global hazards

• what happens in areas of high pressure

  cold air sinks
• what happens in areas of low pressure

  warm air rises
• what are tropical storms

  areas of low pressure
• where do tropical storms happen

  • typically between 5° and 15° north and south of the Equator
  • temperature of the surface of the ocean more than 26.5°C
  • ocean depth of at least 50-60 m
  • at least 500 kilometres away from the Equator so that the Coriolis effect can make the weather system rotate
• how do tropical storms form

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• how do tectonic plates move

  convection

  ridge push

  slab pull
• what are earthquakes

  violent shakings of the earths crust
• how are earthquakes caused

  when plates move past, towards and away from each other, friction causes the plates to get stuck then pressure builds then it is released then the earthquake occurs
• where does the earthquake start

  at the focus point
• what is a plate boundary

  where two or more tectonic plates meet
• what are volcanoes

  an opening in the earths crust, lava erupts
• where do volcanoes happen

  at constructive and destructive plate boundaries
• where do earthquakes happen

  at all plate boundaries
• collision

  plates move towards eachother
• destructive

  plates move towards each other or converge
• constructive

  plates move away from each other or diverge
• conservative

  plates slide past eachother
• what is weather

  the day-to-day condition of the atmosphere
• what is climate

  refers to the long-term patterns and averages of temperature
• what is the temperature in britain

  britain has a wild climate
• what is air pressure

  the total weight of the air in the atmosphere pushing down on the surface of the earth
• what is el nino

  a natural climate phase that brings warmer global temperatures and can increase the risk of extreme weather
• what is la nina

  When the sea surface temperature drops by around 3-5 degrees Celsius
• what is extreme weather

  when a weather event is significantly different from the average or

  usual weather pattern
• examples of extreme weather

  temperature

  wind

  precipitation
• what is drought

  a period of unusually dry weather when there is not enough rain
• countries most at risk from drought

  moldova

  ukraine

  bangledesh
• how has human activity made drought worse

  over abstraction of water

  deforestation has made areas drier
• what are composite volcanoes

  consist of alternating layers of ash and lava flows
• features of a composite volcano

  steep sides

  magma is vicious

  made up of layers of lava
• where are composite volcanoes found

  found on a destructive plate boundary
• what are shield volcanoes

   a type of volcano that erupts basalt lava and has a broad, flat shape
• features of a shield volcano

  produces low viscosity lava

  has no layers

  has less violent eruptions
• where are shield volcanoes found

  found on constructive plate boundaries
• what are hotspots

  a region deep within Earth’s mantle from which heat rises by convection and creates volcanoes
• how are hotspots formed


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