Paper 1 Topic 1: Hazardous Earth

Atmospheric circulation redistributes heat energy around the Earth. - High pressure = sinking air = dry and calm conditions (around the tropics and poles) - Low pressure = rising air = wet and unsettled conditions (around equator and also over UK!) Ocean currents also redistribute heat. For example, the Gulf Stream transfers warm weather from the Caribbean Sea across the Atlantic to the UK. This is because cold water in the North Atlantic sinks and warm water from the Caribbean fills the space.

REMEMBER: equator has higher temperatures as solar radiation is direct and spread over a smaller surface area.

Inter-tropical convergence zone: warm air meets and rises, leading to rapid condensation & therefore heavy rainfall &high winds.

Natural Causes of Climate Change

Orbital changes (long-term)

- Every 100,000 years the Earth’s orbit becomes elliptical (or egg-shaped)

Solar output (medium-term)

- Sun’s output is not constant; when there are lots of sunspots more energy is given off; meaning Earth’s temperature is higher; sunspots appear on 7 year cycle

Volcanic activity (short-term)

- After major volcanoes ash and dust particles ejected into atmosphere; this blocks sun’s radiation; so temperatures drop

EVIDENCE:

1. Long-term (100,00 years): oxygen isotopes in ICE CORES show us periods of time when it was warmer

2. Medium term (500-1,000 years): a wider TREE RING means more growth due to warm and wet conditions; farming documents and paintings of frost fairs are HISTORICAL RECORDS that give clues about past climate

3. Recent (last 200 years) – accurate CLIMATE DATA taken by instruments.

Global warming: - Greenhouse gases absorb outgoing radiation and warm the planet; this is the greenhouse effect (natural) - Without greenhouse gases the earth would be 30°C colder - However, human-produced greenhouse gases are creating an enhanced greenhouse effect (manmade) - This means too much warmth is being kept in; this will get worse unless we change our lifestyle

Greenhouse Gas: Human Activity: Explanation:

Carbon Dioxide 1800 = 280 ppm 2018 = 400 ppm (parts per million)

Deforestation Trees give out oxygen and store carbon; when trees are destroyed carbon is released into the atmosphere

Driving Cars Cars use petrol; petrol is a fossil fuel made from oil, therefore when burnt carbon is released into the atmosphere

Methane 1800 = 700 ppm 2018 = 2000 ppm (parts per million)

Farming cattle (cows)

When cows give off wind methane is released into the atmosphere; more and more cows are being farmed as there is an increased demand for meat; it is estimated that 11% of Australia’s carbon footprint is due to cattle giving off wind.

Global Warming – the evidence. Conclusion = NATURAL FACTORS PLAY A PART BUT HUMANS ARE MOSTLY TO BLAME DUE TO THE RAPID RATE OF CHANGE AND FACT THAT THIS CHANGE HAS COINCIDED WITH INDUSTRIALISATION. Since 1990: Temperatures increased by 1°C / sea level rise of 8cm / more frequent + intense tropical storms / shrinking ice sheets

FACTORS THAT EFFECT POSSIBLE FUTURE CHANGES IN CLIAMTE:

? Future population growth? ? Switch to renewables? ? Continued industrialisation? ? New technology to reduce emissions?

Explain how tropical storms are formed. (4)

1. Tropical storms will only form over warm water (over 26°C) with a sufficient depth (over 50m).

2. This large mass of warm water heats the air above the sea and causes it to expand, creating an area of low pressure.

3. The surrounding air rushes in to fill the void.

4. Due to the rotation of the earth (known as the Coriolis Force) the rising air masses rotate as they are pulled in.

5. This leads to the strong winds. As the air spirals upwards, the warm air cools down and rapid condensation occurs, which leads to high levels of precipitation.

6. Tropical storms will only form at least 5° north or 5° south of the equator.

7. This is because any closer to the equator, the Coriolis Force will not be strong enough to cause the rotation of the air masses.

Tropical storms form in the ITCZ – they need warm water, humid air, rapid cooling and sufficient Coriolis force. They dissipate as they lose

water supply as they hit land, or when the water becomes too cold, or if winds start blowing in different directions.

