Natural disasters are a test or significant damage caused by a natural event inclosed risk (hazardous), such as volcanic eruptions, earthquakes, hurricanes and other natural phenomena that cause significant damage to property and human beings, in the event of natural phenomena in uninhabited areas are not called natural disasters. Different disasters by the proportion of people surrounding a natural phenomenon of folding or are at risk, many of the communities living near the volcano with a history of devastating, as happened in Pompeii, etc. This is due to human nature and the problems of poverty and others.
They are divided into:
What is the hurricane:
Pneumatic rotary storms are violent spiral, usually arise over tropical seas, and therefore known as typhoons or tropical cyclones or because the cold air) a high pressure) around the center where there is resident of warm air
(The low pressure), then this storm surges in the direction of land deprives the velocities of friction with the Earth's surface, but still moving at speeds of up to more than 300 kilometers per hour. The diameter of the vortex per 500 kilometers, and may continue for several days to two weeks in a row. And accompanied by that all the clouds Layering and cumulus to the high of 15 kilometers and is moving hurricane in straight lines or curved which makes her enormous devastation on the land because of the speed of the big flash, and accompany heavy rains and floods and floods, in addition to the phenomena of lightning and thunder, as it may cause a hurricane in the high waves Sea.
How does a hurricane:
Consists of hurricanes in the tropics where there is warm water (not less than 27 degrees Celsius) and moist air and the winds of Tropical Convergent.
And start most of the Atlantic hurricanes of the west coast of Africa and start Kaaoasf thunderstorm moved over the warm tropical waters of the ocean waters.
And thunderstorms to reach hurricane status on multiple stages, the first tropical depression and the withdrawal of circular and rain with wind speed less than 38 miles per hour,
The speed of the winds of Tropical Storm from 39 to 73 miles per hour, the hurricane Vtkon speed of more than 74 miles per hour may take from hours to several days to develop a thunderstorm to a hurricane.
As the world is witnessing a catastrophic hurricane in different areas, know Come together on them and on Bayaha,
According to a specialist that hurricanes have become more destructive over the past thirty years. Specialists and found that both the duration of tropical cyclones with wind speeds have risen by 50% with the increase in the average surface temperature of tropical oceans.
It may be the earliest example of this is Hurricane Katrina, which hit the city of New Orleans of America, which is one of the strongest hurricanes 150 years ago
Third: The parts of the hurricane:
When a hurricane, we find that consists of three parts:
Al Ain: center of rotation and has low pressure and quiet
Eye wall: The area around the eye and had the fastest and fiercest winds
Rain waves: waves of thunderstorms, which revolve around the direction of the external eye, part of the cycle of evaporation, condensation, which feeds the storm.
IV: Size and location:
Cyclones vary in size, we find that some of the same small space, and leave behind a little rain and wind. And others are larger and wider spread and him with winds for hundreds or thousands of miles away.
Fifth: Hurricane Omar:
Hurricane Omar could reach to 10 days, and there are hurricanes remain much longer, often wandering
Hurricanes, a large area during the period of her life. The impact of the hurricane on an area, for a day or two days only. The most hurricanes do not reach to the maximum of its power before it reaches the stage of decay and extinction, both decreasing its strength on the surface of the ground or in the cold ocean
'It can be described as one of the most serious problems facing the environment par excellence, and is the main reason the climate is dry, and may continue to fire for months for not just days and resulting in many of the risks, especially for the emission of carbon monoxide poison. There are key factors in the outbreak of such fires are natural with no income for a person where, and human factors that a person is a hero: The most famous example of human factors such fires, which broke out in Indonesia on the islands of "Borneo" and Sue Marta "between the years 1997 to 1998. and emitted from the fires of toxic gases covered a large area of the South-East Asia, which resulted in the emergence of health and environmental problems, and fire broke out at about 808 sites have been identified satellite images and estimated the area destroyed by fire at about 456.000 hectares (45.600 square kilometers)
The main reason behind these fires to convert the production of these forests through the establishment of palm plantations for the production of oils. Not to mention the tragic loss of timber and wealth of plant and animal and human because of toxic gases to these fires spread to neighboring countries do not stop at the borders of a particular State. Other examples of forest fires that fire which broke out in Brazil in 1998 and that wiped out more than a million hectares of forest savannas have suffered Mexico also drought over seventy years has also led to the outbreak of fire to eliminate about 3.000 square meters of land and the spread of smoke to the southern United States of America. We can describe forest fires as the greatest environmental disaster of this decade, and a disaster for generations can not take any preventive action away from the policies and governments, but have to pay the price and suffer the consequences. Unfortunately, there is no serious body want to protect the interests of the unknown fate of this generation.
