Ch 1 Intro to Natural Disasters (2023)

Chapter 1: Introduction to Natural Disasters

The goals and objectives of this chapter are to:

  • Describe how scientists use scientific and geographic literacy, inquiry, and methodology to understand the earth.
  • Explain the science and interconnectedness natural processes
  • Determine how natural hazards become disasters and catastrophes.
  • Determine how humans are making natural processes magnified on society.

Scientific and Geographic Inquiry

A volcanologist sampling lava using a rock hammer and a bucket of water.

Science is a path to gaining knowledge about the natural world. The study of science also includes the body of knowledge that has been collected through scientific inquiry. To conduct a scientific investigation, scientists ask testable questions that can be systematically observed and careful evidenced collected. Then they use logical reasoning and some imagination to develop a testable idea or claim, called ahypotheses, along with explanations to explain the idea. Finally, scientists design and conduct experiments based on their hypotheses.

Scientists seek to understand the natural world by asking questions and then trying to answer the questions with evidence and logic. A scientific question must be testable and supported by empirical data; it does not rely on faith or opinion. Our understanding of natural Earth processes help us to understand why earthquakes occur where they do and how to understand the consequences of adding excess greenhouse gases into the atmosphere.

Scientific research may be done to build knowledge or to solve problems and lead to scientific discoveriesand technological advances. Pure research often aids in the development of applied research. Sometimes the results of pure research may be applied long after the pure research was completed. Other times something unexpected is discovered while scientists are conducting their research. Some ideas are not testable. For example, supernatural phenomena, such as stories of ghosts, werewolves, or vampires, cannot be tested.Scientists describe what they see, whether in nature or in a laboratory.

Science lies in the realm of facts, observations, and empirical evidence, not in the realm of moraljudgments. Scientists might enjoy studying tornadoes, but their opinion that tornadoes are exciting is not important to learning about them. Science has helped society increase our knowledge and understanding of the physical and cultural world we live in, but it does not determine how we should use that knowledge to advance humanity. Scientists learned to build an atomic bomb, but scientists didn’t decide whether or when to use it. Scientists have accumulated data on warming temperatures; heir models haveshown the likely causes of this warming. But although scientists are largely in agreement on the causes of global warming, they can’t force politicians or individuals to pass laws or change behaviors.

For science to work, scientists must make some assumptions. The rules of nature, whether simple or complex, are the same everywhere in the universe. Natural events, structures, and landforms have natural causes and evidence from the natural world can be used to learn about those causes. The objects and events in nature can be understood through careful, systematic study. Scientific ideas can change if we gather new data or learn more. An idea, even one that isaccepted today, may need to be changed slightly or be entirely replaced if new evidence is found that contradicts it. Scientific knowledge can withstand the test of time because accepted ideas in science become more reliable as they survive more tests.

Geography is the study of the physical and cultural environments of the earth. What makes geography different from other disciplines is it's focus on spatial inquiry and analysis and how they change over time. Geographers also try to look for spatial and historical connections between things such as patterns, distribution, movement and migration, flow, trends and more. This process is calledgeographicorspatial inquiry.

In order to to this, geographers go through a geographic methodology that is quite similar to the scientific method, but again with a geographic or spatial emphasis. This method can be simplified in a six step

geographic inquiry process.

  1. Ask a geographic question.This means to ask questions about spatial relationships in the world around you.
  2. Acquire geographic resources.Identify data and information that you need t answer your question.
  3. Explore geographic data.Turn the data into maps, tables, and graphs, and look for patterns and relationships.
  4. Analyze geographic information.Determine what the patterns and relationships mean with respect to your question.

"Knowing where somethingis, how its location influences its characteristics, and how its location influencesrelationships with other phenomena are the foundation of geographic thinking. This modeof investigation asks you to see the world and all that is in it in spatial terms. Like otherresearch methods, it also asks you to explore, analyze, and act upon the things you find. Italso is important to recognize that this is the same method used by professionals aroundthe world working to address social, economic, political, environmental, and a range ofscientific issues." (ESRI)

You have probably learned that thescientific methodis a series of steps that help to investigate To answer those questions, scientists use data and evidence gathered from observations, experience, or experiments to answer their questions.

But scientific inquiry rarely proceeds in the same sequence of steps outlined by the scientific method. For example, the order of the steps might change because more questions arise from the data that is collected. Still, to come to verifiable conclusions, logical, repeatable steps of the scientific method must be followed.A flow chart of how science works that is much more accurate than the simple chart above is found here:. This video of The Scientific Method Made Easy explains scientific method succinctly and well.

The most important thing a scientist can do is to ask questions.

  • What makes Mount St. Helens more explosive and dangerous than the volcano on Mauna Loa, Hawaii?
  • What makes the San Andreas fault different than the Wasatch Fault?
  • Why does Earth have so many varied life forms but other planets in the solar system do not?
  • What impacts could a warmer planet have on weather and climate systems?

Earth science can answer testable questions about the natural world. What makes a question impossible to test? Some un-testable questions are whether ghosts exist or whether there is life after death. A testable question might be about how to reduce soil erosion on a farm. A farmer has heard of a planting method called “no-till farming.” Using this process eliminates the need for plowing the land. The farmer’s question is: Will no-till farming reduce the erosion of the farmland?

To answer a question, a scientist first finds out what is already known about the topic by reading books andmagazines, searching the Internet, and talking to experts. This information will allow the scientist to create a good experimental design. If this question has already been answered, the research may be enough or it may lead to new questions. Example: The farmer researches no-till farming on the Internet, at the library, at the local farming supply store, and elsewhere. He learns about various farming methods, as illustrated in the Figure 1.3. He learns what type of fertilizer is best to use and what the best crop spacing would be. From his research he learns that no-till farming can be a way to reduce carbon dioxide emissions into the atmosphere, which helps in the fight against global warming.

With the information collected from background research, the scientist creates a plausible explanation for the question. This is ahypothesis. The hypothesis must directly relate to the question and must be testable using empirical evidence. Having a hypothesis guides a scientist in designing experiment, collecting data, and analyzing and interpreting the results. The hypothesis is always stated as an explanation and not a question. Example: The farmer’s hypothesis is this: No-till farming will decrease soil erosion on hills of similar steepness as compared to the traditional farming technique because there will be fewer disturbances to the soil.

To support or refute a hypothesis, the scientist must collect data. A great deal of logic and effort goes into designing tests to collect data so the data can answer scientific questions. Data is usually collected by experiment or observation. Sometimes improvements in technology will allow new tests to better address a hypothesis.

Observation is used to collect data when it is not possible for practical or ethical reasons to perform experiments. Written descriptions are qualitative data based on observations. This data may also be used to answer questions. Scientists use many different types of instruments to make quantitative measurements. Electron microscopes can be used to explore tiny objects or telescopes to learn about the universe. Probes make observations where it is too dangerous or too impractical for scientists to go. Data from the probes travels through cables or through space to a computer where it is manipulated by scientists.

Experiments may involve chemicals and test tubes, or they may require advanced technologies like a high-powered electron microscope or radio telescope. Atmospheric scientists may collect data by analyzing the gases present in gas samples, and geochemists may perform chemical analyses on rock samples.

A good experiment must have one factor that can be manipulated or changed. This is the independent variable. The rest of the factors must remain the same. They are the experimental controls. The outcome of the experiment, or what changes as a result of the experiment, is the dependent variable. The dependent variable “depends” on the independent variable.

Example: The farmer conducts an experiment on two separate hills. The hills have similar steepness and receive similar amounts of sunshine. On one, the farmer uses a traditional farming technique that includes plowing. On the other, he uses a no-till technique, spacing plants farther apart and using specialized equipment for planting. The plants on both hillsides receive identical amounts of water and fertilizer. The farmer measures plant growth on both hillsides.In this experiment:

  • What is the independent variable?
  • What are the experimental controls?
  • What is the dependent variable?

The independent variable is the farming technique—either traditional or no-till—because that is what is being manipulated. For a fair comparison of the two farming techniques, the two hills must have the same slope and the same amount of fertilizer and water. These are the experimental controls. The amount of erosion is the dependent variable. It is what the farmer is measuring. During an experiment, scientists make many measurements. Data in the form of numbers is quantitative.

