The lithosphere of the Earth moves as plates on the ductile mantle. This shell is divided up into sections called plates . The surface of the earth is divided into 12 large plates, along with several smaller ones. This map shows the plates that make up the Earth's crust. Earthquakes occur due to movement of tectonic plates, which results in breaking of rock.
Strain accumulates in the Earth along faults by the movement of tectonic plates.
When plates collide, the earthquake is the result from the collision. The boundries where two plates collide, and one is pushed down under the other is called a subduction zone . Most all very large earthquake occur within subduction zones. When two plates slide past each other, this is a transform boundry . Earthquakes also occur at this type of fault.