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Natural Hazards (Tectonic Hazards (Why do people live in tectonically…

- - - - New crust is created, none is destroyed
      - Low magnitude earthquakes and volcanoes
    - - No volcanoes
      - High magnitude earthquakes
      - No crust is created or destroyed
    - - High magnitude volcanoes and earthquakes
      - Crust is destroyed but new crust is formed
  - - - Primary Effects
        
        500 dead, 12 000 injured, 800 000 affected
        
        220 000 homes destroyed, as well as 4 500 schools, 53 ports amnd 56 hospitals and other buildings
        
        Port of Talcahuano was destroyed
        
        Most of Chile lost power, water and communications
        
        Cost = US$30 billion
      - Background Information
        
        27th February 2010
        
        8.8 Moment Magnitude
        
        Destructive Plate Margin (Nazca moving towards South America)
        
        Waves in the Pacific Ocean reached 800km per hour
      - Secondary Effects
        
        1 500km of roads destroyed mainly by landslides - remote communities were cut off
        
        Several Coastal towns were devastated by tsunami waves as well as several Pacific countries (warnings prevented loss of life)
        
        A fire at a chemical plant near Santiago - area had to be evacuated
      - Response
        
        Immediate
        
        Emergency services acted swiftly. International help needed to supply field hospitals, satellite phones and floating bridges
        
        Temporary repairs made to the important Route 5 north-south highway within 24 hours, enabling aid to be transported from Santiago to affected areas
        
        Power and water restored to 90% of homes within 10 days
        
        A national appeal raised US$60 million - enough to build 30 000 small emergency shelters
        
        Long-term
        
        A month after the earthquake Chile's government launched a housing reconstruction plan to help nearly 200 000 household affected by the earthquake
        
        Chile's strong economy, based on copper exports, could be rebuilt without the need for much foreign aid
        
        The president announces it could take 4 years for Chile to recover fully from the damage to infrastructure
    - - Background Information
        
        25th April 2015
        
        7.9 Moment Magnitude
        
        Destructive margin (Indo-Australian Plate colliding with the Eurasian Plate at 45mm a year)
        
        Epicentre was 80km North-West of Kathmandu (15km below surface)
      - Primary Effects
        
        9 000 dead, 20 000 injuries, 8 million (1/3 of pop.) affected
        
        3 million left homeless, 7 000 schools and 50% of shops were destroyed
        
        1.4 million were left needing food, water and shelter
        
        International Airport was congested with aid
        
        Cost = US$5 billion
      - Secondary Effects
        
        Landslides & avalanches blocked roads and the Kali Gandaki River
        
        Avalanches on Mount Everest killed 19 people
        
        An avalanche in the Langtang region left 250 people missing
      - Response
        
        Immediate
        
        Search and rescue teams, water and medical support arrived quickly from countries such as UK, India and China
        
        Helicopters rescues many people caught in avalanches on Mount Everest and delivered supplies to cut off villages
        
        500 000 tents needed to provide shelter for the homeless
        
        Financial aid pledged from many countries
        
        Field hospitals set up to support overcrowded main hospitals
        
        300 000 people migrated from Kathmandu to seek shelter and support with family and friends
        
        Social media widely used in search and rescue operations and satellites mapped damaged areas
        
        Long Term
        
        Roads repaired and landslides cleared. Lakes, formed by landslides damming river valleys, need to be emptied to avoid flooding
        
        Thousands of homeless people to be rehoused and damaged homes repaired. Over 7000 schools to be re-built or repaired
        
        Stricter controls on building codes
        
        Jun 2015: Nepal hosted an international conference to discuss reconstruction and seek technical and financial support from other countries
        
        Tourism, a major source of income, to be boosted
        
        July 2015: some heritage sites re-opened and tourists were starting to return
        
        Repairs to Everest base camp and trekking routes
        
        August 2015: new routes had been established and the mountain re-opened
        
        Late 2015: blockades on the Indian border prevented supplies, medicines and construction materials reaching Nepal
  - - - Focus: the point of release of energy in the crust
  - - - Remote sensing - satellites detect heat and changes to the volcano's shape
      - Seismicity - seismographs record earthquakes
      - Ground deformation - changes to the shape of the volcano are measured using laser beams
      - Geographical measurements - detect changes in gravity as magma rises to the surface
      - Gas - instruments detect changes in gravity as magma rises to the surface
      - Hydrology - measurements of gases dissolved in water
      - There are no reliable ways to monitor or predict earthquakes
    - - Volcanoes - based on scientific monitoring
        
