A rope tornado in its dissipatingstage, Tecumseh, Oklahoma.

A daytime wildfire in California.

Natural disasterFrom Wikipedia, the free encyclopedia

A natural disaster is a major adverse event resulting fromnatural processes of the Earth; examples include floods, volcaniceruptions, earthquakes, tsunamis, and other geologic processes.A natural disaster can cause loss of life or property damage, andtypically leaves some economic damage in its wake, the severityof which depends on the affected population's resilience, orability to recover.[1]

An adverse event will not rise to the level of a disaster if it occursin an area without vulnerable population.[2][3][4] In a vulnerablearea, however, such as San Francisco, an earthquake can havedisastrous consequences and leave lasting damage, requiringyears to repair.

In 2012, there were 905 natural disasters worldwide, 93% ofwhich were weather-related disasters. Overall costs were US$170billion and insured losses $70 billion. 2012 was a moderate year.45% were meteorological (storms), 36% were hydrological(floods), 12% were climatological (heat waves, cold waves,droughts, wildfires) and 7% were geophysical events(earthquakes and volcanic eruptions). Between 1980 and 2011geophysical events accounted for 14% of all naturalcatastrophes.[5]

Contents

1 Avalanches2 Earthquakes3 Volcanic eruptions4 Hydrological disasters

4.1 Floods4.2 Limnic eruptions4.3 Tsunami

5 Meteorological disasters5.1 Blizzards5.2 Cyclonic storms

5.2.1 Tropical Cyclones5.2.2 Extratropical Cyclones

5.3 Droughts5.4 Hailstorms5.5 Heat waves

A powder snow avalanche

The 1693 Sicily earthquake

5.6 Tornadoes6 Wildfires7 Health disasters

7.1 Epidemics8 Space disasters

8.1 Impact events8.2 Solar flare8.3 Gamma-ray burst

9 Protection by international law10 See also11 References12 External links

Avalanches

During World War I, an estimated 40,000 to 80,000 soldiers diedas a result of avalanches during the mountain campaign in theAlps at the Austrian-Italian front, many of which were caused byartillery fire.[6]

Earthquakes

An earthquake is the result of a sudden release of energy in theEarth's crust that creates seismic waves. At the Earth's surface,earthquakes manifest themselves by vibration, shaking andsometimes displacement of the ground. The vibrations may varyin magnitude. Earthquakes are caused mostly by slippage withingeological faults, but also by other events such as volcanic activity,landslides, mine blasts, and nuclear tests. The underground point oforigin of the earthquake is called the focus. The point directly abovethe focus on the surface is called the epicenter. Earthquakes bythemselves rarely kill people or wildlife. It is usually the secondaryevents that they trigger, such as building collapse, fires, tsunamis(seismic sea waves) and volcanoes, that are actually the humandisaster. Many of these could possibly be avoided by betterconstruction, safety systems, early warning and planning. Some ofthe most significant earthquakes in recent times include:

The 2004 Indian Ocean earthquake, the third largestearthquake recorded in history, registering a moment magnitude of 9.1-9.3. The huge tsunamistriggered by this earthquake killed at least 229,000 people.The 2011 Tōhoku earthquake and tsunami registered a moment magnitude of 9.0. The earthquakeand tsunami killed 15,889 and injured 6,152. 2,609 were still missing as of 2014.

Artist's impression of the volcaniceruptions that formed the DeccanTraps in India.

The 8.8 magnitude February 27, 2010 Chile earthquake and tsunami cost 525 lives.[7]

The 7.9 magnitude May 12, 2008 Sichuan earthquake in Sichuan Province, China. Death toll atover 61,150 as of May 27, 2008.The 7.7 magnitude 2006 Pangandaran earthquake and tsunami.The 6.9 magnitude 2005 Azad Jammu & Kashmir and KPK province Earthquake, which killed orinjured above 75,000 people in Pakistan.

Volcanic eruptions

Volcanoes can cause widespread destruction and consequentdisaster in several ways. The effects include the volcaniceruption itself that may cause harm following the explosion ofthe volcano or the fall of rock. Second, lava may be producedduring the eruption of a volcano. As it leaves the volcano, thelava destroys many buildings and plants it encounters. Third,volcanic ash generally meaning the cooled ash - may form acloud, and settle thickly in nearby locations. When mixed withwater this forms a concrete-like material. In sufficient quantityash may cause roofs to collapse under its weight but even smallquantities will harm humans if inhaled. Since the ash has theconsistency of ground glass it causes abrasion damage to movingparts such as engines. The main killer of humans in theimmediate surroundings of a volcanic eruption is the pyroclasticflows, which consist of a cloud of hot volcanic ash which builds up in the air above the volcano andrushes down the slopes when the eruption no longer supports the lifting of the gases. It is believed thatPompeii was destroyed by a pyroclastic flow. A lahar is a volcanic mudflow or landslide. The 1953Tangiwai disaster was caused by a lahar, as was the 1985 Armero tragedy in which the town of Armerowas buried and an estimated 23,000 people were killed .

