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

Useful instruction for stock verification and maintenance , Useful Instruct...

Useful Instruction : You should go through of LT-1 course before doing this exercise. This exercise is a mix of demonstration and hands on activities. Take the help of your counse

Other visible light hazards-lasers, Other visible light hazards : Ordinary...

Other visible light hazards : Ordinary, visible light can present a hazard under certain conditions. You can burn paper by focussing the sun's rays using a small magnifying lens.

Control and coordination, what is the regulation of steady conditions insid...

what is the regulation of steady conditions inside an organism

Crytosporidiosis, 3 reasons why Minnesota still has crytosporidiosis

3 reasons why Minnesota still has crytosporidiosis

Social science, discuss the importance of society and culture to existence ...

discuss the importance of society and culture to existence of man .

Weather, which instrument measure the air pressure

which instrument measure the air pressure

A lamp chimney force pump, A lamp chimney force pump Replace the piston...

A lamp chimney force pump Replace the piston in the lift pump explained above with a one-hole stopper. Fit the piston rod by the hole. Fit the bottom of the chimney with a two-

What is the major source of water in city, Q. What is the major source of f...

Q. What is the major source of fresh water in the city/town/village where you live? Answer : River is a major source of fresh water.

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