Thread by @UPSC_Notes

■ INTERNAL STRUCTURE OF THE EARTH.

#interiorofearth

◇ The interior of the earth is made up of several concentric layers of which the crust, the mantle, the outer core and the inner core are significant because of their unique physical and chemical properties.

◇ The crust… twitter.com/i/web/status/1…

■ THE CRUST

#interiorofearth

◇ The crust is the outermost layer of the earth making up 0.5-1.0 per cent of the earth’s volume and less than 1 per cent of Earth’s mass.

◇ Density increases with depth, and the average density is about 2.7 g/cm3 (average density of the earth… twitter.com/i/web/status/1…

■ THE MANTLE

#interiorofearth

◇ It forms about 83 per cent of the earth's volume and holds 67% of the earth’s mass.

◇ It extends from Moho’s discontinuity to a depth of 2,900 km.

◇ The density of the upper mantle varies between 2.9 g/cm3 and 3.3 g/cm3.

◇ The lower… twitter.com/i/web/status/1…

■ THE OUTER CORE

#interiorofearth

◇ The outer core, surrounding the inner core, lies between 2900 km and 5100 km below the earth's surface.

◇ The outer core is composed of iron mixed with nickel (nife) and trace amounts of lighter elements.

◇ The outer core is not under… twitter.com/i/web/status/1…

■ THE INNER CORE

#Interiorofearth

◇ Inner core extends from the centre of the earth to 5100 km below the earth's surface.

◇ Inner core is generally believed to be composed primarily of iron (80%) and some nickel (nife).

◇ Since this layer can transmit shear waves… twitter.com/i/web/status/1…