THE DYNAMIC EARTH

THE DYNAMIC EARTH
The earth's crust is made up of eight major (and several minor) rigid continental and oceanic tectonic plates ,which fit closely together .the positions of the plates are not static . They are constantly moving relatively to one other. The type of movement between plates affect in the way in which they are alter the structure of earth . The oldest parts of the planets ,known as shields ,are the most stable parts of the earth and little tectonic activity occurs here .