Science Fair Project Encyclopedia
A natural disaster is the consequence or effect of a hazardous event, occurring when human activities and natural phenomenon (a physical event, such as a volcanic eruption, earthquake, landslide etc. that does not affect human beings) become enmeshed. The resulting fatalities, or property damages depend on the capacity of the population to support or resist the disaster (Bankoff et al.2004). A disaster is a social disruption that can occur at any level of the individual, the community, or the State (Kreps 1986). In areas where there are no human interests, natural phenomena do not constitute hazards, nor do they result in natural disasters. This understanding is crystallized in the formulation: "disasters occur when hazards meet vulnerability" (Blaikie, 1994).
Common natural phenomena that can result in natural disasters
Blizzards and Snowstorms
A snowstorm is a winter storm in which the primary form of precipitation is snow. When such a storm is accompanied by winds above 32 mph that severely reduce visibility, it becomes a blizzard. Hazards from snowstorms and blizzards include traffic-related accidents, hypothermia for those unable to find shelter, as well as major disruptions to transportation and fuel and power distribution systems.
A drought is a long-lasting weather pattern consisting of dry conditions with very little or no precipitation. During this period, food and water supplies can run low, and other conditions, such as famine, can result. Droughts can last for several years and are particularly damaging in areas in which the residents depend on agriculture for survival. The Dust Bowl is a famous example of a severe drought.
An earthquake is a sudden shift or movement in the tectonic plate in the Earth's crust. On the surface, this is manifested by a moving and shaking of the ground, and can be massively damaging to poorly built structures. The most powerful earthquakes can destroy even the best built of structures. In addition, they can trigger secondary disasters, such as tsunamis and volcanic eruptions. Earthquakes occur along fault line, and are unpredictable. They are capable of killing hundreds of thousands of people, such as in the 1976 Tangshan and 2004 Indian Ocean earthquakes.
An epidemic is a massive outbreak and spread of an infectious disease, and is historically the most dangerous of all natural disasters. Different epidemics are caused by different diseases, and different epidemics have included the Black Death, smallpox, and AIDS. The Spanish flu of 1918 was the deadliest ever epidemic, it killed 25-40 million people. The Black Death, which occurred in the 14th Century, killed over 20 million people, one third of Europe's population.
Famine is a natural disaster characterized by a widespread lack of food in a region, and can be characterized as a lack of agriculture foodstuffs, a lack of livestock, or a general lack of all foodstuffs required for basic nutrition and survival. Famine is almost always caused by pre-existing conditions, such as drought, but its effects may be exacerbated by social factors, such as war. Particularly devastating examples include the Ethiopian famine and the Irish Potato Famine.
A flood is a natural disaster caused by too much rain or water in a location, and could be caused by many different sets of conditions. Floods can be caused by prolonged rainfall from a storm, including thunderstorms, rapid melting of large amounts of snow, or rivers which swell from excess precipitation upstream and cause widespread damage to areas downstream, or less frequently the bursting of man-made dams. A river which floods particularly often is the Huang He in China, and a particularly damaging flood was the Great Flood of 1993.
A forest fire is a natural disaster consisting of a fire which destroys a forested area, and can be a great danger to people who live in forests as well as wildlife. Forest fires are generally started by lightning, but also by human negligence or arson, and can burn thousands of square kilometers. An example of a severe forest fire is the Oakland Hills firestorm.
A hailstorm is a natural disaster where a thunderstorm produces a numerous amount of hailstones which damage the location in which they fall. Hailstorms can be especially devastating to farm fields, ruining crops and damaging equipment. A particularly damaging hailstorm hit Munich, Germany on August 31, 1986, felling thousands of trees and causing millions of dollars in insurance claims.
A heat wave is a disaster characterized by heat which is considered extreme and unusual in the area in which it occurs. Heat waves are rare and require specific combinations of weather events to take place, and may include temperature inversions, katabatic winds, or other phenomena. The worst heat wave in recent history was the European Heat Wave of 2003.
A hurricane is a cyclonic storm system which forms over the oceans. It is caused by evaporated water which comes off of the ocean and becomes a storm. The Coriolis Effect causes the storms to spin, and a hurricane is declared when this spinning mass of storms attains a wind speed greater than 74mph. In different parts of the world hurricanes are known as cyclones or typhoons. The former occur in the Indian Ocean, while the latter occur in the Eastern Pacific Ocean. The most damaging hurricane ever was Hurricane Andrew, which hit southern Florida in 1992.
An ice storm is a particular weather event in which precipitation falls as rain, due to atmosphere conditions, but the in an area in which the temperature is below the freezing point of water. The rain falls to the ground, and immediately turns to ice, accumulating in that fashion. A heavy ice storm can cause large accumulations of ice cause trees to fall over or lose branches, and power lines to snap. The worst recent ice storm was the 1998 Ice Storm that struck eastern Canada and areas of the US northeast.
