question_answer

Write briefly about the three main layers of the earth. Give a suitable diagram to explain it.

Answer:

                                There are multiple sections or layers of the earth namely, the crust, the mantle and the core. Geologists have named them as Lithosphere, Pyrosphere and Barysphere, respectively. The crust or the lithosphere is the thinnest layer 35-100 km thick. It is divided into two layers: · The lower crust is the oceanic crust and the rocks contain silicon (Si) and magnesium (mg)?also known as SIMA. It forms the base of ocean floors and continents. · The upper crust or SIAL is rich in Silicon (Si) and Aluminium (Al). It is a discontinuous slayer which forms the continents. The mantle is about 2900 km thick. The temperature is from \[100{}^\circ C\] to \[2200{}^\circ C\] the upper mantle is called the as the no sphere which is 100 to 250 km thick. This layer is viscous and partially melted in magma form. The magma in the asthenosphere induces convection currents which cause tectonic plates to move. The lower mantle is in semi-solid state and the temperature is around \[3000{}^\circ C\]. The core, the innermost layer, is made of dense rocks namely, Nickle (Ni) and Ferrous (Fe). This layer too is divided into two layers about 3500 km thick. The inner core is solid and the outer core is molten.