USGS Geology in the Parks

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


Geology in the National Parks home \| U.S. Department of the Interior \| U.S. Geological Survey Privacy statement / General Disclaimer USGS Western Earth Surfaces Processes Team Webmaster http://geology.wr.usgs.gov/docs/usgsnps/index.html This page was last updated on 01/13/04