Pollution

The term pollution refers to the act of contaminating ones environment by introducing certain hazardous contaminants that disturb the ecosystem and directly or indirectly affect the living organisms of that ecosystem. Pollution in general is the activity of disturbing the natural system and balance of an environment.
The increase in the pollution over the years by man has caused severe damage to the earth’s ecosystem. It is responsible for global warming which is leading to the end if all the lives on earth. Over the years there is an extreme increase in the rate of human diseases, and death rate of various animals and plants on earth, and that is all because of the pollution caused by man himself.
There are many types of pollution, but four of them have the most perilous affect on our lives. Following are the four most dangerous types of pollution and their causes:

Types of Pollution

                                                                                     Air Pollution 
Air pollution is perhaps the most common and the most dangerous type of pollution. It involves the direct release of chemicals into the
environment. The chemicals then become the part of the air around us that all the living things take in. The increase in the rate of diseases such as asthma and lung cancer today is due to the increase in the air pollution around us.
Air pollution is also a cause of global warming and acid rain.

Causes Of Air Pollution
Basically the air pollution is caused by the burning of fuel that directly releases hazardous chemicals into the air. For example the burning of coal releases sulphur dioxide, a poisonous gas which is responsible for acid rain. The sources of such chemicals are the large factories, smoke from the vehicles, chimneys and burning of wood. Threat To Polar Animals Due To Global Warming The effects of global warming are playing havoc everywhere higher temperatures, hurricanes, heavy rains, flooding and droughts have now become more frequent and severe in intensity.

Soil Pollution
Soil pollution involves the contamination of soil by the release of harmful substances into the soil. Unlike air pollution, which has a direct affect on human lives, soil pollution causes an indirect
damage to humans and other animals.
The lives of all the living things depend on three sources: water, light and soil. The plants which are the producers of the food chain take up their nutrients, which are essential for their living, from the soil.
The nutrients taken by the plants are then transferred to the consumers that depend on these plants. Hence a soil consisting of contaminants will not only affect the plants growing on the soil
but it will also indirectly harm the entire food chain.

Causes Of Soil Pollution
Soil pollution is mainly caused by the release of industrial waste.
This waste is directly incorporated into the soil by large industries and factories. Soil pollution is also caused by human acts as mining and deforestation etc.

                                                                                   

                                                                                    Water Pollution
The 75% of the earth’s surface is covered with water and more that half of the total population of earth’s species resides in water.
Moreover, our life greatly depends on water and life without water is impossible. Water pollution not only affects the fish and animals living
in the water but also affects the whole food chain by also transferring the contaminants to the consumers depending on these animals. Water used from a polluted lake directly contaminates its user.
Many of the water creatures are on the verge of extinction due to the dramatic increase in the water pollution.

Cause Of Water Pollution
Just like air and soil pollution, water pollution is caused by the direct incorporation of hazardous pollutants. The sources of these pollutants are yet again the large industries
and factories that dispose off their waste in lakes and ponds.


                                                      
           
                                                                                   
                                                                                    Noise Pollution

Unlike other the above mentioned types of pollution does not involve hazardous chemicals or their incorporation into the environment, rather noise pollution is the increase in the rate of
noise in the environment.
Noise is defined as an unpleasant sound that has an adverse effect on the human ear. Noise can be extremely dangerous. And it is all around us. It
penetrates into human mind and controls it.
Too much noise leads to severe psychological illness and badly affects the behavior.
It leads to hypertension, stress, aggression and annoyance. Moreover, it causes depression and forgetfulness.

Cause Of Noise Pollution
Noise pollution is caused by the moving vehicles, man made machines and loud music. Other than that noise can be caused by anything, but these three sources are the main reasons for the noise pollution around us.

Earthquake

From Wikipedia, the free encyclopedia

For other uses, see Earthquake (disambiguation).

"Seismic event" redirects here. For seismic migration, see Seismic migration.