Data gathered from advanced equipment usually goes directly into a computer, or the scientist may put the data into a spreadsheet. The data then can be manipulated. Charts and tables display data and should be clearly labeled. Statistical analysis makes more effective use of data by allowing scientists to show relationships between different categories of data. Statistics can make sense of the variability in a data set. Graphs help scientists to visually understand the relationships between data. Pictures are created so that other people who are interested can see the relationships easily.

In just about every human endeavor, errors are unavoidable. In a scientific experiment, this is called experimental error. What are the sources of experimental errors? Systematic errors may be inherent in the experimental setup so that the numbers are always skewed in one direction. For example, a scale may always measure one-half ounce high. The error will disappear if the scale is re-calibrated. Random errors occur because a measurement is not made precisely. For example, a stopwatch may be stopped too soon or too late. To correct for this type of error, many measurements are taken and then averaged. If a result is inconsistent with the results from other samples and many tests have been done, it is likely that a mistake was made in that experiment and the inconsistent data point can be thrown out.

Scientists study graphs, tables, diagrams, images, descriptions, and all other available data to draw a conclusion from their experiments. Is there an answer to the question based on the results of the experiments? Was the hypothesis supported? Some experiments completely support a hypothesis and some do not. If a hypothesis is shown to be wrong, the experiment was not a failure because all experimental results contribute to knowledge. Experiments that do or do notsupport a hypothesis may lead to even more questions, more experiments and more answers.

​As scientists conduct experiments and make observations to test a hypothesis, over time they collect a lot of data. If a hypothesis explains all the data and none of the data contradicts the hypothesis, the hypothesis becomes a theory. A scientific theory is supported by many observations and has no major inconsistencies. A theory must be constantly tested and revised. Once a theory has been developed, it can be used to predict behavior. A theory provides a model of reality that is simpler than the phenomenon itself. Even a theory can be overthrown if conflicting data is discovered. However, a longstanding theory that has lots of evidence to back it up is less likely to be overthrown than a newer theory.

Science does not prove anything beyond a shadow of a doubt; scientists seek evidence that supports or refutes an idea. If there is no significant evidence to refute an idea and a lot of evidence to support it, the idea is accepted. The more lines of evidence that support an idea, the more likely it will stand the test of time. The value of a theory is when scientists can use it to offer reliable explanations and make accurate predictions.

Understanding Natural Hazards

Because of the scientific method, we now understand where and why most natural disasters occur. For example, because of the theory of plate tectonics, we understand why nearly 90 percent of all earthquakes and volcanoes occur along the outer edges of the Pacific Ocean, called the Ring of Fire. The theory of plate tectonics has also helped to explain why some volcanoes are more explosive and active than others. We also understand that different tectonic plate boundaries produce different fault lines and thus different types of earthquakes.

Many natural hazards have seasons, especially those controlled by external forces. The United States has more tornadoes than the rest of the world combined and yet most only occur in the spring and early fall. Landslides are more prone in the spring when snow begins to melt and the saturated ground causes unstable slopes to slide. Wildfires are common in the middle of the summer and early fall when the land is dry and afternoon thunderstorms in arid climates produce lightning without any precipitation. And hurricane season in the Northern Hemisphere peaks between August and September when the Atlantic Ocean is warmest.

Since hazards are statistically predictable in some manner, it becomes important to develop some kind of warning system. Predictions, such as weather predictions, state that it will occur at a specified time, date, and intensity. It is like saying, "a major snowstorm will reach Salt Lake City at 4:30 PM for the commute home." A forecast states a probability of something occurring; such as "a 40 percent of showers today." Forecasts are much more broad than predictions.

When a natural disaster event is about to happen or has occurred, a system has been set up to alert the general public. A watch is issued when the conditions for a particular event are right. So if a severe thunderstorm is strong enough and rotating, it is possible that a tornado may form. Or if an earthquake with a magnitude of 7.5 strikes somewhere in the ocean, a tsunami watch may be issued because the earthquake was strong enough to generate one. But a watch does not necessarily mean that it will occur. But if a tornado is spotted on the ground or a ocean sensor records an approaching tsunami, then a warning is sent out to the areas that could be impacted.

