Washington University geophysicist Anne M. Hofmeister have proposed that imbalanced forces and torques in the Earth-moon-sun system drive circulation of the whole mantle.
The new study provided an alternative to the hypothesis of the movement of tectonic plates is connected to convection currents in the Earth’s mantle. Convection involves buoyant rise of heated fluids. Scientists said it does not apply to solid rocks. Scientists said that force moves large objects.
Earth’s internal workings are modelled as dissipating heat which was generated by internal radioactivity. From the leftover energy created during collisions at the time our planet formed. Mantle convection proponents recognize the amount of internal heat-energy is insufficient to drive large-scale tectonics. There are other problems of using convection to explain observed plate motions.
Earth’s plates have shifted as the sun exerts strong gravitational pull on the moon. It has caused the moon’s orbit around Earth to become elongated.
The position of the barycentre which is the centre of mass between the orbiting bodies of the Earth and the moon, has moved closer to Earth’s surface. It is now oscillating 600 km per month relative to the gyrocenter. This sets up internal stresses.
Daily spin flattens the Earth from a perfect spherical shape. This contributes to this brittle failure of the lithosphere. These two stresses form the mosaic of plates which is observed in the outer shell. The variety of plate motions comes with time from the changes in size and direction of the imbalanced gravitational forces.
The study had a comparison of rocky planets. It shows that the presence and longevity of volcanism and tectonism depend on the particular combination of moon size and proximity to the sun.
Scientists said, Earth is the only rocky planet with all the factors needed for tectonics plate.
