Global hazards

• Boscastle case study physical causes

  • Rain increased rivers 2.15 metres in 1hour
• Boscastle case study human causes

  • Vegetation under bridge acted as a damn
  • Pattern of streets made it easily flood able
  • Insufficient sewer systems
  • Boscastle built at metting point of 3 rivers
• Boscastle case study social consequences

  • 84 cars wrecked
  • 58 properties flooded
  • 1000 people effected
• Boscastle case study economic consequences

  • Boscastle is 90% tourists so B+Bs shut losing money
  • Infrastructure damage cost £2 billion
• Boscastle case study environmental consequences

  • Trees destroyed
  • Ocean polluted by car fuel
• Boscastle case study short term responses

  • 7 helicopters sent out
  • 120 people rescued
  • Sand bags to absorb water
  • Locals provided accommodation
• Boscastle cast study long term responses

  • Flood culvert installed to make river flow better
• Drought

  Definition less water than usual for area

  Causes high pressure

  What happens high temperature causes more evaporation and fewer clouds

  Where deserts

  How has it changed since 1940 severity has increased due to changing rainfall patterns
• What happens at polar cell

  Air cools and sinks
• What happens between polar and cells

  Polar and warm air mixes and rises
• What happens between ferrel and Hadley cell

  Cool air sinks making it warmer
• What happens at Hadley cells

  Warms air rises and cools to make clouds
• Polar insolation

  Sun heat spreads out
• Equatorial insolation

  Sun heat is concentrated
• Conservative plate boundary

  2 plates slide against eachother creating earthquakes
• Constructive plate boundary

  Plates move away and magma rises forming shield volcano
• Destructive plate boundary

  Continental crust forces oceanic crust to subduction allowing magma to rise to form a composite volcano
• Collision plate boundary

  2 plates push together to create mountains and earthquakes
• Shield volcano

  • Sloping sides
  • Low viscosity
  • Frequent eruptions
  • Not explosive
• Composite volcano

  • Low frequency
  • High viscosity
  • Very explosive
  • Crates side vent
  • Pyroclastic flow
• Shallow focus earthquake 


  Depth 0-70km

  Frequency common

  Magnitude 1-5 richeter scale

  Seismic waves radiate horizontally

  Damage widespread
• Deep focus earthquake

  • Depth 70-700km
  • Frequency rare
  • Magnitude 6-8 richet scale
  • Seismic waves radiate vertical
  • Damage localised
• Affects of tectonic hazards AC

  • Low death rate
  • High economic cost
  • People receive support quickly
• Affects of tectonic hazards LIDC

  • High death rate
  • High damage
  • Less prepared
  • Rely on international aid for support
• Iceland volcano case study causes

  • Earthquakes increasing
  • Fissure ripped open after chamber filled up
  • Magma stored under 200m thick of glacier ice
• Iceland volcano social consequences

  • Tourists move to hotels
  • Houses destroyed
  • Lack of food
• Iceland volcano environmental consequences

  • 20 farms destroyed
  • Health risks due to ash
  • Ice melting increased
• Iceland volcano economic consequences

  • International flights cancelled so lost money
  • £3.5 million lost to trade
  • Lost £1.87 million of oil which now increases petrol prices
• Iceland volcano short term responses

  • People use trains and ferries
  • Warning messages sent on tv
• Iceland volcano long term response

  • Health problems from ash
  • Introduces to thermal cameras for future
• Big dry case study causes

  • El nino trade winds made it warm and dry
  • Country overpopulated
  • Murray River hime to 2 million people
• Bg dry case study social consequences

  • 173 deaths
  • 10000 people unemployed
  • 2000 homes destroyed
• Big dry case study economic consequences

  • Food prices increased
  • Water shortages
• Big dry case study environmental consequences

  • Huge dust storm
  • Crops irrigated
  • Lower rainfall
• Big dry case study short term responses

  • Farmers had to sell cattle
  • People move to cities
  • Recycled water
• Big dry case study long term response

  • Efficient irrigation systems installed
  • Desalination plants built