NPS home USGS home USGS/NPS banner

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.

On to: The action is at the edges

| Into Earth | Putting the pieces together | Action at the edges |
| Earth through time | Detailed version: This Dynamic Earth |
horizontal bar
| USGS Geology in the Parks home | NPS Park Geology Tour home |

This site is a cooperative endeavor of the
US Geological Survey Western Earth Surface Processes Team
and the National Park Service.

Please share your comments and suggestions with us!
This page was last updated on 11/22/99