Journey to the centre of the earth Flashcards
What is plate tectonics?
The theory that Earth’s crust is made of moving plates.
What causes plates to move?
Convection currents in the mantle.
What are the three types of plate boundaries?
Convergent (collide), Divergent (move apart), Transform (slide past).
What happens at each boundary?
Convergent → Mountains or volcanoes
Divergent → New crust forms (mid-ocean ridges)
Transform → Earthquakes
What is the Ring of Fire?
A zone around the Pacific Ocean with many volcanoes and earthquakes.
What are the four layers of the Earth?
Crust, Mantle, Outer Core (liquid), Inner Core (solid).
What is the thickest layer?
The mantle.
What is the thinnest layer?
The crust.
What is the core made of?
Iron and nickel.
What is the lithosphere?
The solid outer layer (crust + upper mantle
What is the asthenosphere?
A semi-molten layer in the mantle where plates move.
