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. 7.21).

Detailed explanation-2: -These plates move due to convection currents in the mantle . Heat from the core makes magma in the mantle rise towards the crust. As the hot current nears the crust, it begins to cool and sink back towards the core. As the magma sinks, it drags the plates across the surface of the Earth.

Detailed explanation-3: -Convection currents are the result of differential heating. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.

Detailed explanation-4: -The plates move on a hot flowing mantle layer called the asthenosphere, which is several hundred kilometers thick. Heat within the asthenosphere creates convection currents (similar to the currents that can be seen in the lava lamp).

Detailed explanation-5: -The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.