Ahtazar earthquake is the rapid return to the ground breaking rocks and removing it because of the accumulation of internal stresses as a result of geological effects caused by the movement of plate tectonics.
May arise as a result of earthquake or volcanic activities as a result of the presence of landslides in the layers of the earth. Cause earthquakes to rupture of the earth and the depletion of springs or the appearance of springs of new or the occurrence of high waves if they get below the surface of the sea as well as its sabotage of buildings and transportation, facilities and often result in movements of convection in Alostinosver that drive continental plates, causing the occurrence of earthquakes are earthquakes. The earthquakes may occur in ruins Ckbyrao determine the degree of earthquake Bmeshr and measured by from 1 to 10: 1 to 4 earthquakes may not occur any damage which may be a sense of it all, from 4 to 6 moderate earthquakes damage may cause damage to homes and residences, while the maximum score any of the 7 to 10 he can count the earthquake destroyed the entire city and dug under Atelard even disappear with damage to the nearby towns. Crack and crevices in the ground caused by earthquake 'definition of the earthquake' is a natural phenomenon
A ground vibration due to the fast break and dislodge the rocks due to the accumulation of internal stresses as a result of geological effects caused by the movement of plate tectonics. May arise as a result of earthquake or volcanic activities as a result of the presence of landslides in the layers of the earth. Cause earthquakes to rupture of the earth and the depletion of springs or the appearance of springs of new or the occurrence of high waves if they get below the surface of the sea (the tsunami) as well as its destructive to buildings, transportation and facilities and often result in movements of convection in Alostinosver that drive continental plates, causing the occurrence of earthquakes are earthquakes. Also, earthquakes may occur in ruins Ckbyrao determine the degree of the earthquake measured by Bmeshr and from 1 to 10: 1 to 4 earthquakes may not occur any damage can be any sense of it only, from 4 to 6 moderate earthquakes damage may cause damage to homes and residences,
The maximum score any of the 7 to 10 he can count the earthquake destroyed the entire city and dug under the ground until they disappear with damage to the nearby towns.
Largest earthquakes worldwide:
* Lisbon earthquake in 1755 killed between 60 to 100 thousand people and was one of the most devastating earthquakes in history.
* San Francisco earthquake in 1906 killed nearly 3 thousand people and its losses amounted to about $ 400 million and * had the most earthquakes in California
* Gujarat earthquake in western India, January 26, 2001.
* Bam earthquake in Iran which killed about 40 thousand people in it.
* Indian Ocean earthquake December 26, 2004 which was followed by months a tsunami which hit the coasts of many countries, including Indonesia, Sri Lanka, Thailand, India, Somalia and others where he described the quake as one of the worst natural disasters that hit the ground at all that killed nearly 250 000
* Kashmir earthquake 2005 that killed about 79 thousand people.
* Algeria earthquake (Boumerdes)
How composed Earthquakes:
During the process of vibration affecting the earth's crust generated six types of waves, shocks, two of which relate to the body of the earth where affect on the inner part of the land, while the four waves of the other are surface waves, and can distinguish between these waves also through the types of movements that affect the particles rocks, sending waves of primary or pressure waves particles oscillate back and forth in the same direction as the course of these waves, while the movement of waves or high transverse vibrations perpendicular to the direction of travel. Usually transmitted primary waves more quickly than secondary waves, and then, when an earthquake occurs, the first waves of up and recorded in the geophysical research stations all over the world are the primary waves
Appropriate action during the earthquakes:
*. If you stand in a building under the entrance door or under a table away from the window and glass.
• In the stop outside the building away from buildings, trees and telephone lines and electricity.
• If you are in the vehicle moved away from the tunnels and bridges and out of them.