        Example: Eyjafjallajokull: in 2010 an increase in earthquake activity beneath it enabled scientists to make an accurate prediction about the following eruptions
      - Earthquakes
        
        It is impossible to make accurate predictions due to the lack of clear warning signs
        
        Scientists have identified areas at risk from historical records
    - - Volcanoes
        
        Earth embankments or explosives can be used to divert lava flows away from property
      - Earthquakes
        
        Reinforced concrete columns strengthened by a steel frame
        
        Tsunami walls protect important buildings such as nucleus power stations
        
        Shock absorbers absorb grand shaking
        
        Automatic shutters prevent broken glass from falling
        
        Rolling weights on the roof counteract shock waves
    - - Volcanoes
        
        Hazard maps show the likely areas to be affected around volcanoes
        
        This can be used in planning to restrict certain land uses or to identify areas that will need to be quickly evacuated
      - Earthquakes
        
        Maps can show areas most at risk, high-valued land uses can then be protected in the vulnerable areas
- - - - For example the Trade Winds in the tropics are responsible for driving tropical storms across these regions
  - - - Form 5-15 degrees north or south of the equator (at the equator there is not enough spin from the rotation of the Earth.
      - Form over oceans that are 27 degrees +
        
        Form in the Summer and Winter when sea temperatures are the highest
      - In tropical regions the intense heat makes the air unstable causing it to rise rapidly.These unstable conditions are important in the formation of hurricanes
    - - Distribution
        
        Sea surface temperatures in the tropics have risen by 0.25-0.5 degrees
        
        Tropical storms may affect areas outside of the current hazard zone
        
        March 2004: Hurricane Catarina hit the south-east of Brazil, the first ever storm recorded to do so
      - Frequency
        
        6 of the ten most active years since 1950 have happened since the mid-1990s
        
        Some computer models indicate that the frequency of tropical storms may decrease in the future, but the intensity may increase
      - Intensity
        
        Hurricane intensity in the North Atlantic has risen in the last 20 years - this appears to be linked with the increase in surface temperatures
    - - Typhoon Haiyan
        
        Background
        
        Philippines, November 2013
        
        Category 5 on the Saffir-Simpson scale
        
        Winds up to 170 mph
        
        Wave heights of 15 m
        
        Primary Effects
        
        6 300 people killed - mostly drowned by storm surge
        
        600 000 people displaced and 40 000 homes damaged
        
        Tacloban Airport terminal was badly damaged
        
        Buildings and power line damaged, crops lost
        
        400 mm of rain caused wide-spread flooding
        
        Secondary Effects
        
        14 million people affected, many left homeless and 6 million people lost their source of income
        
        Flooding caused landslides and blocked roads, cutting off aid to remote communities
        
        Power supplies in some areas cut off for a month
        
        Ferry services and airline flights disrupted for weeks - slowing down aid efforts
        
        Shortages of water, food and shelter
        
        Many jobs lost, hospitals damaged, shops and schools were destroyed
        
        Repsonse
        
        Immediate
        
        International government and aid agencies responded quickly with food aid, water and temporary shelters
        
        US aircraft carrier 'George Washington' and helicopters helped with search and rescue, as well as delivering aid
        
        Over 1200 evacuation centers set up
        
        UK government sent shelter kits
        
        French, Belgian and Isreali field hospitals set up to help the injured
        
        The Philippines Red Cross delivered basic food aid, which included rice, canned food, sugar, salt and cooking oil
        
        Long-term
        
        The UN and several countries donated financial aid, supplies and medical support
        
        Rebuilding of roads, bridges and airport facilities
        
        'Cash for work' schemes - people paid to clear debris and rebuild
        
        Foreign donors, including the US,Australia and the EU supported new livelihood opportunities
        
        Rice farming and fishing quickly reestablished, coconut farming took longer
        
        Aid agencies such as Oxfam supported the replacement of fishing boats - a vital source of income
        
        Thousands of home have been built away from areas at risk of flooding
        
        More cyclone shelters built
    - - Protection
        
        Windows, doors and roof reinforced to strengthen buildings
        
        Storm drains constructed in urban areas to take away excessive amounts of rainfall
        
        Sea walls built to protect key properties from storm surges
        
        Houses close to the coast constructed on stilts so that a storm surge will pass beneath
        
        Cyclone Shelters can be built
        
        In Bangladesh nearly 2000 have been built
      - Monitoring and Prediction
        
        Hurricane Watch - advises that hurricane conditions are possible
        
        Hurricane Warning - advises that hurricane conditions are expected and that people should take immediate action
      - Planning
        
        Dependent on raising awareness
        
        National Hurricane Preparedness Week in the USA
        
        Educating people on the potential dangers and how to respond
      - Bangladesh
        
        1970 - 500 000 death, 2007 - 4 234 deaths
        
        Early warning systems
        
        Cyclone shelters
        
        Bangladesh Meteorological Department track tropical cyclones
  - - - Thunderstorms - 2014: 3000 lightning strikes across Southern England | 2004: flash flooding associated with thunderstorms affected Boscastle in Cornwall
      - Prolonged rainfall - 2014: widespread rainfall across Southern England, common in the late Winter and early Spring when snow melt makes the problem worse
      - Drought/Extreme Heat - 2003: most extreme heatwave in 500 yrs, 20 000 people died in Europe
      - Heavy snow and extreme cold - long periods of severe winter weather have become less common in recent years, but there are occasions where heavy snow and sever cold can cause problems particularly in the north of the UK
      - Strong winds - sometimes the remnants of hurricanes travel over the Atlantic, these can disrupt power supplies
    - - Where are the Somerset Levels?
        
        South-west England, an area of low-lying farmland and wetlands
        
        Drained by several rivers, including the Tone and the Parrett which flow in to the Severn Estuary
        
        Flooding has occurred naturally here for centuries
      - Causes
        
        Wettest January since records began in 1910
        
        A succession of low pressure (depressions) driven across the Atlantic brought a period of wet weather lasting several weeks
        
        350mm fell in January and February
        
        High tides and storm surges swept further up the rivers from the Bristol Channel
        
        This prevented fresh water from reaching the sea and so spilled over the river banks
        
        Rivers has not been dredged in 20 years, so had become clogged with sediment
- - - - The Milankovitch Cycles
        
        Eccentricity
        
        The path of the Earth as it orbits the Sun.
        
        The Earth's orbit is not fixed - it changes from being almost circular to being mildly elliptical
        
        A complete cycle occurs about every 100 000 years
        
        Axil Tilt
        
        Over a period of 41 000 years the Earth tilt moves back and forth between the two extremes of 21.5 degrees and 24.5 degrees
        
        Precession
        
        A natural 'wobble' like a spinning top
        
        The Earth's wobble accounts for certain regions having really long days and nights at certain times of the year (like Norway)
      - Solar Activity
        
        Scientists have identified cyclical changes in solar energy output linked to the presence of 'sunspots'
        
        A sunspot is a dark patch that appears from time to time on the surface of the Sun
        
        The number of sunspots increases from a minimum to a maximum in a period of 11 years (this is called the sunspot cycle)
        
        When at maximum the Sun gives off more heat
        
        When at minimum less energy is given off
      - Volcanic Activity
        
        Volcanic ash can block out the Sun, reducing temperatures on the Earth - this tends to be a short-term impact
        
        The fine droplets that result from conservation of sulfur dioxide to sulfuric acid reflect radiation from the Sun - long-term impact
    - - Greenhouse Effect
        
        Heat is trapped in the Earth's atmosphere
        
        Caused by greenhouse gases: methane, water vapour and CO2
        
        Global concentration of CO2 accounts for 60% of the enhanced greenhouse effect
        
        Car Exhausts
        
        Deforestation and burning wood
        
        Burning fossil fuels
        
        Methane accounts for 20%
        
        Rice farming and livestock
        
        Burning biomass
        
        Decaying organic matter in landfill sites and compost heaps
        
        Nitrous Oxides make up a very small concentration
        
        Car Exhausts
        
        Sewage treatment
        
        POwer stations producing electricity
        
        Agricultural Fertilisers
  - - - Hydro-electricity
      - Nuclear power
      - Solar, wind and tidal power
      - The UK aims to produce 15% of its energy from renewable sources by 2020
    - - Uses technology to capture CO2 produced from the use of fuels in electricity production and industrial processes
      - It's possible to capture 90% of the CO2 that would otherwise enter the atmosphere
    - - Act as carbon sinks, removing CO2 from the atmosphere by photosynthesis
- - - - Droughts
      - Earthquakes
      - Tropical storms
      - Floods
    - - Must cause high levels of deaths/injuries/damage or disruption to be a "disaster"
  - - - Dependent Population
      - LIC migration
      - Urbanisation
        
        Population Density
    - - Poor quality
      - Poor construction
    - - Poor accessibility
    - - Poor access to services
      - Rebuilding is expensive
      - Poor access to clean water, energy ect.
    - - Proximity to plate boundaries
    - - Civil Wars
      - National Debt
      - Corruption