When the two plates separate magma fills the void and a volcano is produced. These chains of volcanic mountains are the longest mountain chain in the world. Volcanoes can also form at a hot spot. Earthquakes occur because the Earth's plate are in motion. The plates do not move smoothly and evenly.
Great stresses build up along the plate boundaries.
When a plate moves suddenly a great amount of energy is released in the form of wave energy. These waves are what cause the damage from an earthquake. Along plate boundaries. The main earthquake zones are the Circum-Pacific belt that stretches around the rim of the Pacific Ocean and the Alpide Belt in Europe and Asia. Volcanoes grow from their eruptions.