Structure of the earth

• Earthquakes are caused by convection currents in the earths mantle
• Alfred Wegener suggested that all of the continents were once joined

  together in one supercontinent, called Pangaea. and that over millions of years they drifted apart.
• Wegener’s theory did not include any attempt to explain how the continents moved and it was dismissed by scientists of the time.
• This idea of ‘continental drift’ is based on the following observations:

  
  

  • jigsaw-like fit of the edges of continents

  • similar rocks of the same age found on different continents

  • similar plant and animal fossils found on opposite sides of huge oceans.
• The surface of the Earth (Crust) is divided into a number of different fragments named, tectonic plates.
• The movement of the tectonic plates causes the

  continents to move.
• Destructive plate boundaries (continental v continental) move towards each other by folding
• Destructive plate boundaries (continental v continental) create fold mountains and earthquakes
• examples of destructive plate boundaries (continental v continental) are the Himalayan mountains
• Destructive plate boundaries (continental v oceanic) move towards each other and the denser plate is subducted
• Destructive plate boundaries (continental v oceanic) create volcanoes and earthquakes
• an example of destructive plate boundaries (continental v oceanic) is the Hawaiian islands
• What type of plate boundaries create fold mountains and earthquakes?

  Destructive
• Constructive plate boundaries move apart from each other
• Constructive plate boundaries create Ridges, volcanoes and earthquakes
• An example of a constructive plate boundary is the north American & Eurasian plates
• As constructive plate boundaries move apart, magma rises into the gap which cools and solidifies to form new igneous rocks
• Conservative plate boundaries move side by side
• What plate boundaries move side by side?

  Conservative
• What plate boundary is the north American & Eurasian plates?

  Constructive
• What plate boundaries create ridges, volcanoes & earthquakes?

  Constructive
• What plate boundaries move apart from each other?

  Constructive
• The Hawaiian islands is an example of what plate boundary?

  Destructive (continental v oceanic)
• Volcanoes and earthquakes are made by what plate boundaries?

  Destructive (continental v oceanic)
• What plate boundaries move towards each other, where the denser plate is subducted?

  Destructive (continental v oceanic)
• What plate boundaries move together by folding?

  Destructive (continental v continental)
• What plate boundaries create fold mountains and earthquakes?

  Destructive (continental v continental)
• What type of plate boundaries are the Himalayan mountains?

  Destructive (continental v continental)
• Conservative plate boundaries create fault lines and earthquakes
• What plate boundaries create fault lines and earthquakes?

  Conservative
• An example of a conservative plate boundary is the San andreas fault
• The San andreas fault is an example of what plate boundary?

  Conservative