Explainbasicfeaturesoftheinterioroftheearth

The earth is made up of several concentric layers. The main three layers of the earth are as under:

1. The crust: It is the outermost layer over the earth’s surface. It is the thinnest of all the layers and about 35 km on the continental masses and only 5 km on the ocean floors. The main minerals constituting the continental mass are – silica and alumina. The continental mass is also called ‘sial’. The main mineral constituents of the oceanic crust are –silicon and magnesium. The oceanic crust is called ‘sima’.
2. Mantle: It is the layer just beneath the crust and extends up to a depth of 2900 km below the crust.
3. The core: It is the innermost layer i.e. it is below the mantle. Its radius is about 3500 km. The core consists of outer core and inner core. It is mainly made up of – nickel and iron. The innermost layer is also called nife. The name ‘nife’ is derived from the word ‘ni’ from nickel and ‘fe’ from ferrous meaning iron. The temperature and pressure of the central core is very high.