Why do Lithospheric Plates Move Constantly?
Scientists believe that lithospheric plates don’t move on their own. There are internal forces that are responsible in the movement of plates on the earth’s crust. Since the earth rotates in its axis, the mantle is believed to be constantly moving as well. Scientists know that the lithospheric plates move on its own pace and even with the technology that we have today, there are no means for us to know the reason and the speed of its movement.
The lithosphere includes the crust and the earth’s mantle. It is the hard and rigid part of the earth. It is composed of different tectonic plates that move all the time. The first ever recorded evidence of the movement of the lithospheric plates came from the discovery of the effects of magnetic field in rocks of differing ages.
The lithosphere is also considered as a protective layer that surrounds the earth’s mantle. There are two types of lithosphere, the oceanic and the continental lithosphere. The oceanic lithosphere exists in the ocean basins of the earth. The continental lithosphere on the other hand is associated with the continental crust. The thickness of the lithosphere is estimated roughly around 40-150m km. The only difference that separates the layers of the earth is the chemical and mineral composition of each layer.
There are three known types of boundaries between lithospheric plates. These types of boundaries are the divergent boundaries, the convergent boundaries and the subduction. The divergent boundary is where the lithospheric plates move and the crust is created. The convergent boundary is called the ‘collision zones, where the crust is destroyed. Finally subduction, on where the destroyed crust rises up to the surface to form mountains, and even volcanoes. The movements of the plates are probably the most destructive and creative forces, responsible for the formation of our planet.