GEOLOGY

Detailed explanation-1: -Three factors contribute to set convection currents in motion: heating and cooling of the fluid, changes in the fluid’s density, and force of gravity. Note: Convection currents are responsible for the movement of the tectonic plates that make up the earth’s crust, not the entire planet.

Detailed explanation-2: -Convection occurs in the asthenosphere and elsewhere in the mantle because heat is generated in Earth’s core. This heat causes molten rock to rise and turn over, and this convective activity extends as far up as the asthenosphere where rock is partially melted and viscous enough to take part in convection.

Detailed explanation-3: -Answer and Explanation: Convection occurs in the asthenosphere due to heat generated in Earth’s core. This heat drives convection currents throughout the mantle because magma is able to move as a viscous fluid, rising and turning over again as it is heated from below.

Detailed explanation-4: -Heat from deep within Earth is thought to keep the asthenosphere malleable, lubricating the undersides of Earth’s tectonic plates and allowing them to move. Convection currents generated within the asthenosphere push magma upward through volcanic vents and spreading centres to create new crust.

Detailed explanation-5: -Convection currents are heat-driven cycles that occur in the air, ocean, and mantle. They are caused by a difference in temperature, often due to a differing proximity to a heat source. The difference in temperature relates directly to the density of the material, causing this effect.