More on plate tectonics from Infoplease:

• plate tectonics: meaning and definitions - plate tectonics: Definition and Pronunciation
• Earthquakes! - Learn about how often earthquakes occur, what causes them, the difference between intensity and magnitude, and about tsunamis.
• Continental Drift and Plate-Tectonics Theory - Find information about continental drift and plate-tectonics, along with other facts about world geography.
• Volcanoes of the World - Volcanoes of the World The Nature of Volcanoes Recent Volcanic Activity The Deadliest Volcanic ...
• PLATE TECTONICS - Scientists believe that the Earth’s outer crust is made up of about huge fragments, called tectonic plates, that fit together like a cracked eggshell.

See more Encyclopedia articles on: Geology and Oceanography