The primary cause of an earthquake is faults on the crust of the earth. The cracks or sudden slips of the land are known as faults or fault planes. The point of origin of the earthquake is inside the earth and is known as the hypocenter. Maximum destruction is caused at the epicenter, the surface above the hypocenter. When there are sudden movements in the various layers of the earth, crust or mantle, concentric waves are produced. These waves are known as seismic waves