An interplate earthquake is an earthquake that occurs at the boundary between two tectonic plates. If one plate is trying to move past the other, they will be locked until sufficient stress builds up to cause the plates to slip relative to each other. The slipping process creates an earthquake with land deformations and resulting seismic waves which travel through the Earth and along the Earth's surface. Relative plate motion can be lateral as along a transform fault boundary or vertical if along a convergent subduction boundary or a rift at a divergent boundary. At a subduction boundary the motion is due to one plate slipping beneath the other plate resulting in an interplate thrust or megathrust earthquake. Some areas of the world that are particularly prone to such events include the west coast of North America (especially California and Alaska), the northeastern Mediterranean region (Greece, Italy, and Turkey in particular), Iran, New Zealand, Indonesia, Japan, and parts of China. The frequency (how often) of these large events may be controlled by the Gap Theory and Characteristic earthquakes.