In order to understand how to prepare for a natural hazard, a risk assessment must be conducted for a specific geographic area. The risk of a potential hazard is defined as probability of a disaster times the consequence to the human environment.

  • Risk = Probability of Disaster x Consequence of Disaster

It is important to determine the potential risk a location has for any particular disaster in order to know how to prepare for one. Referring back to Salt Lake City again, the probability of an earthquake occurring anytime soon is small, but the consequences to human lives and destruction are very high. Thus there is a moderately high risk of an earthquake striking Salt Lake City. One of the limiting factors of risk is knowing the probability of a disaster. Too often scientific data is lacking enough information to determine how often a disaster occurs for a particular location. This is particularly true with geologic hazards, where geologic time is vastly larger than the age of scientific reasoning.

What is the difference between a natural hazard, a disaster, or a catastrophe?Ahazardis any natural process or even that poses a direct threat to the human environment. The event itself is not a hazard; rather, a process or event becomes a hazard when it threatens human interests.Adisasteris the effect of a hazard on society, usually as an event that occurs over a limited time in a defined geographic area. The term disaster is used when the interaction between humans and a natural process results in significant property damage, injuries, or loss of life.Finally, acatastropheis a massive disaster that greatly impacted the human environment and requiring significant expenditure of time, money, and resources for response and recovery.

Currently the earthquake that is expected to strike Salt Lake City is just a hazard, a natural process that poses a potential treat the human environment, because it hasn't occurred yet. If that earthquake turns out to be a moderate 5.0 magnitude earthquake than it will likely be considered a disaster. But if the expected 7.0 to 7.5 magnitude earthquake were to occur, it would be considered a catastrophe because thousands of people will likely perish, tens of thousands will be injured, and the economic cost will be in the billions of dollars. An article by NASA titledThe Rising Costs of Natural Hazardstalks about how the financial and human cost of natural disasters is rising. To help prepare for these disasters, bettermitigationefforts will be required such as proper building and zoning codes, first responder preparedness, and public education.

Natural hazards tend to produce more natural hazards. A major landslide may destabilize a slope and cause more landslides to occur. An earthquake in Salt Lake City is likely to also cause landslides, fires, and the ground to liquefy (liquefaction). Hurricanes tend to produce damaging winds, tornadoes, and flooding. Thus it is important to know which disasters are likely to occur in any particular area and what their effects might be.

In the summer of 2008, China was rocked by a magnitude 8.0 earthquake that killed over 80,000 people. A week earlier a cyclone struck Burma killing 130,000. On January 12, 2010 a magnitude 7.0 earthquake killed nearly 300,000 people and leveled the capital city of Port-a-Prince in Haiti. On March 11, 2011 a magnitude 9.0 earthquake generated a tsunami off the coast of eastern Japan, killing 30,000 people. Are natural disasters getting worse? Not really. Humans are over-populating the earth and living in more hazard-prone areas. Over the last 70 years, the world's population has tripled to 6.7 billion. World population projections suggest that the human population will reach 9 billion by 2050. by exponentially grow and by 2050 the world's population will reach 9 billion.Exponential growthmeans the world's population will not grow linearly (in a straight line), but rather as a percent. Our increased population size has caused air quality to suffer, reduced the availability of clean drinking water, increased the world's extreme poverty rate, and has made us more prone to natural hazards.

There is also a relationship between themagnitudeof an event (energy released) and itsfrequency(intervals between episodes). The more earthquakes that occur for a particular location, the weaker they tend to be. That is because built-up energy is slowly being released at a fairly constant rate. But if their are long intervals between one earthquake and the next, the energy can build and can ultimately produce a stronger earthquake. That is the problem with earthquakes along the Wasatch Front of Utah. The interval or frequency between earthquakes tends to be 1,500 years, so the magnitude tends to be high because of the built-up energy. At some point we are going to want to get this earthquake over with because the longer it waits the worse it will be.

