Earth, Science

Assignment Help:

Earth

How do we describe the 'big ball' on which we live? Seen from space, it appears as a bluish-white sphere. Its wealth of plant and animal life, snow covered peaks, blue oceans and white clouds make the Earth a beautiful planet. Human beings have explored it extensively. Yet, the first hand knowledge of  the Earth is limited to a thin shell of  rock and water extending to a few kilometres below the surface, and to the atmosphere above. However, using indirect methods, such as the study of waves generated during earthquakes, scientists have been able to picture the Earth's interior. without ever seeing or sampling it. We will now briefly describe the current scientific knowledge about the Earth. 

 

1094_Earth.png

The Earth's  atmosphere has been studied extensively with  the help of ground based experiments, aircraft, rockets and balloons. Though it  is not divided  into distinct layers, it-is helpful to think of  the atmosphere in this way. The troposphere, nearest to the surface,  is made up of  78 per cent nitrogen and 21 per cent oxygen, with water vapour, carbon dioxide, neon and argon making up most of  the remaining one per cent. It has an average temperature of about 16°C at sea level and-  16OC near its top. The stratosphere, coming next contains ozone and has a temperature ranging from -  16OC to -4OC.  This ozone layer absorbs the harmful UV radiations fron, the Sun,  thus protecting us from them. The carbon dioxide in the Earth's atmosphere traps heat and makes it warmer through the greenhouse effect. Were it not for this, the Earth's surface temperature would be much lower and it would always be covered with ice.


Related Discussions:- Earth

The difference between hard and soft water, The difference between hard and...

The difference between hard and soft water Collect some hard water from a stream(or make some as defined in the next experiment). Also secure some soft water like as rain wate

How old is the earth, How old is the earth Ans) The earth has only very...

How old is the earth Ans) The earth has only very freshly been accurately dated. Until astonishingly recently, the earth was thought to be anywhere among a few hundred thousand

History of the earth, The Early History of the Earth The Earth has be...

The Early History of the Earth The Earth has been evolving and changing ever since its origin, about 4.5 billion years ago. In the first  tens of millions of years of  the Ea

Marshall Island Restoration Plan, What is necessary to restore the Marshall...

What is necessary to restore the Marshall wetland in Margibi County, Liberia? The Marshall wetland has several features , including mangrove swamp, which is being degraded in some

A field trip to a rock quarry, A field trip to a rock quarry The quarry...

A field trip to a rock quarry The quarry should be visited by the teacher in advance. View how the rock is removed. If the rock is sedimentary, view the layers. Collect rock sa

Chromatin, What is the job of chromatin in an animal cell?

What is the job of chromatin in an animal cell?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd