natural hazards

• What is the definition of a natural hazard?

  A natural hazard is an event caused by environmental processes that would occur without the presence of humans.
• What occurs when harm actually happens to the environment, people, or the economy?

  A disaster occurs when harm actually happens to the environment, people, or the economy.
• What are the categories of natural hazards based on their causes?

  • Tectonic
  • Geomorphological
  • Atmospheric
  • Biological
• Give an example of a tectonic natural hazard.

  Earthquake
• Give an example of a geomorphological natural hazard.

  Landslide
• Give an example of an atmospheric natural hazard.

  Tropical Storm
• Give an example of a biological natural hazard.

  Pests
• What does hazard risk refer to?

  Hazard risk is the chance that an area or population will be affected by a natural hazard.
• What factors affect hazard risk?

  • Population
  • Urbanisation and population density
  • Frequency and magnitude
  • Level of development
  • Prediction
  • Human activities
• How does population affect hazard risk?

  As the world population increases, more people live in areas vulnerable to natural hazards.
• Why does urbanisation increase hazard risk?

  Urban areas are more densely populated, increasing the numbers of people at risk.
• What do frequency and magnitude refer to in the context of hazard risk?

  Frequency refers to how often a hazard event occurs, while magnitude refers to the size and strength of the event.
• Why are some hazards difficult to predict?

  Some hazards, such as earthquakes, are impossible to predict, leaving people with no warning.
• How does the level of development affect hazard risk?

  High Income Countries (HICs) are more prepared and able to cope with the effects than Low Income Countries (LICs) and Newly Emerging Economies (NEEs).
• How do human activities increase hazard risk?

  Some human activities, such as deforestation and urbanisation, increase the level of hazard risk.
• What is the difference between a natural hazard and a disaster?

  A natural hazard is a potential event, while a disaster occurs when actual harm happens.
• What natural disaster caused the greatest number of deaths between 1990 and 2018?

  The 2004 Indian Ocean earthquake caused approximately 220,000 deaths.
• What is the main focus of the AQA GCSE Geography study material?

  Tectonic Hazards
• What are the four main layers of the Earth?

  • Inner core
  • Outer core
  • Mantle
  • Crust

  
• What is the diameter of the inner core of the Earth?

  About 1400 km

  
• What is the temperature of the inner core?

  About 5500°C
• How thick is the outer core?

  About 2100 km
• What is the state of the outer core?

  A semi-molten metal layer
• What is the thickness of the mantle?

  About 2900 km
• How does the density of the mantle compare to the outer core?

  The mantle is less dense than the outer core
• What is the thickness range of the crust?

  The thickness varies
• What are the two types of crust?

  • Oceanic crust
  • Continental crust
• How thick is the oceanic crust?

  5−10 km
• How does the density of oceanic crust compare to continental crust?

  Oceanic crust is heavier and denser
• How thick is the continental crust?

  25−90 km
• Why is continental crust much older than oceanic crust?

  Because oceanic crust is continually being created and destroyed
• What is the main focus of the AQA GCSE Geography study material?

  Weather Hazards
• What is the current theory of plate movement?

  • Slab pull theory
  • Movement is due to the weight of denser oceanic plates subducting
• What are the main topics covered in the Weather Hazards section?

  • Global Atmospheric Circulation
  • Tropical Storms
  • Effects of Tropical Storms
  • Management of Tropical Storms
  • UK Weather Hazards
• How does the global atmospheric circulation model function?

  It moves heat from the equator to the poles to balance temperature.
• What is a plate boundary or margin?

  Where two tectonic plates meet
• What causes wind formation?

  Air moves from high pressure to low pressure, generating wind.
• Why does the Sun heat the Earth's surface unevenly?

  Due to the Earth's curvature and angle of tilt.
• Where do most earthquakes occur?

  Along the Pacific 'Ring of Fire'
• What is the process of convection in relation to air movement?

  Hot air rises and cooler air sinks.