A specific type of volcano is the supervolcano. According to the Toba catastrophe theory 75,000 to80,000 years ago a super volcanic event at Lake Toba reduced the human population to 10,000 or even1,000 breeding pairs creating a bottleneck in human evolution.[8] It also killed three quarters of all plantlife in the northern hemisphere. The main danger from a supervolcano is the immense cloud of ashwhich has a disastrous global effect on climate and temperature for many years.

Hydrological disasters

It is a violent, sudden and destructive change either in quality of earth's water or in distribution ormovement of water on land below the surface or in atmosphere.

Floods

A flood is an overflow of an expanse of water that submerges land.[9] The EU Floods directive defines aflood as a temporary covering by water of land not normally covered by water.[10] In the sense of"flowing water", the word may also be applied to the inflow of the tide. Flooding may result from thevolume of water within a body of water, such as a river or lake, which overflows or breaks levees, withthe result that some of the water escapes its usual boundaries.[11] While the size of a lake or other body

The Limpopo River, in southernMozambique, during the 2000Mozambique flood

of water will vary with seasonal changes in precipitation and snow melt, it is not a significant floodunless the water covers land used by man like a village, city or other inhabited area, roads, expanses offarmland, etc.

Some of the most notable floods include:

The Johnstown Flood of 1889 where over 2200 people losttheir lives when the South Fork Dam holding back LakeConemaugh broke.The Huang He (Yellow River) in China floods particularlyoften. The Great Flood of 1931 caused between 800,000and 4,000,000 deaths.The Great Flood of 1993 was one of the most costly floodsin United States history.The North Sea flood of 1953 which killed 2251 people inthe Netherlands and eastern EnglandThe 1998 Yangtze River Floods, in China, left 14 million people homeless.The 2000 Mozambique flood covered much of the country for three weeks, resulting in thousandsof deaths, and leaving the country devastated for years afterward.The 2005 Mumbai floods which killed 1094 people.The 2010 Pakistan floods directly affected about 20 million people, mostly by dispolacement,destruction of crops, infrastructure, property and livelihood, with a death toll of close to 2,000.The 2014 India–Pakistan floods

Tropical cyclones can result in extensive flooding and storm surge, as happened with:

Bhola Cyclone, which struck East Pakistan (now Bangladesh) in 1970,Typhoon Nina, which struck China in 1975,Hurricane Katrina, which struck New Orleans, Louisiana in 2005, andCyclone Yasi, which struck Australia in 2011

Limnic eruptions

A limnic eruption occurs when a gas, usually CO2, suddenly erupts from deep lake water, posing thethreat of suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in thelake as the rising gas displaces water. Scientists believe landslides, volcanic activity, or explosions cantrigger such an eruption. To date, only two limnic eruptions have been observed and recorded:

In 1984, in Cameroon, a limnic eruption in Lake Monoun caused the deaths of 37 nearbyresidents.At nearby Lake Nyos in 1986 a much larger eruption killed between 1,700 and 1,800 people byasphyxiation.

A cow suffocated bygases from Lake Nyosafter a limnic eruption

Young steer after a blizzard, March1966

Tsunami

Tsunamis can be caused by undersea earthquakes as the one caused by the 2004 Indian OceanEarthquake, or by landslides such as the one which occurred at Lituya Bay, Alaska.

The 2004 Indian Ocean Earthquake created the Boxing Day Tsunami.On March 11, 2011, a tsunami occurred near Fukushima, Japan and spread through the Pacific.

Meteorological disasters

Blizzards

Blizzards are severe winter storms characterized by heavy snow and strongwinds. When high winds stir up snow that has already fallen, it is known asa ground blizzard. Blizzards can impact local economic activities, especiallyin regions where snowfall is rare.

Significant blizzards include:

The Great Blizzard of 1888 in the United States in which many tonsof wheat crops were destroyed.The 2008 Afghanistan blizzardThe North American blizzard of 1947The 1972 Iran blizzard resulted in approximately 4,000 deaths andlasted for 5 to 7 days.

