Download Foundations of Social Studies GEOGRAPHY

Foundations of Social Studies
GEOGRAPHY
NATURAL HAZARDS AND DISASTERS
Natural hazards are severe climate, geologic and astrologic events which happen naturally. A natural
hazard becomes a natural disaster when it destroys lives or livelihoods of people. Natural disasters can
happen in all parts of the world, but some regions tend to have more natural hazards than others.
Natural disasters range widely in size and intensity and experts have created different systems to
measure them.
As better technology has been developed, measuring and predicting some natural disasters has
become much easier. For example, today experts in the US can warn people as much as 5 days in
advance of a hurricane. But most natural hazards remain very difficult to predict. Likewise, the
population of the earth is growing so quickly that more and more people live in areas with high
natural hazard risks. Many less-developed nations have very little or no money for natural disaster
prediction and warning systems.
Geologic Hazards
Geologic hazards are caused by the movement in the earth's plates. These events happen at or below
the surface of the earth, but can have consequences that reach all the way into the highest parts of
the atmosphere:
 Volcanoes occur when molten rock comes to the surface of the earth. Some volcanoes erupt
very violently and very suddenly, like Mount St. Helens in Washington in 1980. But others erupt
more slowly, like the shield volcanoes that make up the Hawaiian Islands. Most volcanoes are
located along the Ring of Fire, a circle of plate boundaries in the Pacific Ocean.
 Earthquakes are sudden motions in the earth caused when the earth's plates move and
release energy. Most of the world's earthquakes occur along the Ring of Fire, similar to the
volcanoes.
 Landslides occur when large amounts of soil or rock shift on the surface of the earth.
 Avalanches are similar to landslides, but involve snow and ice.
 Tsunamis are giant waves in the ocean caused by earthquakes, volcanoes, landslides or
meteorites.
Weather and Climate Hazards
Natural hazards caused by extremes in temperature, precipitation or wind are called weather and
climate hazards:
 Floods can develop slowly or happen very quickly. Floods can be caused by many factors, both
natural and man-made. Extreme amounts of rain, dams breaking, deforestation, or rising sea
levels all can cause floods.
 Drought is a long period of little or no rainfall. Droughts can cause water shortages, crop
failures, and animals we rely on for food to die. Some experts argue that as global
temperatures continue to rise, humans will experience more frequent, longer and more severe
droughts.
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Hurricanes are types of tropical storms that form in the Southern Atlantic Ocean. Severe
thunderstorms tend to accompany hurricanes. The coasts of the Gulf of Mexico and the
Atlantic Ocean have the biggest hazard of hurricanes.
Tornadoes are the most violent storms in nature. They begin in powerful thunderstorms as a
rotating funnel-shaped cloud that reaches from the storm to the ground. Tornadoes are very
difficult to predict with accuracy, and they can move very quickly. Because of this, tornadoes
are extremely dangerous. In the United States, tornadoes occur most frequently in 'Tornado
Alley', a region in the Midwest stretching from South Dakota and Minnesota in the North, to
Texas and Oklahoma in the south.
Extreme heat, extreme cold, blizzards, thunderstorms and lightning are all types of weather
and climate hazards.
Astrologic Hazards
Astrologic hazards are caused by events in space, beyond the earth's atmosphere. The worst astrologic
disasters have been catastrophic to living things on earth—many experts theorize that an asteroid
collision led to the extinction of the dinosaurs:
 Space weather can disrupt or damage some of the technology we use on earth. Extreme
amounts of radiation released from the sun can damage important infrastructures like the
electrical grid and information technologies.
 Meteorites can impact the earth's atmosphere or even the earth's surface. The larger the
meteorite, the greater the amount of energy is released in the impact.
Health disasters
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Epidemics. Disease is a natural hazard that can be enhanced by human activities. People living
near each other in dense population clusters, people traveling to remote locations and
cultures, and the types of choices people make about food and health can all increase the
hazard of diseases. The large-scale spread of a disease is called an epidemic.
Wildfires
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Wildfires are uncontrolled fires burning in unsettled areas. Wildfires can have many different
causes like drought, extreme heat, forest management, lightning, astrologic hazards and
volcanic hazards. They become disasters when they spread, out of control, into settled areas
and threaten lives and property.
Natural Disasters vs. Man-made Disasters
Some experts argue that large man-made disasters like the nuclear meltdowns or the Dust Bowl
disaster in the United States in the 1930s are natural disasters. They argue this because, although
these disasters were caused by the activities of humans, they had enormous natural consequences.
As humans have more and greater effects on the atmosphere and surface of the earth, the line
between man-made and natural disasters will blur. Climate change, rising sea levels, deforestation and
other events can be argued to have been caused by human activities.
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