Editing Earthquake (section)

== Terminology ==
An earthquake is the shaking of the surface of [[Earth]] resulting from a sudden release of energy in the [[lithosphere]] that creates [[seismic wave]]s. Earthquakes may also be referred to as ''quakes'', ''tremors'', or ''temblors''. The word ''tremor'' is also used for [[Episodic tremor and slip|non-earthquake seismic rumbling]].

In its most general sense, an ''earthquake'' is any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by the rupture of geological [[Fault (geology)|faults]] but also by other events such as volcanic activity, landslides, mine blasts, [[fracking]] and [[Underground nuclear testing|nuclear tests]]. An earthquake's point of initial rupture is called its [[hypocenter]] or focus. The [[epicenter]] is the point at ground level directly above the hypocenter.

The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The [[seismicity]] at a particular location in the Earth is the average rate of seismic energy release per unit volume.