Natural disasters are no fun to experience. They are horrible, overwhelming, intense, and frightening. But the world we love would not exist without the countless disasters that created our home planet. Can you imagine a world without mountains and valleys? Without mountains, there would be no rivers. The world would be vast oceans, with land washed away by the force of ocean waves. Without earthquakes, the world would be watery. The land landscapes we love would not exist because of the formation of mountains, which are uplifted by earthquakes and created by volcanoes. Coasts exist because the land rose above the sea. And it is because the land rose above the sea that earthquakes made it possible for life as we know it to exist. Disasters are disastrous for us, but they are also beneficial to the ecosystems of which we are a part and on which we depend. The world we love would not exist without the disasters that built it.
Our world is full of natural hazards, or natural processes, that pose a potential threat to human life and property. Without human life and property, any event on Earth that causes sudden change is not technically a disaster. Disasters are purely human experiences, but we recognize that plants and animals are often adversely affected as well. But those plants and animals would not exist without the events that created the landscapes to which ecosystems have adapted. Earthquakes create mountains, floods replenish groundwater, hurricanes recycle nutrients, wildfires remove excess undergrowth and allow some seeds to germinate, volcanoes create rocks that become new landscapes, landslides expose rocks that decompose into fertile soil. The world we love is created by events that cause change, but it is events that become disasters. An event that occurs within a specific geographic area and over a limited period of time, results in 10 or more deaths, affects at least 100 people, and leads to the declaration of a state of emergency and a request for international assistanceIn the worst case scenario, a disaster can escalate into a catastrophe, requiring significant costs and long recovery times. Catastrophes only occur if the event is widespread or occurs in a densely populated area and affects many people. Disasters and catastrophes only occur when humans are adversely affected by rapid natural events, and greater population density increases the likelihood of disasters and catastrophes.
In 79 AD, Mount Vesuvius erupted in Italy. The cities of Pompeii and Herculaneum were buried under hot volcanic rocks. The same volcanic rocks that made up the volcano before this eruption created the soil, making the valleys at the foot of the volcano fertile and supporting a civilization that enjoyed grain, wine, olives, and honey. The volcanic disaster that occurred over a few days may have buried the cities, but it also preserved them, allowing modern archaeologists to investigate how people in the area lived almost 2000 years ago. Italians built on the buried remains of these Roman cities, and today the city of Naples and surrounding towns are spread out on the slopes of the still-active volcano. Mount Vesuvius will cause another natural disaster, but due to the very dense population and limited evacuation routes, it is very unlikely that everyone will be able to escape the devastation. Meanwhile, thanks to the rocks produced by past eruptions, the current agricultural wealth can support the cities at the foot of the volcano.
In 1989, the Loma Prieta earthquake struck the San Francisco Bay Area, California, causing devastation near and far from the epicenter of Mt. Loma Prieta. Mt. Loma Prieta would not have been a peak if thousands of earthquakes had not occurred over millions of years, slowly raising the rocks into a mountain. It is a peak because it is a fault within the San Andreas Fault System, a crustal boundary that runs along the California coast. The presence of faults means that natural disasters are always looming. The beloved mountains, valleys, vineyards and sequoias of the San Francisco Bay Area, California, would not exist without the faults that underlie the region. A network of hundreds of faults created this landscape, and faults formed millions of years ago caused volcanoes to erupt. Volcanic rocks eroded, forming the rich soil that supports California’s wine region, in the middle of a seismic region. From devastation comes beauty.
In 2017CE, Hurricane Irma struck the Florida coast, damaging 40% of the region’s coastal mangrove forests. A nearly 9-foot storm surge flooded the area, and strong winds tore mangroves from the soil in the marshes of Everglades National Park. The rotting remains of the mangroves still affect the local ecosystem, contributing to algae blooms that destroy sensitive aquatic habitats. The area has weathered many storms, but would not exist without the continued flooding that forms the marshes and the nutrients that are exposed when storms churn up the water and mud. Everglades plants photosynthesize and capture carbon, burying it in the marsh soil, which eventually becomes deep enough to be compressed into coal over millions of years. The Everglades could not exist without its vast amounts of water. The role of aquatic ecosystems in removing carbon dioxide from the atmosphere and trapping it in the soil influences global temperature change, similar to the role played by the Amazon rainforest on a larger scale. All wetland forests protect shorelines from erosion, sequester carbon, replenish groundwater, and provide habitat for plants and animals that cannot live anywhere else.
As you appreciate the world around you, think about the role disasters played in its formation. Every time you see a mountain, remember that it was created by earthquakes and volcanic eruptions. When you see a river, remember that without the earthquakes that uplifted the mountains, the valley would not have had the slope for the water to flow down. When you see a fertile field, remember that its soil was formed by the collapse of rocks from volcanoes, glaciers, wind, and rivers, and the remains of plants and animals from past generations. When you see a marsh, know that flooding allows it to exist. Natural disasters are painful to experience, but the world we love would not exist without the disasters that the ancestors of every species on Earth survived. Every life form on Earth has a legacy to survive, and humans are uniquely positioned to either support the survival of the entire ecosystem of Earth or feel victimized by events that have been happening for millions of years. We can cause further disasters by our misuse of energy and resources, but we can also prevent them by our management of the landscape, air, water, and ecosystems. Natural disasters are creative and destructive Earth processes, and as Earthlings, humans and our civilization are affected by Earth processes that created and continue to shape the Earth.
