We explain what natural disasters are, what their causes and consequences are. Also, its characteristics, classification and examples.
What are natural disasters?
Natural disasters are natural events that cause significant human or material losses. They are characterized by being generated by nature and seriously impacting societies. Some natural disasters are earthquakes, volcanic eruptions and tsunamis.
Another characteristic of natural disasters is that Humans can’t do anything to stop them.and they cannot influence to reduce its intensity either. The only measures that societies can take against these disasters are monitoring and prevention.
Natural disasters usually cause great material and economic losses, and often also cost many people their lives. The governments of countries that are usually affected by this type of extreme natural events usually take measures to mitigate damage and anticipate the occurrence of these phenomena as much as possible.
Natural disasters are caused by the emergence of an extreme natural phenomenon that negatively affects the population of a certain place. Earthquakes, for example, are caused by a sudden movement of the Earth’s crust and are usually very difficult to anticipate and predict. For this reason, they usually surprise the population who, sometimes, does not have time to take the necessary precautionary measures to stay safe.
Other phenomena such as hurricanes or volcanic eruptions usually give more time in advance, and with correct monitoring of their evolution they can be predicted several days in advance.
Natural disasters or environmental problems? Natural disasters are often confused with environmental problems. Natural disasters are events produced by nature without human intervention and that seriously affect people. Environmental problems also have negative effects on society, but they are produced by human activities. The eruption of a volcano or an earthquake are natural disasters, while deforestation or soil contamination are environmental problems.
Geological natural disasters
Geological natural disasters are:
- Earthquakes. They are strong vibrations of the Earth’s crust produced by a release of energy inside the planet. They are generated by the movement of the tectonic plates that make up the Earth’s surface. When they are of great magnitude, they usually cause significant damage to the structures that are on the surface. To measure the damage they cause, the Mercalli scale is used, which establishes values from 0 to 12 depending on the destruction caused.
- Volcanic eruptions. They occur when the magma accumulated inside a volcano comes to the surface in the form of an eruption. Explosive volcanic eruptions are the ones that produce the greatest number of natural disasters. The geological monitoring centers of countries that have active volcanoes measure the temperature inside the volcanoes. The significant increase in the internal temperature of the volcano may lead to its eruption, which makes it possible to anticipate prevention and mitigation measures.
- Tsunamis. They are caused by earthquakes that occur on the seabed. These earthquakes produce a sudden movement of the ocean plates, which generates a large release of energy that is transferred to the water through waves and can cause the formation of a tsunami. When these seismic waves reach the coast, large waves are formed that can cause significant damage to structures and people near the beaches.
Natural meteorological disasters
Natural meteorological disasters are:
- Hurricanes. They are tropical storms that form in the sea and usually cause winds with speeds greater than 100 kilometers per hour. These winds rotate around a central axis as the hurricane moves across the ocean. The diameter of this spiral of winds can reach 1,500 kilometers. Upon reaching the continent, these large storms cause severe damage to structures and can cause the death of people. With correct satellite monitoring, their paths can be anticipated and prevention and evacuation measures taken before the storms reach the continent.
- Tornadoes. They are winds that rotate in a funnel shape from the base of a storm cloud towards the surface. They are commonly accompanied by rain and hail. They can reach 500 kilometers per hour. It is a meteorological phenomenon that can be predicted with very little advance notice, and although they are usually short-lived, they can cause great damage to the Earth’s surface.
- Forest fires. They occur when, due to the effect of heat and lack of rain, a fire is generated inside a forest or grassland, and the fire spreads to inhabited places. Fires caused intentionally or accidentally by humans are not considered natural disasters. Only fires that occur naturally and negatively affect societies are considered natural disasters. They are much more frequent in the hot months, and are impossible to anticipate. When the fire is detected, the authorities usually deploy fire control operations with firefighters and hydrant planes to try to control the flames and put it out in the shortest time possible.
Floods and droughts They are often considered natural disasters. However, these extreme events have social causes in addition to natural ones. Floods and droughts tend to occur much more due to incorrect urban planning, irregular occupation of flood-prone areas, overexploitation of resources or deforestation than due to excess or lack of rain. For this reason it is not correct to consider them natural disasters but rather it is more appropriate to classify them as environmental problems.
Can natural disasters be foreseen and prevented?
Most natural disasters They are unpredictable because they do not have a specific frequency. This is the case of earthquakes, tsunamis, tornadoes or volcanic eruptions, which can happen at any time of the year.
However, sometimes they present patterns that allow their occurrence to be predicted with some advance notice. Hurricanes, for example, always happen between the months of June and November. Fires, for their part, tend to be much more frequent in the summer months, and it is very rare for them to occur in the coldest months of the year.
As it is not possible to avoid the occurrence of natural disasters, societies develop prevention strategies to mitigate the damage they can cause.
Places located in areas where these types of events usually occur have alarm and early detection systems that allow anticipating the occurrence of the disaster. In addition, people are usually trained to know how to act when a disaster occurs and where and how to evacuate if necessary.
In areas that are seismically active and earthquakes occur with some frequency, The buildings are made with anti-seismic technology which allows them to better resist ground vibrations. In tornado and hurricane zones, houses have shelters so that people can take shelter while the event happens and stay safe.
Global monitoring bodies for natural disasters
Some of the most important organizations and monitoring of natural disasters in the world are:
- The Pacific Tsunami Warning Center. It is one of the most important tsunami warning systems in the world and covers most of the Pacific Ocean.
- The National Hurricane Center. It is responsible for monitoring and predicting the occurrence of hurricanes in the Atlantic Ocean.
- The Smithsonian Volcano Research Institute. It has been responsible for monitoring volcanic activity worldwide since 1968.
- The Global Forest Fire Information System. It uses satellite images to monitor the occurrence of fires in real time. It was developed by NASA in the United States.
Major natural disasters in history
Some of the most important natural disasters in history were:
- In the year 79 AD. C. the eruption of Mount Vesuvius, which buried the Roman city of Pompeii under ashes.
- The Indian Ocean tsunami in 2004, which killed more than 230,000 people.
- The Haiti earthquake in 2010, which caused the death of more than 300,000 people.
- Hurricane Katrina in 2005 in the United States is considered the most devastating in history. It caused material damage of approximately 250,000 million dollars.
References
- National Hurricane Center. NHC
- Smithsonian Volcano Research Institute. Volcano
- United Nations Organization (2021). Climate-related natural disasters have increased five-fold in 50 years, but improved warning systems save more lives. A
- Sánchez, J. (2022). Types of natural disasters that exist. EcologyGreen
- Tarbuck, E., & Lutgens, F (1999). Earth Sciences. An introduction to physical geology. Prentice Hall.
