Causes of Plate Tectonics
Scientists suggest that the plates move by the same basic process that occurs when you are cooking soup. The soup you cook (in a pan on the stove) contains currents caused by an unequal distribution of heat in the pan. The hotter soup is pushed upward by the cooler soup. When the hotter soup reaches the surface it begins to cool again. The soup in the bottom of the pan is now warmer so the cooler soup then forces the warmer soup back upward. This cycle repeats. This cycle is heating, rising, cooling, and sinking. This is known as convection current. A version of this process in the mantle is known to be the force behind the plate tectonics.