geological hazards

• a natural hazard is a natural event that caused harm to people and property
• factors that effect hazard risk:

  • deforestation
  • urbanisation
  • level of development ( better infastructure )
  • climate change
• how plates move (theories)

  • convection currents
  • slab pull and ridge push - when gravity drags the plates into the mantle due to its weight
• oceanic plates

  • thinner
  • much denser
• continental plates

  • thicker
  • less dense
• constructive plate margins

  • plates move away from eachother
  • magma rises , cools and solidifies
  • sheild volcanoes form (gentle slopes + wide base )
  • small earthquakes
• destructive plate margins

  • oceanic and continental plates move towards eachother
  • oceanic plate subducts and melts
  • where a vent exists, melted crust erupts
  • volcanic eruptions are violent
  • lava is thick and viscous
  • steep sided volcanoes formed
  • fold mountains form
  • earthquakes happen because of pressure build up
• conservative plate margins

  • plates move alongside eachother
  • friction causes them to get stuck
  • fault lines are common
  • very violent earthquakes
• pyroclastic flow are deadly flows of toxic gases and hot rocks
• focus is where the earthquake takes place underground
• epicentre is on the surface right above the focus
• monitering and predictions

  • using scientific equipment to detect signs
  • difficult to preedict where and when an earthquake will happen
  • satellites
  • thermal heat sensors
  • seismologists read seismographs
  • observing volcanoes
• protection

  • builing strong infastructure using shear walls and shock absorbers
• planning and protection

  • exclusion zones
  • evacuation plans