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What Are Natural Disasters?

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Presentation on theme: "What Are Natural Disasters?"— Presentation transcript:

1 What Are Natural Disasters?

2 The world is always changing.
Natural disasters are changes which are so great they may cause damage to the shape of the land or the lives of people and other things. Great changes happen deep inside the Earth and on its surface. The changes on the outer part of the Earth happen because of different kinds of weather

3 What Are Natural Disasters?
Volcanoes Earthquakes Hurricanes Tornados Floods Tsunami Drought Wildfires

4 Volcanoes A volcanic eruption is the spurting out of gases and hot lava from an opening in the Earth’s crust. Pressure from deep inside the Earth forces ash, gas and molten rock to the surface.

5 Earthquake An Earthquake is a violent shaking of the ground. Sometimes it is so strong that the ground splits apart. When parts of the Earth called plates move against each other, giant shock waves move upwards toward the surface causing the Earthquake.

6 Hurricane are severe tropical storms that form in the southern Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and in the eastern Pacific Ocean. Hurricanes gather heat and energy through contact with warm ocean waters. Evaporation from the seawater increases their power.

7 Tornadoes are nature’s most violent storms. Tornadoes must always be taken seriously. Tornadoes can be very dangerous -- sometimes even deadly. They come from powerful thunderstorms and appear as rotating, funnel-shaped clouds. Tornado winds can reach 300 miles per hour.

8 Floods A flood is caused by an overflow of water which covers land that is usually dry. Floods are caused by heavy rain or by snow melting and rivers burst their banks and over flow. Coastal floods are caused by high tides, a rise in sea level, storm waves or tsunami.

9 Tsunami tsunami (pronounced soo-nahm-ee) is a series of huge waves that happen after an undersea disturbance, such as an earthquake or volcano eruption. (Tsunami is from the Japanese word for harbor wave.) The waves travel in all directions from the area of disturbance, much like the ripples that happen after throwing a rock. The waves may travel in the open sea as fast as 450 miles per hour.

10 Drought A drought is the lack of rain for a long period of time.
In 1968 a drought began in Africa. Children born during this year were five years old before rain fell again.

11 Wildfire Fires can burn out of control in areas of forest.
Fires are caused by lightning, sparks of electricity or careless people. Winds may blow a fire to areas where people live.


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