How are plate tectonics formed?
1 Answer
Due to convectional currents in the earth's mantle.
Explanation:
Earth's mantle contains molten magma, liquid rocks. The magma forms due to the extreme heat and pressure in the mantle, generated by the nuclear decay of unstable elements underneath.
Picture a water boiling in a pot. Since the heat source is only from the bottom, as water molecules at the bottom pf the pot heat up, they gain more kinetic energy and spread out a little bit, increasing volume, and decreasing density. The warmer or less dense particles rise upwards, and are replaced by the cooler, denser ones.
The same effect takes place on the previously cooler molecules, and the rise upwards. By this time, the molecules above lose energy to the air and through evaporation, and return back down. This generates a cycle of constantly rising and falling molecules, creating convectional currents.
The same phenomenon occurs in the earth's mantle, generating a force against the plates in the crust, resulting in tectonic movements.
