Geography paper 1

• A natural hazard can be defined as a natural event that has a social impact
• Types of natural hazards


  • Tectonic hazards (volcanoes, tsunamis, earthquakes)
  • Biological hazards (forest fires)
  • Geomorphological hazards (flooding, mudslides, rockslides)
  • Atmospheric hazards (hurricanes, tornadoes, lightning, rain)
• Why people live in hazardous areas

  • They don't want to leave
  • They believe defences will protect them
  • They don't believe the hazard will occur
  • Economic reasons (jobs, facilities)
  • Social reasons (don't know where to go, language barriers)
• Human activity impacts climate change

  Leads to more flooding and extreme weather events
• Tectonic plates


  Parts of the Earth's crust that are constantly moving
• Volcanoes and earthquakes are commonly found at fault lines where tectonic plates meet
• Oceanic crust


  Thin and less dense than continental crust
• Continental crust


  Thick and more dense than oceanic crust
• Types of plate margins

  • Destructive (continental-continental, continental-oceanic)
  • Conservative (plates move past each other)
  • Constructive (plates move away from each other)
• Primary effects


  First effects of a natural hazard on people and buildings
• Secondary effects


  After effects of a natural hazard over a longer timescale
• Immediate response


  How people react as the event is happening and immediately after
• Long-term response


  How people react in the weeks and months after the event
• High Income Country (HIC)


  Country with Gross National Income over $12,000 per person
• Low Income Country (LIC)

  Country with Gross National Income less than $12,000 per person
• Earthquakes in HIC countries

  • Chile (8.8 magnitude, $30 billion cost)
  • Italy (6.3 magnitude, $11 billion cost)
• Earthquake in LIC country

  • Nepal (7.9 magnitude, $5 billion cost)
• Mitigation measures for volcanic hazards include planning, evacuation plans, restricting land usage, emergency shelters, and educating the population
• Predicting volcanic eruptions is easier than predicting earthquakes
• Mitigation measures for earthquake hazards include mapping affected areas, locating critical infrastructure away from hazard zones, securing furniture, educating the population, and stockpiling supplies
• Mapping earthquake-affected areas


  • Identify areas that might be affected so hospitals and important buildings can be situated safely
  • Ensure buildings have furniture fastened down to reduce damage from flying objects
  • Educate local population on what to do in an earthquake
  • Stockpile food and medical supplies
  • Have earthquake drills to practice response
• Earthquake-resistant building design


  • New technology has enabled buildings to be designed to be more earthquake resistant
• Predicting earthquakes is much harder than predicting other tectonic hazards and there are no clear warning signs
• Some people think that animals can sense when earthquakes are about to occur and that their behavior will change because of it
• Smart phones have accelerometers and GPS which can be used to sense and detect earthquakes minutes before they occur
• Pressure belts


  Important factors that affect the world's weather
• Climate cells


  Important factors that affect the world's weather
• The tilt of the Earth and its rotation are responsible for seasonal changes in the positions of pressure belts and climate cells
• Locations and timing of tropical storms

  • Hurricanes in the Atlantic and eastern Pacific from August to October
  • Cyclones in the Indian and southern Pacific Oceans from January to March
  • Typhoons in the western North Pacific from May to December
• Tropical storms


  • Require low altitude, high temperature, high sea temperature, and sea depth of 60-70 meters to form
  • Form as air over warm tropical oceans is heated and rises under low pressure conditions
  • Coriolis effect causes air to spin around a calm center
  • Evaporated moisture condenses and cools as it rises, drawing more moisture upwards and forming large clouds and rainfall
  • Eye of the storm forms as cold air sinks, is dry and calm
• As temperatures and sea levels increase due to climate change

  Tropical storms become more frequent and destructive, with higher storm surges, increased rainfall, and more severe flooding
• Measures to reduce effects of tropical storms

  • Plan storm shelters, prepare disaster supply kits, educate population on response, install storm shutters/drains/sea walls, remove hazardous trees
  • Monitoring and prediction by National Hurricane Center and NOAA
• The UK experiences extreme weather hazards like snow, strong winds, droughts, and flooding
• Extreme weather in the UK is becoming more frequent and varied due to climate change caused by human activities
• Greenhouse effect


  Shortwave radiation from the sun warms the Earth, which then emits longwave radiation that is absorbed by greenhouse gases in the atmosphere, trapping heat
• Greenhouse gases


  • Carbon dioxide
  • Methane
  • Nitrous oxides
• Sources of greenhouse gas emissions

  • Combustion of fossil fuels (over 50% of global emissions)
  • Agriculture (around 20% of global emissions)
  • Deforestation
• Effects of climate change include increased flooding, decline in fishing industry, ice melt leading to habitat loss, and increased access to oil and gas
• One of the primary sources in releasing greenhouses gasses, particles, and water into the atmosphere is the combustion of fossil fuels
• Over 50% of global greenhouse gas emissions are from the combustion of fossil fuels