One of the most dramatic examples of crustal deformation. The energy radiates in the form of seismic waves in all directions from the fault rupture. The epicenter is the point on the earth's surface directly above the focus.
Most earthquake faults occur along plate boundaries.
First formulated by H.F. Reid after 1906 San Francisco earthquake. The deformed rock snaps back to a more relaxed condition with a permanent displacement occurring across the fault. The cycle starts again Sometimes referred to as stick-slip behavior Relative displacements in a single earthquake can be as much as several meters. Mainshock is followed by many aftershocks and occasionally preceded by up to a few foreshocks. Aftershocks probably occur because stresses have been increased by the mainshock on small secondary faults at the edges of the rupture.