Plate Tectonics is a set of related concepts that describe how the Earth works. Plate tectonics explains what happens when two continents run into each other, how and why parts of the Earth's surface are ripping apart, and why volcanoes and earthquakes occur where they do. The rigid outer "shell" of the Earth is broken into a number of pieces -- these are the plates. Due to heat generated deep within the Earth's interior these plates are in motion. They move across the surface of the Earth, and as they do, they bump and grind past each other. Bumping plates generate earthquakes. Plates that get pushed under one another create volcanoes. Try the activities on the next few pages to explore what else plates can do!

Clockwise from the top right, photos courtesy of the USGS, Alexandra Moore, and NASA.

Discovery Topics > Plate Tectonics <