The answer is "Energy built up when plates try to get past each other is released when plates break free."
The mechanisms and procedures included when earthquakes happen are amazingly mind boggling. Anyway a portion of the qualities of quakes can be clarified by utilizing a basic elastic rebound theory.
The elastic rebound theory is a clarification for how energy is spread amid quakes. As rocks on opposite sides of a blame are subjected to power and move, they collect vitality and gradually misshape until their internal quality is surpassed.