Cyclonic storms

Tropical Cyclones

Cyclone, tropical cyclone, hurricane, and typhoon are differentnames for the same phenomenon a cyclonic storm system thatforms over the oceans. The deadliest hurricane ever was the 1970Bhola cyclone; the deadliest Atlantic hurricane was the GreatHurricane of 1780 which devastated Martinique, St. Eustatiusand Barbados. Another notable hurricane is Hurricane Katrinawhich devastated the Gulf Coast of the United States in 2005.

Extratropical Cyclones

Extratropical cyclones, sometimes called mid-latitude cyclones, are a group of cyclones defined assynoptic scale low pressure weather systems that occur in the middle latitudes of the Earth (outside thetropics) not having tropical characteristics, and are connected with fronts and horizontal gradients intemperature and dew point otherwise known as "baroclinic zones". As with tropical cyclones, they areknown by different names in different regions (Nor'easter, Pacific Northwest windstorms, Europeanwindstorm, East Asian-northwest Pacific storms, Sudestada and Australian east coast cyclones). Themost intense extratropical cyclones cause widespread disruption and damage to society, such as the

Hurricane Katrina

Affected areas in the western Sahelbelt during the 2012 drought.

storm surge of the North Sea flood of 1953 which killed 2251 people in the Netherlands and easternEngland, the Great Storm of 1987 which devastated southern England and France and the ColumbusDay Storm of 1962 which struck the Pacific Northwest.

Droughts

Drought is unusual dryness of soil, resulting in crop failure and shortage of water for other uses, causedby significantly lower rainfall than average over a prolonged period. Hot dry winds, high temperaturesand consequent evaporation of moisture from the ground can contribute to conditions of drought.

Well-known historical droughts include:

1900 India killing between 250,000 to 3.25 million.1921–22 Soviet Union in which over 5 million perishedfrom starvation due to drought1928–30 Northwest China resulting in over 3 milliondeaths by famine.1936 and 1941 Sichuan Province China resulting in 5million and 2.5 million deaths respectively.The 1997–2009 Millenium Drought in Australian led to awater supply crisis across much of the country. As a resultmany desalination plants were built for the first time (seelist).In 2006, Sichuan Province China experienced its worstdrought in modern times with nearly 8 million people andover 7 million cattle facing water shortages.12-year drought that was devastating southwest WesternAustralia, southeast South Australia, Victoria and northernTasmania was "very severe and without historicalprecedent".In 2011, the State of Texas lived under a droughtemergency declaration for the entire calendar year. Thedrought caused the Bastrop fires.

Hailstorms

Hailstorms are falls of rain drops that arrive as ice, rather than melting before they hit the ground. Aparticularly damaging hailstorm hit Munich, Germany, on July 12, 1984, causing about 2 billion dollarsin insurance claims.

Heat waves

A heat wave is a period of unusually and excessively hot weather. The worst heat wave in recent historywas the European Heat Wave of 2003.

A large hailstone, about 6 cm (2.4 in)in diameter

An exceptionally clearly developedsingle-cell Cumulonimbus incus Bigdisplaying the classic anvil shape;associated gusts may occur from thedirect proximity to several times theheight of the cloud.

A summer heat wave in Victoria, Australia, created conditionswhich fuelled the massive bushfires in 2009. Melbourneexperienced three days in a row of temperatures exceeding 40°C(104°F) with some regional areas sweltering through muchhigher temperatures. The bushfires, collectively known as "BlackSaturday", were partly the act of arsonists.

The 2010 Northern Hemisphere summer resulted in severe heatwaves, which killed over 2,000 people. It resulted in hundreds ofwildfires which causing widespread air pollution, and burnedthousands of square miles of forest.

Heat waves can occur in the ocean as well as on land with significant effects (often on a large scale) e.g.coral bleaching.

Tornadoes

A tornado is a violent, dangerous, rotating column of air that is incontact with both the surface of the earth and a cumulonimbuscloud or, in rare cases, the base of a cumulus cloud. It is alsoreferred to as a twister or a cyclone,[12] although the wordcyclone is used in meteorology in a wider sense, to refer to anyclosed low pressure circulation. Tornadoes come in many shapesand sizes, but are typically in the form of a visible condensationfunnel, whose narrow end touches the earth and is often encircledby a cloud of debris and dust. Most tornadoes have wind speedsless than 110 miles per hour (177 km/h), are approximately 250feet (80 m) across, and travel a few miles (several kilometers)before dissipating. The most extreme tornadoes can attain windspeeds of more than 300 mph (480 km/h), stretch more than twomiles (3 km) across, and stay on the ground for dozens of miles(perhaps more than 100 km).[13][14][15]

Well-known historical tornadoes include:

The Tri-State Tornado of 1925, which killed over 600 people in the United States;The Daulatpur-Saturia Tornado of 1989, which killed roughly 1,300 people in Bangladesh.

