Luis Blog 2016: Natural Disasters

Natural Disasters

Planet Earth through its geological history and since its formation has evolved in different ways. Many of these processes of transformation and change occur in a drastic and cataclysmic way. Actually, these change continue and manifest themselves in many ways. Natural disasters are part of these changes that happen in the Earth, this term is defined as extreme and sudden events caused by environmental factors that injure people and damage property. These disasters can be sub divided into two groups: the natural disasters related with atmospheric phenomena and natural disasters caused by geological force and processes. Therefore, these are the result of external and internal processes that happen in the planet.

Natural disasters produced by atmospheric phenomena are part of these external processes of Earth. The external process that occurs in the atmosphere, specifically in troposphere (one of the atmosphere’s layers), changes every day, modifies the climate and the weather of a particular region of the world. This means that these phenomena occurs in any part of the world. Natural disasters related with external process in the Earth’s atmosphere are cyclonic storms like tropical storms and hurricanes, winter storms like blizzards, droughts, heat waves, floods by heavy rains, electrical storms, hailstorms and tornadoes. Some major meteorological disasters can generate others, for example, hurricanes (systems that forms over the ocean), produce floods by heavy rains (overflow of water that submerges land), electrical storms (lightning and thunderstorms), hailstorms (drops that arrive as ice) and tornadoes (a violent rotating column of air that is in contact with surface and a cloud) inland. Heat waves (a period of excessively hot weather) and drought (unusual dryness of soil and water reservoirs) are associated together with the lack of rain in a large period of time. Also winter storms generate blizzards (heavy snow and strong cold wind) and others extreme events related with lower temperatures.

Also, natural disasters can be classified by geological disasters, these that happen by internal processes of Earth. Tectonic forces generated inside the Earth created the mountains, produced volcanoes, generated earthquakes, and deformed rocks. The tectonic plates are pieces of the lithosphere (external layer of the Earth) that slide over the asthenosphere (part of the outermost portion of the Earth’s mantle that is below the lithosphere) being less dense. These process produces the geological disasters like earthquakes, tsunamis, volcanic eruptions, avalanches and mudslides and the opening of sinkholes. Earthquakes are originated by sudden release of energy in the Earth’s crust that creates seismic waves, tectonic plates generate this colliding with each other, separating from one another and rubbing each other. Tsunamis are a series of waves in a water body caused by the displacement of large volume of water that arrive to coastal areas, they can be caused by undersea earthquakes or volcanic eruptions. Volcanoes can generate destruction in many ways: the explosion can produce fall of rocks, lava can destroy everything in its path, including also the volcanic ash. Avalanches and mudslide can bury entire villages and can be produced by internal and external processes.

There are other natural disasters such as wildfires (large fires which starting wildland area and are caused by lightning, drought or human negligence), health disasters and space disasters. Health disasters are related with epidemics, outbreak of a contractible diseases that spreads through a human population, also it can be pandemic (spread globally). Space disasters are less common, an example of this are asteroid or meteorite impacts associated with major extinction events, and solar storms, events where the sun releases a great amount of radiation, although they are unlikely to cause direct injury, but can affect electric equipment.

All these natural disasters generate many human and materials losses. Around the planet there had been different natural disasters. In 2005 hurricane Katrina devastated the Gulf Coast of United States, being one of the most powerful hurricane of the world. As recently as in 2011 happened in Japan one of the most powerful earthquake followed by a devastating tsunami that produced thousands of human and material losses, including geological deformation. Other disasters related with diseases and natural events generate devastation in entire world. The majority of these disasters cannot be controlled by humans, some can only be forecasted, for these reasons all we can do is prepare as much as possible to face these natural processes and change of the planet on which we live.