Natural Hazards

  • Created by: Morsey02
  • Created on: 02-11-18 16:36
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  • Natural Hazards
    • A natural event that threatens people or has the potential to cause damage, destruction and death.
      • People live near natural hazards - better nutrients for crops, cant move, trade routes.
    • Plate Tectonics. The African plate moves away from the south American plate. The pacific plate is moving away from the nazca plate
      • Convection currents hep transfer heat from the earths core - where magma is created.
      • Conservative plate boundary - Plates go past each other but in opposite directions, friction is overcome and the plates slip causing an Equake
      • Subduction - the oceanic plate is denser than the continental so it is forced under the continental when they move. Cause Equakes due to the magma rising
      • Constructive - 2 plates moving apart in opposite directions causing cracks overtime they create undersea mountains.
      • Collisional - 2 similar plates are forced together, they crumble and fold upwards creating mountains.
    • Layers of the earth
      • Inner Core - The hottest point, it is 55o degrees and made from iron + nickel. It is a solid
      • Outer Core - Has extreme  tempretures, contains iron + nickel, contains the magnetic field. It is a liquid.
      • The Crust - Layer we live on, cracked into plates. It is a solid.
      • Mantle - Below the crust, it moves very slow due to convection currents which make the plates move. It is a solid
    • Equakes
      • Pyroclastic flow - Hot gases, ash, pumice and lava above 800 degrees Lahars - Volcanic debris saturated with water .
        • Predicting equakes -  Use radon detectors which are placed in the soil. Animals + fish act unusual.
      • Tropical Storms
        • Warm air from the storm & warm ocean higher than 27 degrees mix creating low pressure. Trade win ds in opposite directions make it spin.
          • Air keeps rising and the pressure starts to decrease at higher altitudes.  Air rises faster and faster to try & fill low pressure drawing more warm air from sea and sucking cooler air down
            • As the storm travels over the ocean it collects warm moist air, the wind speed increases along with the air, The eye has low winds surrounded by a sinning vortex of high winds + heavy rainstorms.
    • Global air circulation
      • Air that is sinking towards the ground surface forms areas of high pressure, Winds on the ground move outwards from this area.
      • Air that is rising from the ground surface forms area of low pressure on the ground.
      • Winds on the ground are distorted by earths rotation. They curve from areas of low to high pressure.

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