Themes > Science > Earth Sciences > Geology > Earth > The Story Of Plate Tectonics > Plate Tectonics > Putting the pieces together

The Earth is made up of a dozen or so major plates and several minor plates. Tectonic plates are constantly on the move. The fastest plate races along at 15 centimeters (6 inches) per year while the slowest plates crawl at less than 2.5 centimeters (1 inch) per year.

Map showing locations of the Earth’s plates

You'll notice that most plates are part continental and part oceanic. Take the North American plate, for example. Its western half is dominated by the North American continent, but its eastern half forms part of the Atlantic Ocean basin. In comparison, the Pacific plate is essentially all oceanic.


Information provided by: W. Jacquelyne Kious and Robert I. Tilling
http://geology.wr.usgs.gov