Too often we react to natural disasters rather than prepare or mitigate for them. Look at New Orleans with Hurricane Katrina. The scientists and engineers had said for years that the levees would not withstand a strong hurricane, but it would cost over $6 billion to upgrade them. Not that the has disaster occurred, we are now rebuilding the levees (most have found the money) at the expense of 1,500 lives and nearly $200 billion in damages. He need to change this mentality. Too often we say the government does not have the right to tell me where I can or can not live, but when the disaster strikes we expect the government to bail up out. Sounds a little like the financial crisis.

Lava on Mauna Loa, Hawaii

Hurricanes in the Atlantic Ocean

There are two types of effects caused by natural disasters: direct and indirect.Directeffects, also calledprimary effects, include destroyed infrastructure and buildings, injuries, separated families, and even death.Indirect, sometimes calledsecondary effects, are things like contaminated water, disease, and financial loses. In other words, indirect effects are things that happenafterthe disaster has occurred.

How we chose to build our cities will greatly determine how many lives are saved in a disaster. For example, we should not be building homes in areas that are prone to landslides, liquefaction, or flash floods. Rather these places should be left as open-space such as parks, golf courses, or nature preserves. This this is a matter of proper zoning laws which is controlled by local government. Other ways we can reduce the impact of natural disasters is by having evacuation routes, disaster preparedness and education, and building codes so that our building do not collapse on people.

There are two forces that generate natural hazards. The first are internal forces, generated by the internal heat of the earth and creates geologic hazards like earthquakes, volcanoes, and tsunamis. In Chapter 2, you will learn about this process calledplate tectonics. This theory proposes that internal heating from the earth's core causes large tectonic plates, that make up the planet's continents and oceans, to move around like bumper cars, where they either slam into each other or pull apart.

External forces influence weather, climate, and landslides. Heating from the Sun causes differential heating on the surface that ultimately create our weather and all the hazards associated with it. It is these external forces that create flash floods, tornadoes, hurricanes, supercells, and climatic disasters such as droughts and famines.

Unnatural Disasters

Former UN Security General Kofi Annan has said, “The term natural disaster has become increasingly a misnomer. In reality, human behavior transforms natural hazards into unnatural disasters.”The vast majority of deaths from natural disasters occurs in less developed countries. According to the United Nations, a less developed country (LDC) is a country that exhibits the lowest indicators of socioeconomic development and ranked among the lowest on the Human Development Index. Those who live in low income environments tend to have the following characteristics:

  • live in areas that are at a higher risk to geologic, weather, and climate-relateddisasters
  • live in areas that lack the economics and resources to provide a safe living infrastructure for its people
  • tend to have few social and economic assets and a weak social safety net
  • lack the technological infrastructure to provide early warning systems

As human populations have grown and expanded, and technology has allowed for us to manipulate the environment, natural disasters have become more complex and arguable more "unnatural." There are a variety of ways how humans have not only influenced, but magnified the impacts of disasters on society. For purposes of simplification, this book is going to narrow it down to four: human population growth, poverty and inequality, environmental degradation, and climate change.

In 1798, Thomas Malthus published a short but revolutionary work called“An Essay on the Principle of Population.” Malthus states that future population growth would be determined by two facts and one opinion. The facts were that food is necessary for survival and that men and women would continue to have sex, thus producing offspring. His opinion is that if population is not restrained by war, famine, and/or disease, population growth would occur exponentially. An example of exponential growth is 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 and so on. He also argues that agricultural production of food could only grow arithmetically. An example of arithmetic growth is 1, 2, 3, 4, 5, 6, 7 and so on. The overall assumption is that population growth will quickly grow beyond food production leading to food shortages and famines.

Malthus' theory has not come to fruition, yet, due to technological advances in agriculture (fertilizers, insect and droughtresistance and better farming techniques). Some discredit Malthus because his hypothesis is based on a world supply of resources being fixed rather than expanding. Humans have the ability to expand the supply of food and other resources by using new technologies to offset scarcity of minerals and arable land. Thus, we can use resources more efficiently and substitute new resources with scarce ones. Even with a global human population of 7 billion, food production has grown faster than the global rate of increase (NIR). Better growing techniques, higher-yielding and genetically modified seeds, as well as cultivation of more land have helped expand food supplies.

