Plate tectonics is the unifying theory of geology. Plate tectonics theory explains why:

• Earth’s geography has changed through time and continues to change today.
• some places are prone to earthquakes while others are not.
• certain regions may have deadly, mild, or no volcanic eruptions.
• mountain ranges are located where they are.

Plate tectonic motions affect Earth’s rock cycle, climate, and the evolution of life.