A Lahar is a type of natural disaster closely related to a volcanic eruption, and involves a large amount of material, including mud, rock, and ash sliding down the side of the volcano at a rapid pace. These flows can destroy entire towns in seconds and kill thousands of people. The Tangiwai disaster is an excellent example, as is the one which killed an estimated 23,000 people in Armero, Colombia, during the 1985 eruption of Nevado del Ruiz.
Landslides and Mudslides
A landslide is a disaster closely related to an avalanche, but instead of occurring with snow, it occurs involving actual elements of the ground, including rocks, trees, parts of houses, and anything else which may happen to be swept up. Landslides can be caused by earthquakes, volcanic eruptions, or general instability in the surrounding land. Mudslides, or mud flows, are a special case of landslides, in which heavy rainfall causes loose soil on steep terrain to collapse and slide downwards (see also Lahar); these occur with some regularity in parts of California after periods of heavy rain.
A localized depression in the surface topography, usually caused by the collapse of a subterranean structure, such as a cave. Although rare, large sinkholes that develop suddenly in populated areas can lead to the collapse of buildings and other structures.
A tornado is a natural disaster resulting from a thunderstorm. Tornadoes are violent currents of wind which can blow at up to 318mph. Tornadoes can occur one at a time, or can occur in large tornado outbreaks along a squall line. The worst tornado ever recorded in terms of wind speed was the tornado which swept through Moore, Oklahoma on May 3, 1999. This tornado has wind speeds of 318mph and was the strongest ever recorded.
A tsunami is a giant wave of water which rolls into the shore of an area with a height of over 15 m (50 ft). It comes from Japanese words meaning harbor and wave. Tsunami can be caused by undersea earthquakes as in the 2004 Indian Ocean Earthquake, or by landslides such as the one which occurred at Lituya Bay, Alaska. The tsunami generated by the 2004 Indian Ocean Earthquake currently ranks as the deadliest tsunami in recorded history. The highest Tsunami ever recorded was estimated to be 85m (278 ft.) high. It appeared on April 24th, off Ishigaki Island, Japan.
This natural disaster is caused by the eruption of a volcano, and eruptions come in many forms. They range from daily small eruptions which occur in places ;like Kilauea, in Hawaii, or extremely infrequent supervolcano eruptions in places like Lake Toba. Greatest Volcanic EXPLOSION occurred when Krakatoa in Indonesia blew up in 1883, hurling rocks 55km (34 miles) in the air! The explosion was heard in Australia and generated a 40m. (131 ft.) high Tsunami; 36,000 people died. The greatest volcanic ERUPTION was of Mt. Tambora on Sumbawa, Indonesia in 1815 which threw up more than 100 cubic km. (24cu. miles) of ash. The island was lowered by 1250m (4100 ft.); 92,000 people died.
Extreme natural disasters
An ice age is a geologic period, but could also be viewed in the light of a catastrophic natural disaster, since in an ice age, the climate all over the world would change and places which were once considered habitable would then be too cold in permanently inhabit. A side effect of an ice age could possibly be a famine, caused by a worldwide drought.
An impact event is a natural disaster in which an extraterrestrial piece of rock or other material collides with the Earth. The exact consequences of a direct Earth impact would vary greatly with size of the colliding object, although in cases of medium to large impacts short-term climate change and a general failure of agriculture.
A solar flare is a phenomenon where the sun suddenly releases a great amount of solar radiation, much more than normal. It is theorized that these releases of radiation could cause a widespread failure of communications technology across the globe. The exact implications of such a failure are unknown.
A supervolcano is a eruption which is thousands of times more massive than a normal eruption, the lower threshold for an eruption being declared that of a supervolcano is that such an eruption must expel at least 1000 cubic kilometers of material. The last eruption of this magnitude occurred over 75,000 years ago at Lake Toba. If such an eruption were to occur today, a wholesale general die-off of both animals and humans would occur, as well as a significant short-term climate change.
- Natural disasters by country
- Civil defense
- Disaster relief
- Emergency preparedness
- List of disasters
- Weather disasters
- Abbott, Peter Leon. Natural Disasters, McGraw-Hill Science/Engineering/Math, 3 edition (2001)
- Bankoff, Greg, George Frerks and Dorothea Hilhorst. 2004. Mapping Vulnerability.Sterling: Earthscan.
- Blaikie, Piers, Terry Cannon, Ian Davis, and Ben Wisner. 1994. "At Risk: Natural hazards, people's vulnerability, and disasters." New York, NY: Routledge.
- Kreps, G.A. Ed. 1986. Social Structure and Disaster. Newark: University of Delaware Press.
- Mileti, Dennis. Disasters by Design: A Reassessment of Natural Hazards in the United States, National Academies Press (1999).
- Oliver-Smith, Anthony and Susannah M. Hoffman. The Angry Earth: Disaster in Anthropological Perspective, Routledge, 1st edition (1999).
- Wade, Nicholas. The New York Times Book of Natural Disasters, The Lyons Press, 1st edition (2001)
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