Tropical storm hazards 1. High winds 2. High rainfall 3. Storm surge due to low pressure 4. Landslides

The Philippines has high vulnerability to tropical storms because… Physical Low-lying; islands so large coastline; hard to travel between islands Social Lack of access to shelter, food and medicine; poorly educated on how to respond; high prop. of children Economic Low incomes to respond, evacuate, recover; no technology to predict; no coastal defences

Tropical Cyclone in a DEVELOPED Country - Hurricane Katrina – USA - Magnitude: Category 3 at landfall - Place: South East USA inc. New Orleans - Date: 29th August 2005

- Tropical Cyclone in a DEVELOPING Country - Cyclone Nargis – Myanmar - Magnitude: Category 4 at landfall - Place: Irrawaddy Delta, Myanmar - Date: 2nd May 2008

How do both countries use FORECASTING and SATELLITE

TECHNOLOGY to prepare for cyclones?

- The USA has a sophisticated monitoring system to predict if and where a hurricane will hit.

- The National Hurricane Centre (NHC) in Florida tracks and predicts hurricanes using satellite images and planes that collect weather data on approaching storms.

- Myanmar doesn't have a dedicated monitoring centre for tropical cyclones.

- Myanmar doesn't have a radar network that can predict the height of storm surges and waves caused by cyclones.

How effective were WARNING & EVACUATION

strategies?

- The NHC issued a hurricane warning on 26th August for Louisiana. Mississippi and Alabama. It continued to track the hurricane, updating the government on where and when it would hit.

- Mississippi and Louisiana declared states of emergency and 70-80% of New Orleans residents were evacuated before the hurricane reached land. This reduced the number of people killed because lots of people had left the areas where the hurricane hit.

- Indian weather agencies warned the government of Myanmar that Cyclone Nargis was likely to hit the country 48 hours before jt did.

- Warnings were issued on the TV and radio, but they

didn't reach people in poor rural communities. This meant more people were killed because they didn't know what to do or where to evacuate to.

- There were no emergency preparation plans, no

evacuation plans and the country didn't have an early warning system.

How effective were the STORM- SURGE defences?

- The city of New Orleans was very badly damaged — flood defences (e.g. embankments) that were supposed to protect the city failed.

- This caused widespread flooding (over 80% of the city was underwater).

- Mangrove forests protect the coast from flooding, but loads had been chopped down in the decade before Nargis hit reducing the natural protection.

How effective was the

PREPARATION and RESPONSE? –

ENVIRONMENTAL

impacts of the cyclones

- Coastal habitats such as sea turtle breeding beaches were damaged.

- Some coastal conservation areas were destroyed, e.g. around half of Breton National Wildlife Refuge in Louisiana was washed away.

- Flooding damaged oil refineries in Louisiana, causing massive oil spills.

- The Irrawaddy delta in Myanmar was the hardest hit area — a large proportion of it is only just above sea level and 14 000 km2 of land was flooded.

- 38 000 hectares of mangrove forests were destroyed.

- The flooding caused erosion

How effective was the

PREPARATION and RESPONSE? –

Impacts of the

cyclones

- More than 1800 people were killed. - 300 000 houses were destroyed and hundreds of

thousands of people were made homeless. - 3 million people were left without electricity. - Roads were damaged and some bridges

collapsed.

- More than 140 000 people were killed. - 450 000 houses were destroyed and 350000 were

damaged. - Around 65% of rice fields in -the Irrawaddy Delta

were damaged, which led to a loss of livelihoods. - Many people suffered from diseases caused by poor

sanitary conditions and contaminated water. What has been improved since the cyclones?

- All of New Orleans’s 400km of levees have been made much higher and much stronger.

- All the city’s 78 floodwater pumping stations have been made flood-proof.

- A barrier has been built to protect New Orleans – the largest storm surge barrier in the world.

- Upgrading the responses cost $14 billion. - New funding has been spent on search and

rescue teams and residents get evacuation updates by text message.

- International aid organisations have built much stronger schools, hospitals and homes.

- Local communities now have special committees to organise evacuations.

