The Structure Of The Earth

Have you ever wonder that, “What Does The Earth Looks Like”… like the structure of the earth, well you are about to find out.
Structure of the earth is the study of the layers, that comprises the earth surface which are divided into four distinct layers: The Crust, The Mantle and The core, yea I said four but this is three, don’t panic keep reading.

What does the earth looks like?

Structure Of The Earth

As mention above, the Earth is made of four layers Crust, Mantle and The core which is splitted into two part, Inner core and the outer core, I hope now you are clear about the statement make in the first paragraph.

I believed you have heard of these six distinct layers: The Atmosphere, Biosphere, Hydrosphere, Mesosphere, (mantle) Barysphere and (core) and Lithosphere (crust), so how come is the earth have four layers as to what is in the first paragraph, well let me explain.

In the structure of the earth, there is the outer or the external layer and also the inner or the internal layer, so one after the other.

So now ask yourself that question again, “what Does The Earth Looks like”, yea you know the answer.

Let talk about the inner layer first;

The Inner Layer Of The Earth

The inner or the internal layer of earth consist of Lithosphere: which is the crust, the Mesosphere: which is the mantle and the Barysphere: which is the core.

Before we keep going, let quickly get a brief explanation of the earth crust that we live in.

Explanation Of The Outer Layer Of The Earth Crust

The Earth Crust comprises of two distinct parts: the upper part and the lower part.

The upper part of the earth crust is made up of granite rocks and forms the continent with silica and alumina as its mineral constituents with an average density of 2.7 and is called Sial

The lower layer of the earth crust is constituted of basaltic rocks forming the silica, iron and magnesium of about average density of 3.0 and is called Sima.

Both Sial and Sima constitute the earth crust and lies beneath the ocean.

In some island area of the continent, the continent is said to be floating on the sea of sima due to the fact that sima is denser than sial

Before we keep going, please tell me you now know the answer to “What Does The Earth Looks Like ?” #Just checking in#
So if you do, then let continue.

So let go back to the structure of the earth and let start with lithosphere.


Lithosphere is a surface of discontinuity between the crust and the mantle which was discovered by a scientist called Mohoro and it is was name after him as Moho’s zone of discontinuity. Lithosphere exhibits a sudden increase in the speed of propagation of earthquake waves which indicates a changes in the structure of the rock.

As it has been mention earlier about sima as comprises of silicon, magnesium and iron and sial as comprises of silicon and alumina, they are both present inside lithosphere. Now let talk about characteristics of lithosphere.

Characteristics Of Lithosphere

1] Lithosphere is the outermost layer or zone of the earth crust.

2] Lithosphere is comprises of rock and minerals.

3] Lithosphere is the solid part of the earth.

4] The outermost layer, that is , “lithosphere” of the land mass is made up of loose rock materials such as sand, soil and ground.

5] Lithosphere represents 30% of the earth surface.

6] Lithosphere forms the land mass which is about 10 to 50km thick.

Important Or Advantage Of Lithosphere

a] Source Of Minerals : All mineral resources are derived from lithosphere.

b] Employment Opportunities : Most human activities such as trading, mining, farming, etc are executed on the lithosphere, hence it thus provide jobs.

c] Settlement Formation : All human settlement are formed by lithosphere.

Mesosphere Or Mantle

The Mesosphere lie beneath the lithosphere with very thick layer and of about 2900 km.
Mesosphere is made up of very denser rock materials which are rich in a constituent called Olivine. Olivine consists of Iron, Silicon and Magnesium

Now let talk about the core and probably atmosphere, Biosphere and Hydrosphere next class.

Barysphere Or The Core

Barysphere is believed to be liquid in nature because of the high pressure and temperature in the interior part of the earth.
There are two types of core – keeping reading to find out.

Characteristics Of Barysphere [The Core]

a] Barysphere has a diameter of about 7,000 km.

b] Barysphere is the hottest part of the earth with a temperature of about 2,000°C.
Hence, barysphere is subject to intense heat and pressure with high temperature.

c] Some of the rock present in barysphere are in molten state, that is, Semi-liquid, although some are still solid #put that in mind#.

d] Barysphere has a density of about 10.

e] Barysphere is rich in Iron and Nickel. Visit the chemistry class to know more about compound naming.

f] The Core, that is, barysphere has two core, The inner core and the outer core

Inner Core

Inner core, from its name, “inner”.
Inner core is the internal part of barysphere which is solid and firmly grip to the mantle.
In the characteristics of barysphere above, we said that some parts of baryshere are in molten state while some are in solid state. Well The solid part is The Inner core.

Characteristics Of The Inner Core

a] As mention above, it is solid in nature and attached to the mantle.

b] It consists of mainly iron.

c] It is suspended in the molten state of the outer core.

d] It is about 1.7% of the earth mass with a depth of about 5150 to 6370 km.

Now let talk about the outer core.

The Outer Core

The outer core is the external part of the barysphere which is molten, that is, semi-liquid in nature.

Characteristics Of The Outer Core

a] It is in molten state.

b] It consists of Iron, sulphur and sometimes oxygen.

c] The outer core is 30.8% of mass with a depth of about 2890 to 5150 km.

d] The outer core has a temperature of 3,700 °C. {The main reason for its molten form}.

e] Due to the convention motion and the rotation of the earth within the outer core, leads to creation of effects that maintains the magnetic field of the earth.

Let stop here for today, next class we will be talking about Atmosphere, Biosphere And Hydrosphere. By now you should know the answer, What does the Earth looks like ?

Is our session getting too long or too short?, please kindly let us know through the comment box and besides don’t forget to hit the share button, Plleeeaaaasssseee and write a comment. See you next class, until then, GOD BLESS ME.

-- Download The Structure Of The Earth as PDF --

One thought on “The Structure Of The Earth”

Leave a Reply