Important points about the Interior Structure of the Earth

In continuation to the Geography Notes which we provided earlier, today we will be covering a very Important Topic from the Geography Part of the General Knowledge section on the topic "Important points about the Interior Structure of the Earth". A good number of questions from this topic are asked from this topic in every exam. Thus, the post is very helpful for the upcoming SSC Exams 2017.

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 rocks, metamorphicrocks & 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.

Facts:-

• 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