Tectonics

• Constructive margin

  Firstly plates move APART through ridge push

  Secondly hot magma rises as plates SEPARATE

  Thirdly magma cools and gardens forming new crust and a ridge

  Finally  gentle volcanic activity
• Destructive margin

  Firstly dense oceanic sinks under continental plate through slab pull

  Secondly plates jam pressure is released, earthquake occur

  Thirdly oceanic plate melts

  Finally magma rises through crack, and violent volcanic eruptions occur
• Constructive margin

  Firstly, one plate is moving quicker than the other

  Secondly plates jam due to friction

  Thirdly pressure builds then is released

  Finally violet earthquakes occur through seismic energy