Book 5, Question 60
Slow Motion Puzzle! Why Do Earth's Plates Move?
Earth's outer shell is made of huge plates that fit together a bit like puzzle pieces. They move very slowly, about as fast as your fingernails grow. Heat deep inside Earth helps drive the movement.
From the book
Page from A Million Whys Book 5
More fun facts
- A plate is a huge, stiff slab of solid rock.
- The word tectonics comes from a Greek word meaning to build.
- Earth has a few handfuls of major plates and dozens of smaller ones.
- Six major plates are named after the continents riding on them, like the North American and African plates.
- Heat from deep inside Earth makes the plates move, sometimes toward each other and sometimes apart.
- Plates move about one to two inches a year.
- Where an ocean plate dives under another plate, it is called subduction.
Sources: NOAA, National Geographic, NOAA Ocean Service
Questions kids ask
Can I feel the plates moving?
Not usually. They move only an inch or two a year, but over millions of years that adds up.