Earth structure

• What are the different layers of the Earth?

  Crust, mantle, outer core, inner core
• What is the outer layer of the Earth called?

  The crust
• What is the composition of the inner core?

  Iron and nickel
• What is the temperature of the inner core?

  Up to 5,500°C
• What state of matter is the outer core?

  Liquid
• What is the thickness of the mantle?

  Approximately 2,900 km
• What is the mantle made up of?

  Semi-molten rock called magma
• What is the theory of plate tectonics?

  Movement of the Earth's crust and tectonic plates
• How thick is the Earth's crust?

  0 - 60 km thick
• What are the two types of crust?

  Continental and oceanic
• What are tectonic plates?

  Broken sections of the Earth's crust
• What was once believed to cause the movement of tectonic plates?

  Convection currents in the mantle
• What are the mechanisms believed to move tectonic plates?

  Slab pull and ridge push
• What is ridge push?

  New crust rises at divergent margins
• What happens to the older seafloor at divergent plate margins?

  It slides away, moving the seafloor apart
• How do convection currents relate to tectonic plate movement?

  Plates drive convection instead of vice versa
• What is slab pull?

  Older plates sink at subduction zones
• What occurs when older sections of tectonic plates sink?

  Newer sections are pulled along behind
• What is the term for the movement of the plates and activity inside the Earth?

  The theory of plate tectonics