While new technologies have helped to increase food production, there are not enough emerging technologies to handle supply and demand. Adding to the problem is the fact that many insects have developed a resistance to pesticides. These problems have cause a slow down and leveling off of food production in many regions of the world. Without breakthroughs in safe and sustainable food production, food supply will not keep up with population growth.

Others believe that population growth isn't a bad thing. A large population could stimulate economic growth, and therefore, production of food. Population growth could generate more customers and more ideas for improving technology. Additionally, some maintain that no cause-and-effect relationship exists between population growth and economic development. They argue that poverty, hunger, and other social welfare problems associated with lack of economic development, famines, and war are a result of unjust social and economic institutions, not population growth.

Lately, there has been a rise in neo-Malthusians. One notable figure is Paul Ehrlich. In his very popular book, The Population Bomb, Ehrlich argues that population growth cannot continue without controls because the planet will reach the carrying capacity of our species. In short, we must consider environmental factors as we discuss overpopulation concerns. For example, even though humans produce four times the amount of food that we consume, we produce our food at the price of the environment. The rapid population growth of the world has caused massive deforestation in the Boreal Forests and rainforests, increasing desertification that encroaches into arable land, over-fishing of the oceans, mass extinction of species, air and water pollution, and anthropogenic (human-induced) climate change. All of these things have economic and environmental costs that we must consider.

Governments and other entities have the ability to dramatically influence population change as a way to increase or decrease population growth in a particular country. For example, some countries take dramatic steps to reduce their population. China's One-Child Policydictated that each family (husband and wife) could legally have only one child. Families that followed this policy were often times given more money by the government or better housing. If a family illegally had another child, the family would be fined heavily. Children bornillegallycan not attend school and have a difficult time finding jobs, getting government licenses, or even getting married. Some have reported that the government would force abortions on families with more than one child. One of the major consequences of this policy was a dramatic increase in abortions and infanticides, especially of females. Female infanticide is linked directly to a global cultural trend that privileges males over females—baby boys are desired, especially if the family is only allowed one child. This specific focus on eliminating women is called gendercide.Half the Sky, written by Nicholas Kristof and Sheryl WuDunn, documents global gendercide and what is being done to combat this problem.

After the two great world wars, theUnited Nations Population Commissionand theInternational Planned Parenthood Federationbegan to advocate for more global population control. Many groups who advocate for population control focus on:

  • Changing cultural attitudes that keep population rates high (or low)
  • Providing contraception to LDCs
  • Helping countries study population trends by improving census counts
  • Empowering women and emphasizing gender equality

It is believed that worldwide, over 60 percent of women between ages 15-49 use some form of contraception. This varies regionally. In the United States contraception use is at nearly 75 percent, whereas in Africa it is around 30 percent. The generalconsensustoday is that the focus on population planning should be on gender equality and improving the social status of women around the world. This is the focus of theInternational Conference on Population and Development.

Religious organizations are also concerned with population growth; however, they focus on contraception issues and not strictly population growth. Some religions and political entities find contraception use immoral which has influenced some governments to make the access to them and useof them illegal.


Riebeek,H. (2005, March 28). The Rising Cost of Natural Hazards : Feature Articles. Retrieved from

Top Articles
Latest Posts
Article information

Author: Rob Wisoky

Last Updated: 12/06/2022

Views: 6054

Rating: 4.8 / 5 (48 voted)

Reviews: 95% of readers found this page helpful

Author information

Name: Rob Wisoky

Birthday: 1994-09-30

Address: 5789 Michel Vista, West Domenic, OR 80464-9452

Phone: +97313824072371

Job: Education Orchestrator

Hobby: Lockpicking, Crocheting, Baton twirling, Video gaming, Jogging, Whittling, Model building

Introduction: My name is Rob Wisoky, I am a smiling, helpful, encouraging, zealous, energetic, faithful, fantastic person who loves writing and wants to share my knowledge and understanding with you.