Tectonic Plates
Understand that Earth's crust is broken into large pieces called tectonic plates that float on hotter, softer rock beneath and move very slowly — a few centimetres per year
What a learner can do afterwards
- Describe Earth's crust as broken into large plates
- Explain that the plates float on hotter, partially melted rock underneath
- State that plates move very slowly, typically a few centimetres per year
The lesson
You already know Earth has layers, with a hard rocky crust as the outside shell. That crust is not one solid piece. It is cracked into giant pieces called tectonic plates, fitted together like a puzzle wrapped around the whole planet.
Think about the Ring of Fire you already learned about. Many earthquakes and volcanoes happen right where two tectonic plates meet and grind against each other. The plates move too slowly to see, but their edges build up huge amounts of force over time.
A handy way to picture the speed: tectonic plates move about as fast as your fingernails grow. You cannot see either one moving, but wait long enough and the change is easy to spot.
Earth's crust is broken into huge tectonic plates that float on hotter, softer rock and creep only a few centimetres each year.
Watch it
Where it sits
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.