Natural Disasters

Natural disasters are naturally occurring events that directly or indirectly lead to the destruction or loss of life, property, or the environment. Natural disasters often leave thousands homeless and at risk of exposure, disease, and starvation. Examples include weather phenomena, such as tornadoes, hurricanes, or drought, and geological events, such as earthquakes and volcanoes. Flooding, landslides, and wildfires can also occur naturally and have devastating effects in populated area of the globe.

The destructive force of severe storms, such as tornadoes and tropical storms (hurricanes, cyclones, and typhoons), often results in the loss of both life and property. Tornadoes produce the most intense and high winds and are among the strongest ever recorded. They can level entire neighborhoods, uproot trees, and hurl people and animals through the air. High wind also creates hazards from flying and falling debris. Tornado “outbreaks” are common and can travel for miles before subsiding. Before the advent of Doppler radar, there was little or no warning, and the death toll for many storms reached into the hundreds.

Hurricanes also generate strong winds that can destroy property and cause flying debris. As a hurricane approaches land, it also generates its most destructive force: storm surge, which can inundate coastal areas, cause wide ranging floods, and sweep away entire communities. Since hurricanes form far out at sea and can be tracked by air and satellite, most communities know well in advance if a hurricane is headed their way. However, this was not the case with Hurricane Ian, which made landfall in Florida on September 28, 2022. The storm was initially projected to strike Tampa Bay but changed course and struck Fort Myers and surrounding areas. The storm decimated Fort Myers Island as well as Sanibel and Pine Islands. More than one hundred people died, mostly from drowning. Some did not have time to evacuate.

Flooding is often caused by seasonal conditions, such as rain and snow. In the geographic interior, flooding occurs when a river or lake overflows its banks, often the result of too much rain or snowmelt. In coastal areas, storm surge and tsunamis can cause flooding as far as 10 miles inland. River valleys and canyons can become inundated by heavy rains. Land that is underwater becomes uninhabitable; in populated and industrialized areas, people may be exposed to the threat of pollution and water-borne diseases. Water, sewage, and electrical grids may no longer function. It can take days or weeks for floodwaters to recede and months or even years after that before the communities affected become habitable and life returns to normal. Flooding can sometimes happen too quickly for people to escape, and the resulting loss in life can reach into the hundreds or thousands.

Tsunamis are most often the result of underwater earthquakes. The sudden movement of an underwater land mass, such as an earthquake, landslide, volcanic eruption, or other explosion, displaces the water above it to form a wave train. The initial height, or amplitude, of a tsunami wave may reach just a few inches above mean sea level, but as it approached the shore, the wave is compressed and, by an effect known as shoaling, can grow to several feet and inundate coastal areas for miles inland. The 2004 Indian Ocean tsunami devastated coastal areas throughout Indonesia, Sri Lanka, and India, and it was observed as far west as Madagascar and the east African coast. Whole islands and coastal communities were completely wiped out. Of the hundreds of thousands lost or killed, many are thought to have washed out to sea as the tidal waves receded back into the ocean.

Drought is a condition where, over an extended period of time, there is less rainfall than normally expected for a given region. Droughts are generally seasonal but vary widely in their severity and predictability. In areas where humans are utterly dependent on agriculture and livestock for survival, the effects of drought can be devastating. In the early part of the twentieth century, droughts in rural India, Russia, and China led to widespread famine and claimed millions of lives.

In 2019 and 2020, drought and higher-than-normal temperatures caused out-of-control wildfires in parts of Australia, destroying more than 44 million acres of land and causing about one-hundred-billion dollars in damage. At least 455 people died.

Earthquakes are waves of seismic energy (vibrations) that travel through the earth’s crust. At the surface, earthquakes are felt as a shaking or sudden shift in the ground. They are most often caused by shifts along various ruptures, or faults in the earth’s crust. The vast majority of such events go unnoticed, owing to their small magnitude or remote location. In certain parts of the world, however, earthquakes are a major destructive force, causing mudslides and tsunamis, bringing down homes, schools, and other buildings. The majority of deaths associated with earthquakes occur when people are trapped or crushed in collapsed buildings or struck by falling debris. Earthquakes can be particularly devastating when they strike in or near heavily populated areas or in poorer regions where buildings and other structures are not built to withstand the powerful forces an earthquake can generate. In certain areas, earthquakes can also cause landslides, avalanches, and floods. In urban areas, fires caused by ruptured gas or electrical lines can lead to yet more property damage and, as in the case of the 1906 San Francisco earthquake, more deaths than those caused by the earthquake itself.

Volcanoes are relatively rare, as natural disasters go. While volcanoes occur throughout the world, many are under water or in regions too remote to have a significant human impact. Further, most volcanic eruptions are not the cataclysmic events so often depicted in Hollywood movies; according to the US Geological Survey, of the ten deadliest volcanic eruptions since 1500 CE, only two occurred in the twentieth century, in 1905 and 1985. In addition to being caught in lava (pyroclastic) flows or asphyxiated by falling ash, many casualties stem from secondary causes, such as mudslides, tsunamis, and starvation. Areas surrounding an erupting volcano may become uninhabitable, often for years after the eruptions have stopped.

Landslides occur when soil, loosened by rain, erosion, or seismic activity, breaks loose from the side of a hill or mountain and slides to the bottom. Minor landslides are a fairly common event following heavy rains in mountainous or hilly terrain. However, major landslides can erupt unexpectedly and pose a serious threat to anyone living or working below. Slides can also block rivers and roads, destroy trees, bridges, houses, and other structures, and bury anything in their paths. In the worst cases, large, catastrophic mudslides can bury entire villages or towns beneath several feet of mud and debris, killing tens of thousands at a time.

Wildfires are uncontrolled fires that burn through wilderness areas such as forests, grasslands, and other areas with sufficient vegetation to fuel the fire. Wildfires occur naturally in almost every part of the world; certain plant species depend on them for survival, and most other plant and animal species have adapted defense strategies to mitigate the harmful effects. However, in many areas, wildfires have been suppressed over time, adding to the available fuel stored in the vegetation. It is often in these same areas that human habitation has spread, so that when fires do erupt, they burn hotter and more violently, spread more quickly, and destroy homes and other property in the way.

It is virtually impossible to control when and where events such as these might occur. The best one can hope for is to minimize the impact these events have on human life, property, and habitation. For example, early warning systems for tornadoes have substantially reduced the number of fatalities each year, as residents can seek shelter from these violent storms before they strike. A similar early warning system for tsunamis might also reduce the number of casualties. High-rise buildings, bridges, and other structures can be reinforced to withstand the forces of an earthquake or the high winds brought by tropical storms. Better irrigation and flood control can mitigate the effects of seasonal flood and drought conditions. Those practicing modern forest management have begun to experiment with the use of controlled burns in wilderness areas, thus avoiding the catastrophic effects of natural wildfires.

Those who survive the initial impact of natural disasters are still at risk for disease, starvation, and injury. In many countries, both government and nongovernment agencies have been established to respond by providing aid and relief to those affected. These services normally include medical and other first-aid treatment, provisioning of food and clean water, environmental damage assessment and cleanup, and helping with the financial and economic recovery of disaster victims and their communities.