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Interior Structure of the Earth

Earth has a diameter of about 12756 km at equator & about 12715 km at the poles. The Earth’s interior consists of rocks & metals & has 4 layers.
1. The Crust or the top layer of the earth.
It sustains life on the earth. It is made of igneous rocksmetamorphicrocks & sedimentary rocks. The crust is made of 2 layers—
(1) outer layer orsial which is made of silica & aluminum
(2)  inner layer or sima made of basalt & magnesium.
2. Mantle is the 2nd Layer of the earth made of silicate rocks rich in iron & magnesium. The mantle is divided into upper mantle and lower mantle.
Upper mantle consists of lithosphere & asthenosphere. Lithosphere is the hard rock layer of the mantle& the asthenosphere hemisphere is made of viscous yet solid rock.
  • Outer core – made of liquid iron & nickel.
  • Inner core- innermost & deepest Layers It is extremely hot with high pressure and this causes the contents of the inner core to remain solid.
  • The crust forms only 0.5 % of the volume of the Earth, 16% consists of the mantle & 83% makes up the core.
  • The radius of the Earth is 6371 km
  • Core is also called “nife” as it made of ni-nickle & fe-iron (ferrous)
  • The crust of the earth is made of various types of rocks (natural mass of mineral matter).
  • Rocks are of different colour, size, texture.
  • There are 3 major types of rocks
  1. Igneous
  2. Sedimentary
  3. Metamorphic