Tectonic Hazards

• The Earth's crust is divided into slabs called tectonic plates that float on the mantle.
• Oceanic crust and continental crust are the two types of plate.
• Continental crust is thicker than oceanic crust but less dense.
• The plates are moving because of convection currents in the mantle.
• The places where plates meet are called plate boundaries or margins.
• The three types of plate boundary are destructive, conservative and constructive.
• Destructive Plate Boundary:

  • Two plates move towards each other
  • An oceanic plate meets a continental plate
  • Oceanic subducts because it is denser
  • Destroyed in the mantle forming gas-rich magma
  • Volcanoes can occur due to build up in pressures
  • Two continental - crust pushed upwards to form fold mountains
• Constructive Boundary:

  • Two plates moving away from each other
  • Magma rises to fill the gap
  • The magma cools to creating new crust
• Conservative Boundary:

  • Two plates move sideways in the opposite direction