Global earthquake epicenters, 1963–1998

Global plate tectonic movement

An earthquake (also known as a quake, tremor or temblor) is the perceptible shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes can be violent enough to toss people around and destroy whole cities. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time.
Earthquakes are measured using observations from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe. The more numerous earthquakes smaller than magnitude 5 reported by national seismological observatories are measured mostly on the local magnitude scale, also referred to as the Richter magnitude scale. These two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly almost imperceptible or weak and magnitude 7 and over potentially cause serious damage over larger areas, depending on their depth. The largest earthquakes in historic times have been of magnitude slightly over 9, although there is no limit to the possible magnitude. Intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the more damage to structures it causes, all else being equal.^[1]
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity.
In its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter.


Do's during earthquake

• If you're indoors, stay there. Get under -- and hold onto --a desk or table, or stand against an interior wall. Stay clear of exterior walls, glass, heavy furniture, fireplaces and appliances. The kitchen is a particularly dangerous spot. If you’re in an office building, stay away from windows and outside walls and do not use the elevator.
   
• If you're outside, get into the open. Stay clear of buildings, power lines or anything else that could fall on you.
   
• If you're driving, move the car out of traffic and stop. Avoid parking under or on bridges or overpasses. Try to get clear of trees, light posts, signs and power lines. When you resume driving, watch out for road hazards.
   
• If you're in a mountainous area, beware of the potential for landslides. Likewise, if you're near the ocean, be aware that tsunamis are associated with large earthquakes. Get to high ground.
   
• If you’re in a crowded public place, avoid panicking and do not rush for the exit. Stay low and cover your head and neck with your hands and arms. 
  
  
  
  
  
  
                                                                                        
  
  
  Dont's during earthquake
   
  What rescuers and experts DO NOT recommend you do during an earthquake
  Based on years of research about how people are injured or killed during earthquakes, and the experiences of U.S. and international search and rescue teams, these three actions are not recommended to protect yourself during earthquakes:
  DO NOT run outside or to other rooms during shaking: The area near the exterior walls of a building is the most dangerous place to be. Windows, facades and architectural details are often the first parts of the building to collapse. To stay away from this danger zone, stay inside if you are inside and outside if you are outside. Also, shaking can be so strong that you will not be able to move far without falling down, and objects may fall or be thrown at you that you do not expect. Injuries can be avoided if you drop to the ground before the earthquake drops you.
  DO NOT stand in a doorway: An enduring earthquake image of California is a collapsed adobe home with the door frame as the only standing part. From this came our belief that a doorway is the safest place to be during an earthquake. True- if you live in an old, unreinforced adobe house or some older wood-frame houses. In modern houses, doorways are no stronger than any other part of the house, and the doorway does not protect you from the most likely source of injury- falling or flying objects. You also may not be able to brace yourself in the door during strong shaking. You are safer under a table.
  DO NOT get in the “triangle of life”: In recent years, an e-mail has been circulating which describes an alternative to the long-established “Drop, Cover, and Hold On” advice. The so-called “triangle of life” and some of the other actions recommended in the e-mail are potentially life threatening, and the credibility of the source of these recommendations has been broadly questioned.
  The “triangle of life” advice (always get next to a table rather than underneath it) is based on several wrong assumptions:
  
• buildings always collapse in earthquakes (wrong- especially in developed nations, and flat “pancake” collapse is rare anywhere);
• when buildings collapse they always crush all furniture inside (wrong- people DO survive under furniture or other shelters);
• people can always anticipate how their building might collapse and anticipate the location of survivable void spaces (wrong- the direction of shaking and unique structural aspects of the building make this nearly impossible) ; and
• during strong shaking people can move to a desired location (wrong- strong shaking can make moving very difficult and dangerous).

Some other recommendations in the “triangle of life” e-mail are also based on wrong assumptions and very hazardous. For example, the recommendation to get out of your car during an earthquake and lie down next to it assumes that there is always an elevated freeway above you that will fall and crush your car. Of course there are very few elevated freeways, and lying next to your car is very dangerous because the car can move and crush you, and other drivers may not see you on the ground!