GEOLOGY

Detailed explanation-1: -Convection currents drive the movement of Earth’s rigid tectonic plates in the planet’s fluid molten mantle. In places where convection currents rise up towards the crust’s surface, tectonic plates move away from each other in a process known as seafloor spreading (Fig.

Detailed explanation-2: -The common, simplified explanation for why tectonic plates are moving is that they’re carried along on currents in the upper mantle, the slowly flowing layer of rock just below the Earth’s crust. Converging currents drive plates into each other.

Detailed explanation-3: -Convection currents: Movement caused by the gain and loss of heat energy. In the Earth’s mantle, the mantle closest to the core gains heat energy and becomes less dense than the surrounding cooler mantle. As it becomes less dense, it rises towards the crust.

Detailed explanation-4: -The primary sources of thermal energy for mantle convection are three: (1) internal heating due to the decay of the radioactive isotopes of uranium, thorium, and potassium; (2) the long-term secular cooling of the earth; and (3) heat from the core.

Detailed explanation-5: -The mantle is heated from below (the core), and in areas that are hotter it rises upwards (it is buoyant), whereas in areas that are cooler it sink down. This results in convection cells in the mantle, and produces horizontal motion of mantle material close to the Earth surface.