geography paper 1

• what are hadley cells

  hadley cells are the largest atmospheric circulation cells causing rain at around 30 degrees north and south of equator
• arid 


  dry area with little to no rain
• ITCZ


  a band of low pressure around the earth which is near the equator
• volcanic activity causing climate change

  ash is released into the atmosphere which blocks out light from the sun reducing earths temperature
• asteroid impacts causing natural climate change

  the impact blasts ash and dust into the atmosphere blocking sunlight
• solar activity causing climate change

  the suns dark patches are sun spots which are intense solar storms. more spots means more solar energy is being fired out towards the earth. in a period of 11 years the amount of sun spots vary.
• milankovitch cycles - natural climate change

  -earths orbit can change from circular to oval and back again

  -the earth can wobble on its axis

  -the tilt of the earths axis moves back and forth
• what is a tropical cyclone

  huge storms where wind speeds are high. they form 5-15 degrees north and south of the equator
• 2 factors that cause tropical cyclone

  ocean temperatures being above 26.5 degrees

  the spinning ( Coriolis ) effect on the earths rotation - high
• hazards of tropical cyclones

  - coastal floodings

  - storm surges

  - landslides

  - strong winds

  - intense rainfall
• cyclone preparation ( 3 )

  - forecasting

  - warning systems

  - storm surge defences

  - responses
• Eye of the storm

  calm clear sky
• order of earths atmosphere

  inner core,

  outer core,

  mantle,

  crust
• conservative plates

  two plates sliding past eachother causing friction
• divergent plates


  two plates move apart and magma is forced to the surface
• convergent plates


  two plates moving towards eachother where the oceanic plate is submerged due to the higher density compared to the continential plate
• collision plate


  two plates coming together forcing one to push over the other
• collision causes : 


  earthquakes

  rare volcanic eruptions
• convergent causes


  earthquakes

  large volcanic eruptions

  tsunamis
• divergent cause 


  small earthquakes

  shield volcanoes
• conservative cause 


  earthquakes

  small tremors
• saffir simpson scale

  measures wind hazards for a hurricane 1-5
• richter scale

  measures the stregnth of earthquakes - 1-9
• tropical cyclones physical hazards


  - high winds -250km/hour

  - intense rainfall

  - storm surges

  - coastal flooding

  - landslides - saturate soil turning it into slope

  - physical vulnerability - areas of high relief more at risk

  - social vulnerability - effects poorer countries, limited supply of clean water, social inequalities cause more problems, more people die

  - economic vulnerability - more developed areas have better tech for prediction and modelling data
• what is a megacity

  city with 10 mil + people
• cycle of urbanisation 


  cycle

  1. urbanisation - people urbanise to cities for jobs and services
  2. suburbanisation - people move to suburbs as easier transport and less violence
  3. Counter Urbanisation - citizens move away from cities due to pollution, high rent, overcrowding
  4. re-urbanisation - people move back into city as it improves
• urban land uses


  commercial - expensive land, most accessible in the city

  residential - houses

  industrial - factories