strongest at destructive, collision & conservative.
- Plates push against each other and get stuck due to friction.
- Pressure builds up, until the plates suddenly move- the point of release is called the focus.
- Epicentre is the point on surface above the focus.
- Seismic Waves: Primary waves arrive first, then secondary waves, then surface (Rayleigh and Love) waves.
- Rayleigh waves arrive last and are most destructive.
- Measures: Energy released (size of seismic waves- the Magnitude)
- Measured using: Seismometer
- Scale: 0 to 10 (logarithmic scale= 3.0 is 10 times stronger than a 2.0)
- Other: Only 1 value is given for each earthquake (i.e. 7.2 magnitude)
- Measures: Damage caused
- Measured using: Observation by a human
- Scale: I (only felt by seismometers) to XII (total destruction)
- Other: Value varies depending on distance from epicentre
LEDC Earthquake: Haiti, 2010
FACTS: Haiti is on the margin of the Caribbean and North American plates (conservative plate boundary)
Richter Scale (7), Mercalli Scale (IX- 9), Epicentre 15km from city of Port au Prince
EFFECTS- Primary: 220,000 killed. Half of Haiti’s schools and three main universities collapsed, along with hospitals. 90% of Port-au-Prince’s buildings had been destroyed, incl 13 of 15 government offices.
EFFECTS- Secondary: 1.3 million became homeless. Damage to homes and businesses= $7.8 billion. 600,000 people fled to the countryside, and had to live in refugee camps. Due to bad conditions in refugee camps, there was an outbreak of Cholera, which killed 6000 people. 4,000 prisoners escaped, when the prison was damaged in Port--au-Prince’. There was looting and violence, due to the lack of police or law, as the Government was unable to coordinate any rescue attempts. Charities could not help people as roads were blocked and airport destroyed.
RESPONSES- Immediate: After 2 days, US soldiers took over the airport, and landed 2,500 aid flights table using only hand radios. American Red Cross raised $7 million in 24 hours by text messages. 5 days later, US Navy ship USS Carl Vinson arrived in port, and used helicopters to hand out drinking water and medical help. USA deployed 22,000 troops within 7 days to try and establish security and law, and stop the crime and looting. Within 2 days, 1000 bodies had been placed on the streets and pavements, then buried in mass graves.
RESPONSES- Long term: It took charities and the Government 4 years to clear all the rubble from the streets (8 million trucks full of rubble). Months after the earthquake, thousands of Port-au-Prince residents began returning to the rural towns they came from originally. 5 months later, the Haitian president resigned, due to corruption, and the UN deployed 10,000 troops to help recovery. 300,000 severely damaged buildings had to be demolished over 4 years. Only $2.38billion of the $4.5 billion promised to Haiti to rebuild the country has been given to it by the charities.
MEDC Earthquake: Christchurch, NZ (2011)
Richter Scale (6.3), Mercalli Scale (X- 10), Epicentre 10km from city of Christchurch.
EFFECTS- Primary: 181 people were killed (94 people were lost in the Canterbury Television Building) and around 2,000 people were injured. 50% of Central City buildings severely damaged including the city’s cathedral which lost its spire
· EFFECTS- Secondary: Liquefaction (where the ground gets saturated and loses strength) caused lots of damage to roads and buildings. 80% of the city had no electricity. Estimated $5 billion in damage
· In the seconds, hours and days after the earthquake rescue and response was offered by ordinary people as well as the emergency services on duty. The Canterbury Art Gallery (earthquake proof) was used as the government emergency Response centre. 300 Australian police were flown in to help emergency rescues.
RESPONSES- Long term: Christchurch could no longer host Rugby World Cup matches so lost the benefits, e.g. tourism and income, they would bring
Indian Ocean Tsunami (Boxing Day)
Location - epicentre under sea, 100km from Sumatra
Magnitude - 9.1 Richter scale, 10m vertical displacement of seabed along 750 mile fault line
Date - 26 Dec 2004
Effects - highest wave 25m; 220,000 died, 650,000 injured; 2 million homeless; no fresh water= dieseases (cholera and dysentery); tourist resorts damaged, affected local economy; many foreign nationals died; fishing boats destroyed (=no income for fishermen); roads blocked by debris, so emergency services could not get around.
Responses- Immediate: rescue services & emergency teams swamped by scale of disaster (local people searched and rescued people); 600 experts (rescue, medical and forensic scientists) sent from overseas to help; 5million people put into refugee camps and given help (water & shelter) by foreign countries, UN World Food Programme provided food for 1.3 million people.
Longterm - Indian Ocean Tsunami warning system built (cost $20 million); Mangrove swamps rebuilt as a barrier and breeding ground for fish (=economy); 20,000 new homes built; Local people were trained, so they could help out in future tsunamis; world gave £5billion given in aid for reconstruction.