- The government has built 20 cyclone shelters, each for 500 people.

- Two people in each community are given a mobile phone so they can relay cyclone warnings.

Continental Crust Oceanic Crust

0-100km (Thicker)

0-20km (Thinner)

Less dense More dense

Slow cooling granite rock with large

crystals

Fast cooling basaltic rock; dark in colour

Explain why the earth’s crust is constantly moving?

1. The earth’s crust is made of different plates. 2. The core of the earth is hot due to the pressure from the overlying material and the radioactivity of the material in the core (such as uranium). 3. The heat in the core causes circulating movement of magma in the mantle, known as convection currents. 4. The flow of convection currents in the asthenosphere (upper part of mantle) moves the plates that make up the earth’s crust.

Along edge of continents

Through middle of oceans

Exception to the rule; through continents

Nazca plate subducted under South America

Eurasian plate moves away from North American plate

Eurasian plate collides with Indo-Australian plate

Destructive

Constructive

Collision

Pattern Example Location Type of boundary / margin

Where are the plate boundaries generally located?

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Shallow Focus Earthquake Deep Focus Earthquake

- focus nearer surface (within 70km); more common; usually occur along constructive, collision (Kashmir, 2005) or conservative plate boundaries (e.g. Loma Prieta, 1989); usually of smaller magnitude

- much deeper (300km – 600km) as occur at subduction; less common; along subduction zones (e.g. around Japan); often large magnitudes (over 6 on Richter Scale)

Shield Volcano e.g. Mauna Loa, Hawaii - Frequent but often not violent - Usually constructive margin Basaltic magma - High temperature - Less silica and dissolved gas - Less explosive Shape - Fluid lava therefore gentle slope - No layers of ash as little material is destroyed during eruption

Magma chamber

Secondary flank vent

Layers of lava

Layers of ash

Central vent

Viscous magma Tall steep

sided shape

Composite Volcano e.g. Nevado del Ruiz, Colombia (1985)

- Less frequent but often violent - Usually destructive margin

Andesitic magma - Lower temperature

- More silica and dissolved gas - More explosive

Shape - Tall with steep sides as eruption less frequent

- A layer of lava forms after an eruption; on top of this is a layer of ash and rock debris caused by the

explosion destroying material around the volcano

Thousands

Has not erupted in thousands of years and is not expected to do so again

529

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Number:

Definition:

Category:

536 Has erupted in recorded history Active

Has not erupted in recorded history, but show evidence that they may do so again

Earthquake in a DEVELOPED Country Place: Sendai, Japan 2011 Magnitude: 9.0 Focus: 30km deep on a convergent plate boundary Epicentre: 70km from the coast in Sendai Bay

Earthquake in a DEVELOPING Country Place: Port-au-Prine, Haiti 2010 Magnitude: 7.0 Focus: 13km deep on a conservative plate boundary Epicentre: 25km from Port-au-Prince (population 2.5 million)

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• 1 dam collapsed, 2 nuclear power stations fractured, and an oil refinery set on fire by damaged gas pipes.

• Tohoku motorway badly damaged in northern Japan. Sendai airport closed by the tsunami. One rail link near Sendai badly damaged.

• US$ 235 billion of damage caused by earthquake and tsunami combined - the costliest disaster in history.

• 316 000 people died and a further 300 000 were injured. • Many houses were poorly built and collapsed instantly. 1

million people made homeless. • The port, communication links and major roads were

damaged beyond repair. Rubble from collapsed buildings blocked road and rail links.

SECO

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• Secondary effects (caused by the tsunami) • 15 900 people died, 350 000 homeless. • 93% of deaths caused by drowning. • Two nuclear reactors went into meltdown because

flooding damaged the cooling systems. Local people were evacuated and had not returned by 2015.

• unemployment and increased stress lasted for years as the authorities struggled to cope with damage.

• The water supply system was destroyed – a cholera outbreak killed over 8000 people

• Haiti’s important clothing factories were damaged. These provided over 60% of Haiti’s exports. 1 in 5 jobs were lost.

• By 2015 most people displaced by the earthquake had been re-housed.

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• International aid and search and rescue teams were brought in.

