The three primary causes for tectonic plate movement are the convection of material in the mantle, gravity and the rotation of the planet. These forces cause each of the seven major plates and numerous other microplates to move independently of the others at a rate of a few centimeters per year.Know More
The most studied aspect of plate movement involves the large convection currents in the mantle. As energy is transferred throughout the molten levels of the mantle (asthenosphere), new material is pushed up towards the surface, moving the old rock out of the way. The emergence of this new land causes the plates to move where the material comes out.
The most easily recognizable example of this process occurs at the mid ocean ridges, where the plates on either side of the ridge are being pushed away from each other. The ridges where this new material emerges are higher in elevation than the surrounding areas, and gravity causes the older rock to fall down to the lower points, aiding in the movement of the plates.
According to About.com, the rotation of the Earth is also a contributor to the movement of the tectonic plates but is far less significant than either the convection of the mantle or the force of gravity.Learn more about Plate Tectonics
The Earth's crust is made up of a number of plates that sit on top of the mantle, which is made up of molten rock. The movement of these plates is called plate tectonics. Plate movement can, over time, cause mountains to form, volcanoes to erupt and earthquakes.Full Answer >
Earth has between 10 and 20 crustal plates, each moving at a different rate. The slowest is the Eurasian plate, which moves less than an inch per year, while the plate with fastest known movement is the Cocos plate, which grinds against the west coast of Central America at an estimated 8.55 inches per year.Full Answer >
Continental and oceanic are the two types of tectonic plates. Continental plates tend to be larger than oceanic and bear the majority of a continent's mass. Continental plates tend to be much thicker on average, but less dense.Full Answer >
The plate tectonics theory suggests that the outer shell of the Earth's surface is split into a few plates that move along the mantle, forming a hard shell, with pressure from mid-ocean ridges and subduction zones causing the shifting in the plates. Mid-ocean ridges are the gaps that lie between the plates, much like the seams on a basketball. Magma oozes through these ridges, creating new crust on the ocean floor and pushing the plates apart, while subduction zones sit at the meeting point between plates. One slides under the other, pulling the crust down as it goes.Full Answer >