The correct option is (c).
Explanation
The theory of Plate Tectonics describes the large-scale motion of the Earth's lithosphere. The lithosphere is broken into distinct tectonic plates that float on the semi-fluid asthenosphere.- Statement 1 is Correct: Lithospheric plates are in constant motion, but they move extremely slowly. The speed of this movement is typically measured in terms of a few millimetres to a few centimetres each year. This gradual movement is responsible for significant geological changes over millions of years.
- Statement 2 is Incorrect: The movement of lithospheric plates is not driven by the rotation of the Earth on its axis. While early theories like Continental Drift proposed forces such as the "pole-fleeing force" related to rotation, modern Plate Tectonics attributes the movement to endogenic forces originating from within the Earth.
- Statement 3 is Correct: The primary driving force behind plate movement is the convection currents within the mantle. The molten magma inside the Earth moves in a circular manner: hot magma rises, spreads horizontally, cools, and sinks. These convection cells create the drag and force necessary to move the overlying lithospheric plates.
Key Takeaway: The movement of lithospheric plates is driven by circular convection currents of molten magma in the mantle, not by the Earth's rotation.