• Rescue workers and soldiers were sent to help deal with the aftermath.

• Transport and communications were restored a couple of weeks after the earthquake.

• Power supplies were restored in the weeks following the earthquake.

• Neighbouring Dominican Republic provided emergency water and medical supplies as well as heavy machinery to help with search and rescue underneath the rubble, but most people were left to dig through the rubble by hand.

• Emergency rescue teams arrived from a number of countries, eg Iceland. • Medical teams began treating the injured – temporary field hospitals were

set up by organisations like the International Committee of the Red Cross. • GIS was used to provide satellite images and maps of the area, to assist aid

organisations. • People from around the world watched the news from Haiti on TV and

through social networks.

EFFE

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of the earthquake and the tsunami, which gave people time to evacuate and get to higher ground.

• Nobody died on the bullet train network because of the automatic braking systems.

• Because there were few earthquake-resistant buildings, the devastation was massive. Many buildings simply collapsed or were damaged beyond repair.

PRED

ICTI

ON

• The Japan Meteorological Agency (JMA) and local governments monitor seismic activity all over the country.

• If an earthquake is detected, people are warned immediately.

• US Geologists said Port-au-Prince could be hit by a 7.2 magnitude but they couldn’t say with any certainty when this would take place.

PREP

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• Strict building laws help prevent major damage during an earthquake.

• Buildings are reinforced with steel frames to prevent them from collapsing.

• High-rise buildings have deep foundations with shock absorbers to reduce vibrations and shaking in the building.

• Japan has early warning systems to alert residents to earthquakes and tsunamis.

• High-speed 'bullet' trains automatically brake in the event of an earthquake to stop them derailing.

• There were no building regulations in Haiti • many Buildings in Haiti being built with poor quality, cheap

materials and these simply crumbled when the earthquake shook.

• 80% of education in Haiti was provided in often poor-quality private schools, the state system generally provided better education but provided far too few places

• Half of people in Port-au-Prince had no access to toilets and only one-third has access to tap water

LON

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• Japan's population is educated on being prepared for earthquakes, e.g. Disaster Prevention Day is an annual nationwide drill to practise evacuations in the event of an earthquake (September 1st).

• Schools carry out drills to teach children what to do if there is an earthquake.

• Haiti had no official emergency services so there were no trained emergency services , which made the rescue efforts chaotic and increased the importance of NGO help e.g. The Red Cross and International aid from countries like the UK and USA.

Practice Questions – Hazardous Earth

1a. Calculate the amount of damage caused by storms in $US. (1) 1b. Calculate the number of flood events. (1) 1c. Calculate the difference in number of deaths between storms and earthquakes. (2) 2a. Compare the impacts of storms across a range of indicators. (3) 2b. Explain why the Philippines may be more vulnerable to some hazards as opposed to others. (3) 3a. Define the term epicentre. (1) 3b. Define the term secondary hazard. (1) 4a. Describe the formation of a tsunami. (3) 4a. Compare two different types of volcanoes. (3) 5a. Explain how tropical storms are formed. (4) 5b. Explain why some earthquakes cause more deaths than others. (4) 5c. Explain one cause of natural climate change. (3) 5d. Explain one human cause of climate change. (3) 5e. Explain the processes and hazards associated with a conservative plate boundary. (4) 5f. Explain how atmospheric circulation and ocean currents redistributes the Earth’s heat. (4) 6a. Assess the view that developed countries are always well-prepared to deal with tropical storms. (8) (+4) 6b. Assess the statement: Impacts of tectonic hazards are always worse in developing countries. (8) (+4) 6c. Assess the causes of climate change. (8) (+4) 6d. Assess the factors which influence the number of deaths that result from tectonic hazards. (8) (+4) 7a. Evaluate the effectiveness of preparation and response to tropical storms in a developed country. (8) 7b. Evaluate the effectiveness of preparation and response to tropical storms in a developing country. (8) 7c. Evaluate the effectiveness of preparation and response to tectonic hazards in a developed country. (8) 7d. Evaluate the effectiveness of preparation and response to tectonic hazards in a developing country. (8)

Key Terms

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