The epicenter of an earthquake is the point on the surface of the Earth directly above the point in the crust where a seismic rupture occurs. This origin point within the crust is called the hypocenter or focus.
Though the epicenter is central to the area of effect of an earthquake, it is not necessarily where the strongest shaking is experienced. Historically, the epicenter was believed to be so, but modern seismic measuring equipment has shown in several instances that shaking is more severe in areas several miles away. From this, a debate has emerged over whether earthquakes should be named after the location of their epicenters or the communities they primarily effect.