what is the earth - Let's Crack It
WHAT IS THE EARTH:
A Greek philosopher and mathematicians, was the first to suggested that the Earth was Shaped like a Globe :
Generally the Earth is made up of three states:
1. Solid
2. Liquid
3. Gas
● If the Earth were a flat disc, then the rising Sun would have been seen at all places at very accurate time of the world.
● When a ship approaches land, its funnel or mast is seen first and then the hull. If the Earth had been flat then the whole ship would have been seen at the same time as we seen the another once .
● The Earth is rarely oriented in the accurate position during successive eclipses but it always be casts a circular shadows thus providing that the Earth shapes like sphere.A sphere is the only body that will always casts a circular or spherical shadows around the same time.
● At the North pole, the pole star can always been observed at 90 degree in the Sky, Since the star lies in the line with the angle of the Earth.
● As one of it can travel southwards, the angle of that pole star had been decreased.
● At the equator , the angle always becomes zero degree.
● This observation always proves that the path of travel is just an arc of a circle.
● The Sun, Moon and all the heavenly bodies appears to be just like Earth or spherical when viewed from different positions. It seems logical to its to conclude that the Earth is no exceptions at all.
● The pictures of the Earth taken from the space always proved beyond any doubts that the Earth is a sphere.
THE EARTH AS AN OBLATE SPHEROID:
● Such Refined measurement of the Earth had been proved that the true form of the Earth resembles a sphere that has been Compressed at the poles and made to bulge at the Equators. This is the firm which known as an oblate spheroid.
The various factories which makes the earth such suitable for the life to evolve and survive are:
● The earth has all the famous elements like carbon, hydrogen , nitrogen and oxygen, which acts as building block for the origin of life.
● The earth is neither too hot nor too cold , it has the medium temperature range for carrying out the life - sustainable chemically proved reactions.
● The earth has such lot of water in the form of lakes , rivers and too much oceans for the proper growth and survivals of life.
● The earth has enough oxygen gas in its atmosphere for the survival of living beings through breathing.
● The earth has a hard and protective blanket of the ozone layer high up in its temperature as well as atmosphere to save life from some harmful ultraviolet radiations that coming from the sun.
● Biodiversity changes and it goes increases towards the equator. Biodiversity is the degree of the variations of the life . It is the measure pf some variety of the organisms that present in different ecosystems. It the most richest in the tropics.
STATISTICAL DATA OF THE EARTH:
● The Earth , third planet from the sun, is the fifth largest in the Solar System in terms of its size and mass.
● 29.1% of the total surface area of Earth is covered by the lands , while 70.9% is get covered by the oceans.
● The total water areas of the earth including the oceans , lakes , rivers , ice sheets , and the water in the atmosphere is known as hydrosphere and it covers about 71% of the earth’s surface.
OCEANS ON THE EARTH:
There are four oceans . in this ,their size , they are :
1. Pacific Ocean
2. Atlantic Ocean
3. Indian Ocean
4. Arctic Ocean
● PACIFIC OCEAN:
The explorer F. MAGELLAN, whole circumnavigation of the Earth, named the ocean ‘Pacific’ meanings that such a kind of calm and peacefully.
The Pacific Ocean is one of the most largest ocean of the world.
It is also one of the most deepest ocean with an average depth of 4,280 m. (14,040 feet).
Most of the islands of this ocean are the volcanic or coral origin.
● ATLANTIC OCEAN:
The Atlantic Ocean according to Encyclopaedia British, is the second largest ocean in the world
Average depth: 3,300 meters.
The Atlantic Ocean , body of salt water covering one fifth of our earth surface has the as such longest coastline.
The continental islands of Newfoundland and British isles are the most major ones.
● INDIAN OCEAN:
The Indian Ocean is the one and only ocean named after a country. Its average depth is 3,960 meters.
The Indian Ocean is deeper than the Atlantic Ocean.
Some of the islands of volcanic origin are those of Mauritius , Andaman and Nicobar , Seychelles , and Maldives are of such coral origin.
● ARCTIC OCEAN:
The Arctic Ocean is the smallest ocean in the world.
It lies around the Arctic Circle , hence the name Arctic Ocean.
The Most of its part of Arctic ocean remains frozen with some thick ice fir most of the days every year.
It has the least salinity of all the oceans.
Its about salinity of 30ppt.
INTERNAL STRUCTURE OF THE EARTH:
1. The Earth Crust:
The outermost solids of its cover or shell of the earth , that called as the earth’s crust.
The thickness of the crust is about 30kms.
The density of the rocks in the earth’s crust ranges from 2.7 to 3 g/ c.c .
The upper part of the crust consists of silica gel in greatest portions.
Its known as ‘SAIL'.
2.MANTLE:
This layer lies below to the crust. The lower part of the crust is known as ‘SIMA. because the portion of its is higher in such parts.
Its thickness is all about 2900 km and the density of the substances in the mantle ranges from 3.0 to 4.7.
3. CORE:
The earth's core lies below the mantle, Its thickness may be about 3,471 km.
Its radius is 6,371kms, according to,the study of earth's interior helps us to understand how the original rocks in the earth's crust and their later transformation.
4. ROCKS:
The solid parts of the earth's crust are always known as rocks.
Most of the rocks are made up of two or more minerals.
In the same type of rocks, the proportions of minerals may be suck different in different areas.
Rocks may not always necessarily be hard.
This is all about earth..
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