The Earth's crust is the outermost layer of the Earth, extending from the surface down to about 30 kilometers (18.6 miles) deep. It is composed of a variety of rocks, minerals, and sediments. The crust is divided into two types: continental crust and oceanic crust. Continental crust is thicker and less dense than oceanic crust, consisting mainly of granite rocks. It forms the continents and extends beneath the shallow seas surrounding them. Oceanic crust, on the other hand, is thinner and denser, primarily made up of basalt rocks. It underlies the ocean basins and is constantly being created at mid-ocean ridges and destroyed at subduction zones. The Earth's crust is a dynamic and ever-changing layer. It is divided into several tectonic plates that float on the semi-fluid asthenosphere beneath them. These plates are in constant motion due to the convective currents in the underlying mantle. The movement of these plates leads to various geological phenomena such as earthquakes, volcanic...