Earthquake is the earth, is the vibration of the earth's surface. Vibration of the earth's surface caused by many reasons, can be man-made causes, such as explosions, fire, mechanical vibration, etc.; the same can also be natural causes, such as tectonic earthquakes, volcanic earthquakes, collapse and earthquake.
According to the different causes of earthquakes, we can be divided into five seismic:
1. Tectonic earthquakes: tectonic earthquake because it is underground rock by the role of stress, when stress suffered too much, can not afford to rock occurs when a sudden, quick break or dislocation, fracture or dislocation when the rock will inspire a kind of spread to the surrounding land seismic waves, the local shock wave reached the surface, they will lead to ground vibration. 85% -90%, the world's earthquakes, and all major disasters caused by earthquakes are tectonic earthquakes.
2. Volcanic earthquakes: earthquakes caused by volcanic eruptions since.
3. Reservoir Earthquake: As the reservoir water storage, water distribution reservoir induced earthquake.
4. The fall of the earthquake: Since the fall of ground caused by earthquakes.
5. Artificial earthquake: As the nuclear explosions, fire and other human activities caused by the earthquake
Most earthquakes occur in the most rigid part of the Earth - the edge of the crust and upper mantle rocks inside. Where the role of rock under stress rupture. Became the source of this rupture, shock from here.