Globalisation= the process of all the world's countries (incl economies) becoming integrated (linked together), by culture, information, business, etc. Countries have become interdependent as a result- they rely on each other for resources and services.
Reasons for Globalisation:
Improvements in ICT/ Communications:
- Email, the internet, mobile phones and phone lines carry more information quicker and faster, so businesses can communicate and can have headquarters in one country and communicate with branches in other countries (LEDCs).
- Cheaper = 98% reduction in price since 1930.
Improvements in Transport:
- More airports, high-speed trains and larger ships
- Quicker and easier for people all over the world to communicate face to face (can fly to meetings), and to transport goods.
- Cheaper= 80% reduction in price since 1930 .
Development of Call centres abroad
- Call centres are used by some companies to answer telephone enquires about their business (i.e. Lloyds Bank, etc)
- Improvements in ICT mean that its just as easy for people to phone a faraway country as it is to phone people in their own country
- Call centres are based in poorer countries:
- Salaries for workers there are cheaper= lower costs= more profit.
- Operating Costs (rent, electricity, equipment, etc) are cheaper= more profit
In 2013, Aviva (insurance company) moved 600 call centre jobs from UK to India, to save £400million:
- Call centre salaries in India (£3,000per year) lower than UK (£16,000per year)
- 90% of Indian graduates fluent in English
- Operating Costs 50% less that the UK
- Call centre jobs highly sought after= 2-3 times the average salary= middle class= low staff turnover.
Small Regions with Global Connections- Motorsport
MotorSport Valley, Oxfordshire, UK: World famous for motor-racing and Formula 1- close to Silverstone race track (so can test the cars) and the area has lots of skilled workers
- Small area of UK, but is connected with and trades with whole world (due to ease of ICT/ Transport).
- Employs over 40,000 people, and exports £5billion of goods around world.
- Has 8 of 11 F1 teams, incl Mercedes, Caterham, RedBull, Mclaren, Lotus and Renault.
- 3,500 motorsport companies based there.
- Close to airports, so can fly people and equipment anywhere quickly.
TNCs are companies that operate in more than 1 country around the world.
- TNCs love globalisation= cheaper costs/ salaries and more customers to buy things!
- TNCs normally have their headquarters (HQ) in a MEDC, as there are more people with better administrative skills (education is better).
- TNCs normally manufacture their products in an LEDC (as wages and Operating Costs are cheaper).
- All of this= MORE PROFIT (main objective for all companies)
20 Biggest TNCs in world (by revenue):
- Biggest TNC= Walmart (£380billion per year, which is larger than 80% of world's economies!)
- 50% of top 20 TNCs are Oil & Gas companies.
- Of the 20 biggest TNCs, 5 are US, 3 are Chinese, 2 Japanese, 2 German, only 1 British.
- Toyota= 13th biggest, Apple= 18th biggest.
Advantages and Disadvantages of TNCs
- Create jobs in LEDCs where they operate ("Host" country)
- Workers in LEDCs get higher and more reliable wages (INCOME), compared to farming
- TNCs spend money to improve the local infrastructure (schools, hospitals, roads, etc) in LEDC.
- TNCs bring new technology (e.g. factory machines, computers, etc) and skills to LEDCs.
- Profits generate normally sent back to "Home" country (normally a MEDC)- good for Home country (MEDC)
- Workers in LEDCs may be paid lower wages than employees in richer countries (no minimum wage)
- Workers in LEDCs may have to work long hours in poor conditions (little or no rules about working hours)
- Profits are sent back to the "Home" country (MEDC) and aren't reinvested in the LEDC they operate in (called LEAKAGE= money "leaks" back to MEDCs)
- Jobs created in LEDCs aren't secure- the TNC could move their factory & jobs to another country, if they find somewhere else is cheaper.
- Jobs are lost in MEDCs when the TNC moves overseas.
TNC Case Study- Wal-Mart
· Created in 1962 and originally based in USA
· Largest TNC in the world- serves 200 million customers a week.
· 9600 stores operating across 28 countries
· Revenue in 2013= £400billion= bigger than economies of 160 countries!!!!
Advantages: Jobs- Walmart employs 2.1 million people worldwide, incl 1% of USA!
· Walmart were the first store to reduce product packaging (cardboard)= less waste and better for the environment.
· Wal-Mart donates money to improve healthcare, education and the environment in the countries it is based in- they gave £1 billion in 2012.
· Factory workers in the USA earn around £5 an hour but factory workers in China only earn £1 an hour, where production runs 24/7 (exported $18 billion worth of goods from China to USA in 2004 alone)
· Unfair distribution of profit- something assembled in a Chinese factory for 18p is sold for at least £13 in Walmart stores.
· Employs 189,000 females in Bangladesh working in horrible conditions, and v long hours.
