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Earth Sciences: Natural Disasters and Hazards, directory for Earth... healthysense.com | Introduction To Natural Disasters And Other Disasters mentalhelp.net | Natural Disasters Reciprocal Links ssrsi.org |
For the professional wrestling tag team, see The Natural Disasters.
A natural disaster is the effect of a natural hazard (e.g. flood,(tornado) volcano eruption, earthquake, or landslide) that affects the environment, and leads to financial, environmental and/or human losses. The resulting loss depends on the capacity of the population to support or resist the disaster, and their resilience.[1] This understanding is concentrated in the formulation: "disasters occur when hazards meet vulnerability."[2] A natural hazard will hence never result in a natural disaster in areas without vulnerability, e.g. strong earthquakes in uninhabited areas. The term natural has consequently been disputed because the events simply are not hazards or disasters without human involvement.[3]
Natural hazardsMain article: Natural hazard A natural hazard is a threat of an event that will have a negative effect on people or the environment. Many natural hazards are related, e.g. earthquakes can result in tsunamis, drought can lead directly to famine and disease. A concrete example of the division between hazard and disaster is that the 1906 San Francisco earthquake was a disaster, whereas earthquakes are a hazard. Hazards are consequently relating to a future occurrence and disasters to past or current occurrences. Natural disastersMain articles: disaster and list of deadliest natural disasters Land movement disastersAvalanches Notable avalanches include:
EarthquakesAn Earthquake is a sudden shake of the Earth's crust.The vibrations may vary in magnitude. The earthquake has point of origin underground called the "focus". The point directly above the focus on the surface is called the"epicentre". Earthquakes by themselves rarely kill people or wildlife. It is usually the secondary events that they trigger, such as building collapse, fires, tsunamis (seismic sea waves) and volcanoes, that are actually the human disaster. As many of these could be avoided by better construction, safety systems, early warning and evacuation planning, the term unnatural disaster is not unwarranted. Earthquakes are caused by the discharge of accumulated along geologic faults. Main article: List of earthquakes Some of the most significant earthquakes in recent times include:
LaharsA lahar is a volcanic mudflow or landslide. The 1953 Tangiwai disaster was caused by a lahar, as was the 1985 Armero tragedy in which the town of Armero was buried and an estimated 23,000 people were killed Landslides and MudflowsThese occur with some regularity in parts of California after periods of heavy rain. Volcanic eruptionsMain article: Types of volcanic eruptions
Water disastersFloodsMain article: List of floods  Some of the most notable floods include:
Tropical cyclones can result in extensive flooding and storm surge, as happened with:
Limnic eruptions A limnic eruption occurs when CO2 suddenly erupts from deep lake water, posing the threat of suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists believe landslides, volcanic activity, or explosions can trigger such an eruption.Till date, only two limnic eruptions have been observed and recorded:
Tsunamis Tsunamis can be caused by undersea earthquakes as the one caused in Ao Nang, Thailand by the 2004 Indian Ocean Earthquake, or by landslides such as the one which occurred at Lituya Bay, Alaska in.
