Quiz on Earth's Structure and Plate Tectonics

How old do scientists believe the Earth is?

• 7 billion years

• 6 billion years

• 5 billion years

• 4 billion years

What is the outer layer of the Earth called?

• Core

• Mantle

• Crust

• Inner Core

What is the average depth of the Earth's crust?

• 10 km

• 20 km

• 30 km

• 40 km

What is the main component of the Earth's mantle?

• Nickel

• Iron

• Silicates

• Magma

What is the theory that explains the movement of the Earth's plates?

• Plate tectonics

• Sea-floor spreading

• Convection currents

• Continental drift

What happens at divergent plate boundaries?

• Plates slide past each other

• Plates sink

• Plates move apart

• Plates collide

What is formed when two continental plates collide?

• Mid-ocean ridge

• Ocean trench

• Volcano

• Fold mountains

What is a subduction zone?

• Where plates move apart

• Where one plate is forced under another

• Where plates slide past each other

• Where new crust is formed

What did Alfred Wegener propose about the continents?

• They are made of different materials

• They were once joined together

• They are fixed in place

• They float on water

What is the name of the super-continent that existed millions of years ago?

• Atlantis

• Gondwanaland

• Laurasia

• Pangaea