Manufacturing industry growth
MEDCs seeing a decline in industry (manufacturing)- “de-industrialisation”. NICs and LEDCs seeing a large increase in industry (manufacturing)- “industrialisation”.
Reasons for move to NICs/ LEDCs:
- Cheap labour: No or lower minimum wage. Philippines- average factory worker £7 per day (UK £60 per day).
- Working hours: Less rules= longer hours. South Korea- average 2400 hrs per year (UK 1600 hrs).
- Health & Safety: less rules= cheaper to operate. Do not need to provide protective equipment. Workers sometimes sleep in factories.
- Pollution: less rules= cheaper to operate. Many TNCs could not afford to follow environmental regulations in MEDCs (i.e. German Chemical TNC Celanese could not afford to have its chemical factory in Germany, as would be fined for fumes released).
- Tax Incentives: TNCs can pay reduced tax (tax reduction) or no tax (tax-free) if they move their factories to an area= more profit for TNC!
- Unions not so powerful= workers groups (unions) have less power= not so many strikes.
Lower WAGES + Longer HOURS + Lower OPERATING COSTS + Less TAX= MORE PROFIT
Graph Showing Manufacturing industry Growth
Case Study- China 1
The World’s 2nd largest economy in 2013 (predicted to overtake USA as the largest in 2030 )
· Produced 7% of all world manufacturing output
· By 2030, it could control 25% of the global economy
· China’s economy has doubled in value every 8 years for the last 30 years
· Largest consumer of raw materials in the world
- China is a Communist state= government controlled most things: banks, farming, large heavy industries and public services, and no opposition parties were allowed.
- 1979- Government changed laws, to allow investments from overseas TNCs (as country was never going to modernise, and get wealthier, without new machinery, skills and modern technology).
- China changed from being a mainly agricultural (farming) economy to the world’s largest manufacturer (2013) in under 35 years.
Case Study- China 2- Reasons for Growth
Reasons for Growth:
- China opened up to international trade in 1977, by changing laws, and inviting TNCs
- 1978- 1994: Special Economic Zones (SEZ) set up (such as Shenzhen)
- Offered tax incentives to attract foreign TNCs (usually pay no tax for the first two years in the zone, 7.5% for the next three years and then 15% from then on. Normal Chinese tax= 30%)
- Offered “capitalist” local economy= less controlled by Chinese Gov= more attractive to TNCs
- Foxconn employ over 300,000 people in Shenzhen making iPhones for Apple.
- One Child Policy led to smaller families= more disposable income= more consumer demand for products in China.
- Chinese middle class (25% of population) is fastest growing in world= more demand for consumer products= more factories needed to make products for this “home” market.
- Cheap labour is a key reason- wages are 95% lower than in the USA.
- Longer working hours- Chinese law states that workers should work for a maximum of 40 hours a week with 36 hours of overtime per month (but not enforced= Foxconn made workers work 80 hr weeks)
Global demand for energy
Social and Economic Impacts
- more power plants will have to be built to increase energy production- power plants extremely large so people may have to move out of an area
- the waste from nuclear power plants is radioactive, if it leaks out from where it is stored it can cause death and illness and contaminate large areas of land,
- if more nuclear power plants are built to increase energy production there is a higher risk of radioactive waste leaking out
- increasing energy production will create jobs, people will be needed to build more power stations, run and maintain them
- countries with lots of energy resources e.g. lots of coal, will become richer as energy demand increases- countries with few resources will need to buy energy from them
- Burning fossil fuels releases carbon dioxide, this adds to global warming, global warming will cause the sea level to rise and more severe weather and force species to move or make them become extinct
- burning fossil fuels releases other gases that dissolve in water in the atmosphere and cause acid rain which can kill animals and plants
- gathering wood for fuel can cause deforestation which destroys habitats for animals and plants
- mining for coal causes air and water pollution, it removes large areas of land which destroys habitats
- transporting oil is risky as oil pipes and tankers can leak, spilling oil which can kill birds and fish
- Before the 1960s people mainly ate a small range of seasonal food that had been grown in their own country or local area
- people now demand to have a range of foods all year round, regardless of growing seasons- this has led to the globalisation of the food industry- food is produced in foreign countries and imported
- the increase in the world's population also means more food is needed- demand has increased
- countries are trying to increase food production to meet this demand, but some can't produce enough to feed their population so food has to be imported too
- transporting food produces CO2-
- food miles= the distance food is transported to the market
- the higher the food miles, the more CO2 produced
- carbon footprint= the amount of CO2 produce during growing and transporting, a larger carbon footprint means more CO2
- imported foods have to be transported a long way so have high food miles and a large carbon footprint.
