A force source of tectonic movement-A secondary mass center restoring force

The earth system discussed in this paper is composed of two secondary particle systems:a water body and a base body. The base body shows different behaviours under the actions of long term and short term effects of its rheologic character and viscoelasticity. The short term effects result in a secondary particle system to deviate from its original position, and produce a secondary mass center restoring force directly proportional to the deviating distance. The long term effects result in the earth's material producing a secondary mass center restoring motion under the action of the secondary mass center restoring force.