There is talk of natural disasters to refer to major traumatic events for human society, the effects of which are linked to natural phenomena and even those derived from certain human activities, such as in the case of major industrial pollution.
The cost of natural disasters usually implies the numerous loss of life, human and animal, as well as the damage to entire ecosystems or human settlements of any kind. In this, natural phenomena are distinguished, which are isolated natural events, without traumatic consequences for human life, from disasters themselves. Broadly speaking, natural disasters can be classified according to the type of risk mechanisms they involve, namely:
- Mass movements. They involve large amounts of land in free movement.
- Atmospheric phenomena. They have to do with the environmental and/or climatic conditions, which is why they are often usual or customary phenomena, taken by exception to the extreme.
- Tectonic phenomena. Derived from the movement and rearrangement of the tectonic plates, or from chemical reactions that take place in the subsoil.
- Contaminations. They consist of spreading toxic or lethal agents in a specific area, without being able to contain them easily. Whether they are biological, chemical or industrial agents. (See: Pollution of water, soil, air )
- Spatial phenomena. Coming from outside the planet or involving forces of the stars.
- Fire. Destruction of plant life or urban areas under the effect of fire.
- River disasters. They concern the great bodies of water on the planet, such as oceans, lakes or rivers. They can be a consequence of climatic phenomena: floods due to extensive rains.
Examples of natural disasters
Meteor impacts . Fortunately, they are unusual in the fall of massive objects from space, whose impacts against the Earth’s surface would lead to the suspension of large clouds of matter in the atmosphere and other destructive phenomena leading to mass extinction. One of the most accepted theories about the extinction of dinosaurs (and 75% of life on earth) 65 million years ago, accuses the impact of a meteorite in Yucatan, Mexico.
Avalanches or avalanches , characterized by the abrupt displacement of large amounts of matter, down the slope of a mountain. Such matter can be snow, ice, stones, mud, dust, trees or a mixture of it. One of the deadliest avalanches in history took place on September 20, 2002 in Russia, when a melting glacier devastated the town of Ninji Karmadon in North Ossetia, killing 127 people.
Hurricanes, Cyclones or Typhoons are cyclical systems of stormy winds that form in the ocean and can rotate at more than 110 kilometers per hour, transporting huge rainy clouds and subjecting everything in their path to the force of their winds. The most destructive tropical cyclone of the 20th century was Hurricane Sandy, which in 2005 hit the Bahamas and the south American coast, leaving a trail of destruction and flooding in its wake that killed at least 1,833 people.
Big fires . Whether produced by the hand of man or as a result of other accidents and explosions, the uncontrollable action of fire in natural or urban areas is usually one of the most disastrous possible. The city of London, for example, suffered in 1666 a gigantic fire that lasted three full days and destroyed the medieval city center, leaving 80,000 people homeless.
Earthquakes and tremors . As a result of the movements of the Earth’s crust, they are usually unexpected and devastating, especially since they can cause volcanic eruptions or tsunamis once they have ended. In 2010, a 7.0 earthquake on the Richter scale occurred in Haiti, the effects of which on the already impoverished nation, along with the subsequent tsunami, killed more than 300,000 people.
Radioactive contamination , by spreading atomically unstable substances, whose main condition is to emit toxic particles into the environment, causing immediate damage, disease and long-term damage to all surrounding life forms. The accident at the Chernobyl nuclear reactor in the former Soviet Union is famous, the most serious of nuclear accidents in history. As a consequence, 600,000 people received lethal doses of radiation, 5 million lived in contaminated areas and 400,000 in areas that are currently uninhabitable.
Floods , usually the product of long periods of rain in poorly absorbent soils (such as deforested), are accumulations of water in uncontrollable volumes, submerging crops, villages and triggering other types of river disasters. The great flood suffered in Argentina by the population of Pergamino, in the province of Buenos Aires in April 1995, forced the evacuation of more than 13,000 people.
Tornadoes , like those often experienced in the southern part of the US, are the product of the collision of two air masses of different temperatures, formed from a storm and that can rotate around each other at high speeds , destroying everything in its path. The fastest in history (over 500kmph) was recorded in Moore, Oklahoma, in 1999.
Pandemias, o brotes de agentes microbióticos altamente infecciosos que escapan a todo tipo de cuarentena o control, pueden diezmar poblaciones enteras si no existe el apoyo científico apropiado. Tal fue el caso de la epidemia de Ébola en el occidente del continente africano entre 2014 y 2016, cuyo saldo oficial es de 11.323 muertes.
Las erupciones volcánicas, en las cuales el material químico encontrado por debajo de la corteza terrestre halla grietas o fisuras por las cuales escapar, arrojando gases, cenizas e incluso lava hirviente alrededor. Ha habido trágicas erupciones volcánicas en la historia, como la del Vesubio, volcán que en el año 79 d.C. sepultó por completo a la antigua ciudad romana de Pompeya, en la actual bahía de Nápoles.