Weather disastersMain article: Weather disasters  BlizzardsSignificant blizzards in the United States include:
Cyclonic stormsMain articles: tropical cyclone and cyclone Cyclone, tropical cyclone, hurricane, and typhoon are different names for the same phenomenon a cyclonic storm system that forms over the oceans. The deadliest hurricane ever was the 1970 Bhola cyclone the deadliest Atlantic hurricane was the Great Hurricane of 1780 which devastated Martinique St. Eustatius and Barbados. Another notable hurricane is Hurricane Katrina which devastated the Gulf Coast of the United States in 2005. DroughtsWell-known historical droughts include:
HailstormsHailstorms (AKA hailstones) are rain drops that have formed together into ice. A particularly damaging hailstorm hit Munich, Germany on August 31, 1986, felling thousands of trees and causing millions of dollars in insurance claims. Heat wavesThe worst heat wave in recent history was the European Heat Wave of 2003. The heat wave in Victoria Australia caused the massive bushfires in 2009, Melbourne experienced 3 days in a row of temperatures exceeding 43°C. TornadoesMain article: tornado Different Types of Tornadoes Supercell Tornadoes Main article: Supercell Some of the most violent tornadoes develop from supercell thunderstorms. A supercell thunderstorm is a long-lived thunderstorm possessing within its structure a continuously rotating updraft of air. These storms have the greatest tendency to produce tornadoes, some of the huge wedge shape. The supercell thunderstorm has a low-hanging, rotating layer of cloud known as a “wall cloud.” It looks somewhat like a layer of a layer cake that hangs below the broader cloud base. One side of the wall cloud is often rain-free, while the other is neighbored by dense shafts of rain. The rotating updraft of the supercell is seen on radar as a “mesocyclone.” The tornadoes that accompany supercell thunderstorms are more likely to remain in contact with the ground for long periods of time—an hour or more—than other tornadoes, and are more likely to be violent, with winds exceeding 200 mph. Landspout Main article: landspout Generally weaker than a supercell tornado, a landspout is not associated with a wall cloud or mesocyclone. It may be observed beneath cumulonimbus or towering cumulus clouds and is the land equivalent of a waterspout. It often forms along the leading edge of rain-cooled downdraft air emanating from a thunderstorm, known as a “gust front.” Gustnado Main article: Gustnado Weak and usually short-lived, a gustnado forms along the gust front of a thunderstorm, appearing as a temporary dust whirl or debris cloud. There may be no apparent connection to or circulation in the cloud aloft. These appear like dust devils. Waterspout A waterspout is a tornado over water. A few form from supercell thunderstorms, but many form from weak thunderstorms or rapidly growing cumulus clouds. Waterspouts are usually less intense and causes far less damage. Rarely more than fifty yards wide, it forms over warm tropical ocean waters, although its funnel is made of freshwater droplets condensed from water vapor from condensation - not saltwater from the ocean. Waterspouts usually dissipate upon reaching land. The following are tornado-like circulations Dust Devils Main article: dust devil Dry, hot, clear days on the desert or over dry land can bring about dust devils. Generally forming in the hot sun during the late morning or early afternoon hours, these mostly harmless whirlwinds are triggered by light desert breezes that create a swirling plume of dust with speeds rarely over 70 mph. These differ from tornadoes in that they are not associated with a thunderstorm (or any cloud), and are usually weaker than the weakest tornado. Typically, the life cycle of a dust devil is a few minutes or less, although they can last much longer. Although usually harmless, they have been known to cause minor damage. They can blow vehicles off the road and could damage your eyes by blowing dust into them. Firewhirls Main article: fire whirl Sometimes the intense heat created by a major forest fire or volcanic eruption can create what is known as a firewhirl, a tornado-like rotating column of smoke and/or fire. This happens when the fire updraft concentrates some initial weak whirl or eddy in the wind. Winds associated with firewhirls have been estimated at over 100 mph. They are sometimes called fire tornadoes, fire devils, or even firenadoes.[4] FireMain article: List of forest fires Wildfires are an uncontrolled fire burning in wildland areas. Common causes include lightning and drought but wildfires may also be started by human negligence or arson. They can be a threat to those in rural areas and also wildlife. A notable case of wildfire was the 2009 Victorian bushfires in Australia. Health and diseasesEpidemicMain article: List of epidemics  An epidemic is an outbreak of a contractible disease that spreads at a rapid rate through a human population. A pandemic is an epidemic whose spread is global. There have been many epidemics throughout history, such as Black Death. In the last hundred years, significant pandemics include:
Other diseases that spread more slowly, but are still considered to be global health emergencies by the WHO include:
FamineMain article: List of famines In modern times, famine has hit Sub-Saharan Africa the hardest, although the number of victims of modern famines is much smaller than the number of people killed by the Asian famines of the 20th century. Space Gamma ray burstsMain article: gamma ray burst Impact eventsMain article: impact event One of the largest impact events in modern times was the Tunguska event in June, 1908. Solar flaresMain article: solar flare A solar flare is a phenomenon where the sun suddenly releases a great amount of solar radiation, much more than normal. Some known solar flares include:
Supernovae and hypernovaeFuture of natural disastersThe United Kingdom based charity Oxfam publicly stated that the number of people hit by climate-related disasters is expected to rise by about 50%, to reach 375 million a year by 2015.[5] InsuranceNatural disasters play a major role in the insurance industry, which pays for certain damages arising from hurricanes, wildfires, and other catastrophes. Large reinsurance companies are particularly involved.[6] See alsoReferences
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