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  • Earth
    • Crust- very thin outer layer
    • Plate Tectonics
      • plate boundary- place where plates meet
        • Constructive
          • plates move apart
          • magma comes up and fills the gap causing volcanoes
          • magma can escape easily so it does not erupt with much force
          • Earthquakes are found and islands are made
        • destructive
          • continental and oceanic (more denser) plate meet.
          • oceanic plate sinks below the other and melts into hot liquid rock (magma)
          • volcanoes may erupt with lots of force, earthquakes will occur
        • Conservative
          • two plates slide past each other along a fault (weakness)
          • earthquakes occur
      • The surface is made up of plates that are moving very slowly, because of the convection currents in the mantle
    • Volcanoes
      • active volcano- erupted recently and is likely to erupt again
      • Dormant- has not erupted for many years
      • Extinct- not erupted for thousands or millions of years
      • Cross section of volcano
      • Ash volcano- formed from ash, steeped sided with large crater
      • Lava volcano- thick slow-flowing lava that hardens quickly forms steep sides .
      • Lava volcano- runny faster flowing lave moves and spreads over a larger area, forms gently sloping sides
      • opening or vent in earth's surface
      • Why people live in volcanic areas
        • fertile soil for farming
        • geothermal energy can be produced
        • tourist attraction
      • Volcanic Bombs- lumps of molten rock that solidify they fall
      • Predicition-
        • small earthquakes
        • smell
        • water level and temperature increase
        • volcano shape change
    • Earthquakes
      • happen along plate boundries
      • plates move past eachother
        • they become locked
          • friction causes pressure to build up. Suddenly pressure is released and they jolt into position. This cause vibrations
      • focus- point of which the rock moves
      • seismic waves start at focus
      • epicenter directly above focus on earth's surface
      • measured using richtor scale measures the magnitude of tremor. Size 6 is 10 times larger than 5 etc
      • predict- animals act strangely, small tremors
  • opening or vent in earth's surface


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