Interior Structure of Earth

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Earth’s Profile
Our planet Earth has an average radius of 6378 km and a mean mass density of 5.527 g/cm3 compared with a mean mass density of soil particles of 2.7 g/cm3 and water of 1 g/cm3. The earth has a core of heavy metals, mostly iron, of mass density 8 g/cm3 surrounded by a mantle. The mantle consists of two parts, upper mantle and lower mantle. The upper mantle is solid rock while the lower mantle is molten rock. Above the upper mantle is the crust, which may be as much as 50 km thick in the continental areas and as little as 7 km thick in oceanic areas.


Interior Structure of Earth according to Chemical properties  

Crust:

The outer most rock layer of the earth is called crust and it is divided into two parts

1.     Continental Crust (0-90 Km)
2.     Oceanic Crust (6-11 Km)

Mainly this layer contain Silicon (Si), and Oxygen (O₂) nearly 74% (Silicate-SiO₂) and the temperature 0⁰ C-48⁰ C

Composition : Iron, Oxygen, Silicon, Magnesium  and Aluminium (Oceanic Crust) Granite, Sedimentary rock and metamorphic rock (Continental Crust)

Mantle:

The mantle is the dense and mostly solid Silicate (SiO₂) and also contain Iron, Sodium, Silicon, Magnesium  and Aluminium.The mantle stretches from below the crust to 2900 Km. The upper part is partially molten (plastic) and the lower part is very dense.

This layer can be divided into two parts.

1.     Upper mantle (100-660 Km)
2.     Lower mantle (660-2900 Km)

Core:

The core is about 6400 KM in radius with a temperature of 4600- 6000⁰ C and pressure of over 3 million atm. The inner core is a lumpy solid iron sphere and outer core is a thick liquid iron layer and also contain Iron, Nickel, Sulfur and Oxygen.

Liquid layer of Iron and Nickel 5150 KM deep. The outer core flows arround the the center of the earth and the movement of the mantle create magnetic field. 

Mechanical Layers of the Earth

The earth is also divided up into 5 layers based upon the physical properties of each mechanical layers

Compression of Compositional layers and Mechanical Layer  

  1. Lithosphere : The crust and the upper layer of the mantle up a zone of rigid, brittle rock called the lithosphere. About 100 Km thick.
  2. Asthenosphere : A thin zone that lies below the lithosphere; Its material behave like flowing plastic; Region of upper mantle.
  3. Mesosphere : It consists of most of the lower mantle.This part of the mantle flows, but at much slower rate then the asthenosphere. 
  4. Outer core : It is liquid and composed of the melted metals of molten iron-nickel.
  5. Inner core : It is called Iron-nickel alloy; High temperature and pressure  
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