 Such information in turn is helpful in studying the motions of continents and ocean floors in the process of plate tectonics.The magnetosphere is the region above the ionosphere that is defined by the extent of the Earth's magnetic field in space.It extends several tens of thousands of kilometers into space, protecting the Earth from the charged particles of the solar wind and cosmic rays that would otherwise strip away the upper atmosphere, including the ozone layer that protects the Earth from harmful ultraviolet radiation.