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

Genotype and phenotype, on my homework I have to create a super baby, and s...

on my homework I have to create a super baby, and so I had to have a female super hero and male super hero. I then have to list traits, hair color, eye color and one power from bot

Lungs, what are alveoli?

what are alveoli?

Antibody mediated immune system (amis), Antibody Mediated Immune System (AM...

Antibody Mediated Immune System (AMIS) In antibody-mediated immunity, the antibodies dissolved in blood, lymph and other body fluids bi nd the antigen and trigger a response to

What is the meaning of dry manure, What is Dry manure Dry manure thoug...

What is Dry manure Dry manure though contains 80 percent carbon, yet it is considered primarily as a nitrogen fertilizer and, to a lesser extent, one of potassium. Losses of nu

Moving water by reducing air pressure, Moving water by reducing air pressur...

Moving water by reducing air pressure Secure two small bottles. Fill single about half full of water and close it with a single-hole stopper carrying a length of glass tube tha

The main purpose of dressing-controlling bleeding, A wound should be cleane...

A wound should be cleaned first and covered with a protective dressing. The main purpose of dressing is to: (1) prevent infection, (2) control bleeding, (3) absorb any dis

Define the sources of sound and their level of loudness, Define the Sources...

Define the Sources of sound and their level of loudness Let us now have a look at Table, where the various sources of sound, their level of loudness and its comparison to the f

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