GEOLOGY

Detailed explanation-1: -In plate tectonics, Earth’s outermost layer, or lithosphere-made up of the crust and upper mantle-is broken into large rocky plates. These plates lie on top of a partially molten layer of rock called the asthenosphere.

Detailed explanation-2: -The asthenosphere extends from about 100 km (60 miles) to about 700 km (450 miles) below Earth’s surface. 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.

Detailed explanation-3: -The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth’s mantle below the crust. Earthquakes and volcanoes are the short-term results of this tectonic movement.

Detailed explanation-4: -The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth’s mantle and fit snugly against one another. The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other.

Detailed explanation-5: -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).