Continental Drift
What was the name of the supercontinent that existed 250 million years ago?
Pangaea
Name the thin outer layer of the Earth.
Crust
Where do convection currents occur?
In the mantle
Name the three types of plate boundaries.
Constructive, Destructive, Conservative
What is the name of the point where two plates meet?
A plate boundary
Who proposed the theory of continental drift in 1912?
Alfred Wegener
Which layer is made of molten and semi-molten rock (magma)?
Mantle
What causes magma to rise?
Heat from the core
At which boundary is new crust formed?
Constructive
Which type of plate is heavier: oceanic or continental?
Oceanic plate
The theory that continents were once joined together and have slowly moved apart over time.
What is continental drift?
What metals make up the outer core?
Nickel and iron
Why does magma sink again?
It cools, becomes denser, and sinks
What is subduction?
When an oceanic plate is forced under a continental plate
What is a large slab of the Earth’s crust called
A tectonic plate
Name the two landmasses Pangaea split into.
Laurasia and Gondwanaland
Which is hotter: the mantle or the inner core?
Inner core
What causes Movement of tectonic plates ?
convection currents
Which boundary causes earthquakes but not volcanoes?
Conservative
What is the name given to melted rock beneath the Earth’s surface after it has reached the surface?
Lava
Give one piece of evidence that continents were once joined.
Coastlines fit together (e.g. South America and Africa), fossils, rock similarities.
Give two differences between oceanic crust and continental crust.
Oceanic: thinner, denser, basalt.
→ Continental: thicker, less dense, granite.
Explain how convection currents move plates.
Heat from the core causes magma to rise. It cools and sinks, creating circular currents that drag plates apart, push them together, or slide them past each other.
Explain why volcanoes form at destructive boundaries.
The oceanic plate subducts, melts in the mantle, magma rises to the surface forming volcanoes.
What temperature does the inner core reach?
Up to 6,000°C.