The Online Library of Knowledge


What are tectonic plates?

Tectonic plate edges shown in redTectonic plate edges shown in redThe Earth’s surface is like a ball-shaped jigsaw puzzle. It is made up of about 15 giant pieces, called tectonic plates. These plates are always shifting about—but only very gradually. Some plates are moving apart, others are pushing together. In some places, the edge of one plate slides down below another. In others, two plates slide past each other, moving in opposite directions. All this pushing, sliding or bumping at the edges of the plates causes earthquakes.

Africa and South America drifting apartAfrica and South America drifting apart

Continental drift

Each plate carries a piece of continent or a piece of the ocean floor, or both. The plates float like giant rafts on top of a molten layer of the mantle. In this way, the continents gradually move to new positions around the globe. This is called continental drift. Over hundreds of millions of years, the map of the world has changed completely.


The Atlantic Ocean gets wider by about the width of your thumb every year, pushing North and South America away from Europe and Africa.

© 2020 Q-files Ltd. All rights reserved. Switch to Mobile