- benefit of importing food means that a wide range of food is available all year round, also it helps meet the increasing demand
- more food could be produced locally by energy intensive farming- pesticides, fertilisers and machinery to produce large quantities of food, but although food miles are low, loads of energy is needed to make the chemicals and run the machinery- energy production creates lots of CO2
- to produce more food some farmers use marginal land (land that is not really suitable for farming e.g. steep hillsides and deserts) the soil in marginal land is thin and it's quickly eroded by farming, degrading the environment
- lots of water is needed to produce lots of food
- farmers in countries with low rainfall need to irrigate their land with water from rivers and lakes
- as demand for water increases there may be hostilities between countries that use the same water source for irrigation
- e.g. there is tension between Egypt, Sudan and Ethiopia because they all take water from the river Nile
- some farmers are switching from subsistence farming to commercial farming this is because they can make more money due to the high demand for food
- this reduces the amount of food produced for the local people so the have to import- which is more expensive
- if food prices go down, then farmers might not earn enough money to buy food for themselves
- using chemicals helps to produce lots of food but these chemicals can be very expensive- farmers may have to borrow money to buy the chemicals and this gets the farmer into debt
- farmers can generate a steady income by producing food for export to other countries
- energy production needs to be sustainable- it needs to allow people alive today to get what they need but without stopping people in the future getting what they need
- producing energy using fossil fuels is unsustainable
- fossil fuels are non-renewable so they will eventually run out and there won't be any for future generations
- using fossil fuels damages the environment- burning them produces CO2 which causes global warming
- energy produced from renewable sources is sustainable because it doesn't cause long term environmental damage and the resource won't run out
- producing energy from renewable sources contributes to sustainable development
Renewable energy sources
wind wind turns blades on wind turbine to generate electrical energy
biomass biomass is material that comes from organisms that are alive or recently alive, it can be burnt to release energy it can also be processed into biofuels which are then burnt to release energy
solar power energy from the sun can be used to heat water, cook food and generate electrical energy
hydroelectric power- water is trapped behind a dam and forced through tunnels turning a turbine to generate electricity
- harnessed using a tall pylon fitted with blades to catch the wind
- the energy of the moving blade is turned into electricity in the nascelle
- the nascelle turns so the blade face into the wind
- usually built together in wind farms
- energy goes straight to electrical grid or directly to the user
need to be sited:
- strong and reliable- average wind speed no less than 5mper second
- away from obstructions which obstruct flow
- on flat ground- hilly terrain causes turbulence and reduces wind speed
- away from natural parks or areas of outstanding natural beauty
Case Study- Spain
Spain's energy consumption has increased by 66% since 1990
some of the extra energy needed is being produced using wind turbines- has increased 16 times as much since 1995
Spain is ideal for wind farms because it has large, windy areas where not many people live- so won't disturb and annoy too many people
Spain has over 400 wind farms and a total of over 12,000 turbines
in 2008, 11.5% of Spain's energy was supplied by wind turbines
Case Study- Spain, Impacts
- in 2008 using wind energy reduced Spain's CO2 emissions by over 20 million tonnes
- in 2008, using wind energy saved Spain from importing about £2.1 billion of oil and gas
- Spain's wind industry has created about 40,000 jobs
- some conservationists say the wind farms are a danger to migrating birds
- some people think wind farms are ugly- they can be seen from miles away
- some people think they are too noisy
The Kyoto Protocol
Globalisation has increased the demand for energy, more fossil fuels are being used to meet the demand producing loads of CO2 and adding to global warming
the international community is working together to reduce the amount of CO2 they produce because the problem of global warming is that is affects everyone
The Kyoto Protocol is an international agreement that has been signed by most countries to cut emissions of CO2 and other gases by 2012. each country is set an emissions target e.g. the Uk has agreed to reduce emissions by 12.5% by 2012
another part of the protocol is the carbon credits trading scheme:
- countries that come under their emissions get carbon credits which they sell to countries that aren't meeting their emissions target- reward for low emission
- countries can also earn carbon credits by helping poorer countries to reduce their emissions- means poorer countries will be able to reduce emissions quicker
Other international agreements
- globalisation has increased the emission of gases that cause pollution like acid rain
- there are international agreements that help reduce pollution e.g. Gothenburg protocol
- The Gothenburg Protocol sets emissions targets for European countries and the US, it aims to cut harmful gas emissions by 2010 to reduce acid rain and other pollution
- globalisation means people have access to more products at low prices so people can afford to be more wasteful e.g. people throw away damaged clothes instead of repairing them
- things that are thrown away are taken to landfill sites and the amount of waste going into landfill has increased along with globalisation
- one way to reduce this impact is on a local scale is to recycle waste to make new products e.g. recycling old drinks cans to make new ones
Buying local produce
- In recent years celebrity chefs, food writers and campaigners have encouraged people to eat more locally-produced food
- buying local food helps to reduce food miles because it hasn't had to be transported a long way and it also helps to support local farmers and businesses
- however if people only buy locally it can put people in poorer countries that export food out of a job