Wildfires

Wildfires are large fires which often start in wildland areas. Common causes include lightning anddrought but wildfires may also be started by human negligence or arson. They can spread to populatedareas and can thus be a threat to humans and property, as well as wildlife.

Notable cases of wildfires were the 1871 Peshtigo Fire in the United States, which killed at least 1700people, and the 2009 Victorian bushfires in Australia.

Health disasters

The A H5N1 virus, which causesAvian influenza

Fallen trees caused by theTunguska meteoroid of theTunguska event in June 1908.

Epidemics

An epidemic is an outbreak of a contractible disease that spreadsthrough a human population. A pandemic is an epidemic whosespread is global. There have been many epidemics throughouthistory, such as the Black Death. In the last hundred years,significant pandemics include:

The 1918 Spanish flu pandemic, killing an estimated 50million people worldwideThe 1957–58 Asian flu pandemic, which killed anestimated 1 million peopleThe 1968–69 Hong Kong water flu pandemicThe 2002-3 SARS pandemicThe AIDS pandemic, beginning in 1959The H1N1 Influenza (Swine Flu) Pandemic 2009–2010

Other diseases that spread more slowly, but are still considered to be global health emergencies by theWHO, include:

XDR TB, a strain of tuberculosis that is extensively resistant to drug treatmentsMalaria, which kills an estimated 1.6 million people each yearEbola hemorrhagic fever, which has claimed hundreds of victims in Africa in several outbreaks

Space disasters

Impact events

One of the largest impact events in modern times was the Tunguskaevent in June 1908.

Solar flare

A solar flare is a phenomenon where the sun suddenly releases agreat amount of solar radiation, much more than normal. Someknown solar flares include:

An X20 event on August 16, 1989[16]

A similar flare on April 2, 2001[16]

The most powerful flare ever recorded, on November 4, 2003, estimated at between X40 and

X45[17]

The most powerful flare in the past 500 years is believed to have occurred in September 1859[18]

Gamma-ray burst

Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosionsthat have been observed in distant galaxies. They are the brightest electromagnetic events known tooccur in the universe.[19] Bursts can last from ten milliseconds to several minutes. The initial burst isusually followed by a longer-lived "afterglow" emitted at longer wavelengths (X-ray, ultraviolet, optical,infrared, microwave and radio).

All the bursts astronomers have recorded so far have come from distant galaxies and have been harmlessto Earth, but if one occurred within our galaxy and were aimed straight at us, the effects could bedevastating. Currently orbiting satellites detect an average of about one gamma-ray burst per day. Theclosest known GRB so far was GRB 031203.[20]

Protection by international law

International law, for example Geneva Conventions defines International Red Cross and Red CrescentMovement the Convention on the Rights of Persons with Disabilities, requires that "States shall take, inaccordance with their obligations under international law, including international humanitarian law andinternational human rights law, all necessary measures to ensure the protection and safety of personswith disabilities in situations of risk, including the occurrence of natural disaster."[21] And further UnitedNations Office for the Coordination of Humanitarian Affairs is formed by General Assembly Resolution44/182. People displaced due to natural disasters are currently protected under international law(Guiding Principles of International Displacement, Campala Convention of 2009).[22]

See also

Act of GodEffects of climate change on humansEmergency management

Civil defenseDisaster Risk Reduction

Environmental disasterList of environmental disasters

Environmental emergencyGamma ray burstList of countries by natural disaster riskList of natural disasters by death tollProperty insuranceSurvivalismWorld Conference on Disaster Reduction

References

1. ^ G. Bankoff, G. Frerks, D. Hilhorst (eds.) (2003). Mapping Vulnerability: Disasters, Development andPeople. ISBN 1-85383-964-7.

2. ^ Luis Flores Ballesteros. "What determines a disaster?" 54 Pesos Sep 2008:54 Pesos 11 Sep 2008.

<http://54pesos.org/2008/09/11/what-determines-a-disaster/>3. ^ D. Alexander (2002). Principles of Emergency planning and Management. Harpended: Terra publishing.

