1. Natural disasters Earthquake

2. An earthquake is ground shaking produced by the collision of tectonic plates and the release of energy in the course of a sudden reorganization of the crust material to overcome the state of mechanical equilibrium. Most important and frequently occur when the stored elastic potential energy released in the gradual deformation of rocks adjacent to an active fault plane, but can also occur for other reasons, for example about volcanic processes, by collapse of karst cavities or landslides.