Researchers from the University of Sydney discovered the reason for the movement of the Earth's tectonic plates across its surface.

Patrice Rey, one of the researchers, said that movements of tectonic plates only occurs on Earth and doesn't happen on other planets in the solar system.

He said that geological records show that the Earth's crust was immobile until it moved three billion years ago.

Like Us on Facebook

Rey and his colleagues believe that the spread of early continents caused the movements of tectonic plates but the movementseventually became a self-sustaining process.

Researchers said that there are eight major tectonic plates movement that occurred above the Earth's mantle at rates up to 150 millimeters every year.

Plate tectonics occur when plates were dragged into the mantle and moves away from each other. It depends on the relationship of temperature and rock density.

According to researchers, three to four billion years ago Earth's interior was hotter and volcanoes tend to be very active.

These cause tectonic plates to become cold and dense enough to spontaneously sank, they added.

Rey said that the driving engine for the movement of plate tectonics cannot exist therefore creating thick and early continents that erupted in the middle of the immobile plates.

He also said that because of their buoyancy the continents spread horizontally that pushed the adjacent plates under.

Rey said that the spread of early continents could have caused the movement of plate tectonics until the Earth's interior cooled and the crust and mantle became heavier.

This cause plate tectonics to become self-sustaining that has never stopped and shaped the face of the modern Earth, he concluded.