paper 1 geography

• Natural hazard


  A natural event which negatively impacts people
• Categories of hazard


  • Geological/ Geophysical
  • Hydrological
  • Atmospheric
• Hazard risk


  The probability (likelihood) that a natural hazard will affect a population
• Urbanisation


  Increases hazard risk because urban areas are more dense with buildings
• Climate change


  Increases hazard risk as warmer oceans means increased intensity of tropical storms
• Wealth


  Decreases hazard risk as HICs can afford to prepare and protect
• Poverty


  Increases hazard risk as may live in unsafe houses & poor access to healthcare
• Oceanic crust


  • Younger
  • Dense
  • Can sink and be destroyed
• Continental crust


  • Older
  • Less dense
  • Cannot sink or be destroyed
• Convection currents in the mantle

  Cause the earth's plates to move
• Tectonic hazards generally occur along/near plate margins
• Plate movement at constructive margin

  Plates move away from each other
• Plate movement at destructive margin

  Plates move towards each other
• Plate movement at conservative margin


  Plates move past each other
• What happens at a destructive margin

  Plates move towards each other. Oceanic plate subducts & melts due to friction.
• What happens at a constructive margin

  Two plates move apart. Magma rises up to fill the gap.
• What happens at a conservative margin


  Two plates move past one another. They get stuck. Pressure builds.
• How earthquakes happen


  Plates move due to convection currents. 2. They do not move smoothly creating friction 3. Pressure builds. 4. Eventually slip & pressure released
• How volcanoes form at constructive margin

  Plates pull apart. 2. Gap created, plugged by rising magma. 3. Magma cools to create new land. 4. Repeats & layers build.
• How volcanoes form at destructive margin

  Plates move towards each other. 2. Oceanic plate subducts (denser). 3 It is destroyed due to heat & friction. 3. Magma rises through cracks. 3. Erupts on surface. 4. Lava cools & forms new rock.
• Japan's immediate responses


  • 100,000 soldiers for search & rescue, 20km evacuation zone. Tsunami warning siren after 3 minutes
• Japan's long term responses

  • 8m tsunami walls replaced with 14m ones, repaired Tohoku expressway
• Haiti's short term responses

  • UK gave £20 million, USA sent 10,000 troops, 1,500 temporary camps
• Haiti's long term responses

  • New homes built to a higher standard, farms given tools & seeds, port rebuilt
• Reasons people live near plate margins (GETFAN)

  • Government
  • Employment
  • Tourism
  • Farming
  • Always lived there & never happen!!
• 28% of Iceland's energy is geothermal
• 3000 buildings in Tokyo are earthquake proof
• Volcano monitoring


  • Remote sensing to detect changes to shape & collect/measure gasses (SO2), seismometers to detect EQ activity
• Volcano prediction


  Use monitoring data to identify when it is close to an eruption
• Protecting people from earthquakes

  • Earthquake proof buildings and infrastructure e.g. shock absorbers in foundations, pyramid shape
• Protecting people from volcanic eruptions


  • Explosives or embankments used to divert lava flow away
• Japan does earthquake drills nationwide on September 1st
• Global atmospheric circulation


  Movement of winds on earth; Hadley, Ferrel & Polar cells
• Wind direction


  Blows from areas of high pressure to areas of low pressure
• Tropical easterlies blow from East to West
• Location of tropical storms

  1. 30 degrees north and south of the equator
• How tropical storms form

  Air heated above oceans. 2. Warm, moist air rises rapidly under low-pressure. 3. Air rushes in creating strong winds. 4. Coriolis effect causes air to spin around calm eye. 5. As air rises, it cools and condenses to cumulo-nimbus clouds and rain. 6. Cool air sinks into eye, so no clouds, rain & calmer.
• Ingredients for tropical storms

  • Ocean 27 degrees
  • Low wind shear
  • Coriolis effect (earth's spin)
• Climate change


  Could open up new areas to tropical storms e.g. SE Brazil 2004
• Studies have shown that the frequency of tropical storms will not change due to climate change