Tectonics

• Types of tectonic events:

  earthquakes

  volcanic eruptions

  landslides
• Earthquake - sudden release of energy from the earth's crust, caused by movement along fault lines.
• Landslide is a rapid downward movement of rock, debris, or soil under the influence of gravity.
• Volcanoes are formed when magma rises to the surface through fissures or vents on the Earth’s surface.
• Types of tectonic plate Margins:

  • Conservative
  • Collision
  • Constructive
  • Destructive
• At constructive margins, the oceanic plate is pushed under the continental plate.
• At conservative margins the two plates are moving past each other at right angles to each other
• Japan

  Deaths - 18000

  Cost - 235 billion

  Magnitude - 9.1
• Nepal

  Deaths - 9 000

  Cost - 5 billion

  Magnitude - 7.9
• Constructive: plates move apart
• Destructive: Plates move towards each other
• Collision: plates move together
• Conservative: plates move alongside each other at different speeds
• Volcanoes are formed at destructive plate margins
• Destructive plate margin


  plats move together

  • oceanic plate meets a continental plate
  • oceanic depends under the continental as it is heavier (zone of subduction)
  • as it descends it starts to melt, this forms magma
  • Magma rises through gaps in the continental plate (volcano Forms)
• constructive plate margin


  Plates move apart

  • pulled apart by convection currents in the soft rock beneath
  • liquid rock and magma rise between, forming volcanoes in the ocean floor
  • magma hardens into basalt (ocean floor rises)
• Collision plate margin


  Plates move together

  • two plates of similar densities
  • material between them rises up (forms fold mountains)
• Conservative plate margin


  Plates move along side each other at different speeds

  • can move at different speeds on different directions
  • earthquakes
• Nepal


  House made of mud - more susceptible to damage
• Japan

  More advanced houses - less susceptible to damage
• Nepal


  Low income country
• Japan

  high income country