ISBN 1-903544-10-6.4. ^ B. Wisner, P. Blaikie, T. Cannon, and I. Davis (2004). At Risk - Natural hazards, people's vulnerability and

disasters. Wiltshire: Routledge. ISBN 0-415-25216-4.5. ^ Natural Catastrophes in 2012 Dominated by U.S. Weather Extremes (http://www.worldwatch.org/natural-

catastrophes-2012-dominated-us-weather-extremes-0) Worldwatch Institute May 29, 20136. ^ Lee Davis (2008). "Natural Disasters (http://books.google.com/books?

id=CRzMOYIuLJEC&pg=&dq&hl=en#v=onepage&q=&f=false)". Infobase Publishing. p.7. ISBN 0-8160-7000-8

7. ^ ^ "USGS Earthquake Details". United States Geological Survey.http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010tfan/. Retrieved February 27, 2010

8. ^ Gibbons, Ann (19 January 2010). "Human Ancestors Were an Endangered Species"(http://sciencenow.sciencemag.org/cgi/content/full/2010/119/2). ScienceNow.

9. ^ MSN Encarta Dictionary. Flood.(http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861612277) Retrieved on2006-12-28. Archived (http://www.webcitation.org/query?id=1257023547055729) 2009-10-31.

10. ^ Directive 2007/60/EC Chapter 1 Article2 (http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:288:0027:0034:EN:PDF)

11. ^ Glossary of Meteorology (June 2000). Flood. (http://amsglossary.allenpress.com/glossary/search?id=flood1) Retrieved on 2009-01-09.

12. ^ merriam-webster.com (http://www.merriam-webster.com/dictionary/cyclone)13. ^ Wurman, Joshua (2008-08-29). "Doppler On Wheels" (http://cswr.org/dow/DOW.htm). Center for Severe

Weather Research. Retrieved 2009-12-13.14. ^ "Hallam Nebraska Tornado" (http://www.crh.noaa.gov/oax/archive/hallam/hallam.php). National Weather

Service. National Oceanic and Atmospheric Administration. 2005-10-02. Retrieved 2009-11-15.15. ^ Roger Edwards (2006-04-04). "The Online Tornado FAQ" (http://www.spc.ncep.noaa.gov/faq/tornado/).

National Weather Service. National Oceanic and Atmospheric Administration. Retrieved 2006-09-08.

16. ^ a b "Sun Unleashes Record Superflare, Earth Dodges Solar Bullet"(http://www.sciencedaily.com/releases/2001/04/010404081121.htm). ScienceDaily. April 4, 2011. Retrieved2011-08-27.

17. ^ "Biggest Solar Flare ever recorded"(http://www.nasca.org.uk/Strange_Maps/solar/Solar_Flare/solar_flare.html). National Association forScientific and Cultural Appreciation. 2004. Retrieved 2011-08-27.

18. ^ "A Super Solar Flare" (http://science.nasa.gov/science-news/science-at-nasa/2008/06may_carringtonflare/).NASA. May 6, 2008. Retrieved 2011-08-27.

19. ^ "Gamma Rays" (http://missionscience.nasa.gov/ems/12_gammarays.html). NASA.20. ^ Chandra Contributes to ESA's Integral Detection of Closest Gamma-Ray Burst

(http://chandra.harvard.edu/press/04_releases/press_080404.html). chandra.harvard.edu (2004-08-04)21. ^ Article 11 of the Convention on the Rights of Persons with Disabilities22. ^ Terminski, Bogumil, Towards Recognition and Protection of Forced Environmental Migrants in the Public

International Law: Refugee or IDPs Umbrella (December 1, 2011). Policy Studies Organization (PSO)Summit, December 2011.

Wikiquote has quotationsrelated to: Natural disasters

External links

"Natural Disasters News"(http://www.naturaldisastersnews.net). Ubyrisk.Worldwide news site focused on natural disasters,mitigation and climate changes news"Global Risk Identification Program (GRIP)" (http://www.gripweb.org). GRIP."BioCaster Global Health Monitor" (http://born.nii.ac.jp/). National Institute of Informatics (NII)."World Bank's Hazard Risk Management" (http://go.worldbank.org/BCQUXRXOW0). WorldBank."Disaster News Network" (http://www.disasternews.net/). Retrieved 2006-11-05. US news sitefocused on disaster-related news."EM-DAT International Disaster Database" (http://www.em-dat.net). Retrieved 2006-11-05.Includes country profiles, disaster profiles and a disaster list."Global Disaster Alert and Coordination System" (http://www.gdacs.org). European Commissionand United Nations website initiative."Natural Disaster and Extreme Weather. Searchable Information Center"(http://site.ebrary.com/lib/disaster/home.action). Ebrary.

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