**2.3 Plate tectonic**

Plate tectonics is a scientific theory that describes the large-scale movement of seven large plates and the movements of many smaller plates from the Earth's lithosphere, since tectonic processes on Earth began between 3.3 and 3.5 billion years ago. The model is based on the concept of continental drift, an idea that developed during the early decades of the twentieth century. The theory of plate tectonics was accepted by the geological scientific community after sea floor propagation was validated in the late 1950s and early 1960s [5].

The lithosphere, the planet's rigid outermost layer, is divided into tectonic plates. The Earth's lithosphere consists of seven or eight main plates and many minor plates. When the plates encounter, their relative movement controls the type of boundary: convergent, divergent, or transformational. Earthquakes, volcanic activity, mountain building, and oceanic trench formation occur along these plate boundaries. The relative movement of the plates usually ranges from 0 to 100 mm per year [5].
