GEOLOGY

Detailed explanation-1: -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. The long-term result of plate tectonics is the movement of entire continents over millions of years (Fig.

Detailed explanation-2: -Heat from the core and the mantle itself causes convection currents in the mantle. Hot columns of mantle material rise slowly. At the top of the asthenosphere, the hot material spreads out and pushes the cooler material out of the way. This cooler material sinks back into the mantle.

Detailed explanation-3: -Magma is the molten rock below the crust, in the mantle. Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth’s crust.

Detailed explanation-4: -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-5: -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.