Internal structure of Earth
The Geology of Earth is complex so
that why the internal structure is divided into three parts
1) Crust 2)
Mantle 3) Core
It is easy to study and understand
the internal structure of Earth by this division. Geologist can easily identify
and study the nature of rock and minerals.
1) The Crust:
- It is the upper most part of Earth; it is solidified and hard which composes
of different rocks. The Earth crust is divided into two part
i) Continental Crust
ii) Oceanic Crust
i) Continental Crust: - Continental Crust is the
continental shelf or part of earth and under the mountains. Continental Crust
is lesser denser and mostly light rocks are formed. Continental Crust is rich
in Si and Al and termed as SIAL Crust. Continental Crust thickness ranges from
30 to 100km. Specific gravity of Continental Crust is 2.7 to 2.9.
ii) Oceanic Crust:- Oceanic Crust is too much denser
then Continental Crust. Oceanic Crust is dark in color. Oceanic Crust is
composed of Si and Mg it is term as SIMA.
Specific gravity of Oceanic Crust is 3.5 to 4.1. Dark and heavy minerals
are found in Oceanic Crust.
The line or separation between Crust and
Mantle is known as Mohorovicich Discontinuity.
2) Mantle:- It is semi-molten form, all the rocks
are in molten form. 84% of Earth’s volume is made up of mantle. 2,886(1,793
mil) average thickness of mantle.
Geologist
always go for a easy way to understand the Geology so for that purpose Mantle
is divided into further more part
i) Upper mantle ii)
Lower mantle
i) Upper mantle: - Upper mantle is semi-molten material;
Upper mantle is composed of Si and Mg minerals.
ii) Lower Mantle: - Lower Mantle has hot molten material;
Lower Mantle is Si and Mg rich minerals. The Lower Mantle has too much
temperature then upper mantle.
After the Lower
mantle Gutenberg Discontinuity starts which separates mantle from core.
3) The Core:
- Core is the most inner part of Earth, The Core is thicker then crust and
Mantle. The Core show real composition of Earth. The Core is mostly rich in Fe
and Ni, same as a meteorites tells us that all the solar system is derived from
one and same body.
To understand the mystery of core Geologist had divided the Core into
two parts
i) Outer Core ii) Inner Core
i) Outer Core: - Outer Core is totally in molten form,
Outer Core is composed of SIMA as well as little bit S, Ni and Fe in small
content. Due to high pressure this portion behaves like solid but it is in melt
form.
ii) Inner Core : - Inner Core is also in molten , Inner
Core the portion where too much heat and pressure. Due to high pressure it
totally behaves like solid material. Ni and Fe are the main of which Inner Core
is compose of.
Lithosphere:
- Crust and Upper makes up the Lithosphere. It is the hard portion of Earth
mostly rocks are formed and found.
Asthenosphere: - It is
highly viscous material and ductile in nature. Lithosphere lies above the
Asthenosphere.
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