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Background InformationIn July1990, an 18-year-old male was struck and injured by lightning while attending a concert at an amphitheater 14 miles south of Birmingham, Alabama. While chatting with a friend near a mulberry tree, a 35-year-old woman was knocked to the ground by lightning in San Manuel, Arizona. She had first and second degree burns, coins in her pockets were partially melted, and rivets on her jeans were also melted. A 17-year-old girl was shocked and burned while talking on the telephone when lightning struck near the back of her house in Canton, Illinois. When lightning struck a tree north of Kokomo, Indiana, it killed one person and injured four people who were seated in metal chairs under the tree.Lightning is a sudden electrical discharge that is formed in a way similar to the spark that flashes when you touch an object after walking across a carpet. In lightning, electrons flow between the oppositely charged parts of a cumulus cloud or between the clouds and the ground. As a thunderstorm passes overhead, the ground below becomes positively charged compared to the bottom of the cloud that is negatively charged. Since opposite charges attract one another, the stage is set for the huge outdoor spark that we call lightning. During 1990 there were 1132 tornados in 181 days, which killed 53 people and injured 11. A tornado is a wildly spinning column of air, called a vortex, that extends downward from a cumulonimbus cloud and moves along the ground. Low air pressure within the vortex causes air near the Earth's surface to rush into the vortex carrying dust and debris. Winds that can reach well over 200 miles per hour circulate counterclockwise around the center of the tornado. Known as the most powerful storms in the world, tornados can destroy almost anything in their paths. Although most people realize that both lightning and tornados are spawned by thunderstorms, few people realize that lightning causes more deaths than tornados. One explanation for this misconception comes from our method of reporting tragedies. Lightning deaths tend to occur singly with little property damage and, therefore, are deemed less news worthy. On the other hand, multiple deaths and extensive property damage from a tornado frequently make headline news. Furthermore, lightning deaths often occur in weak thunderstorms when people remain outside, not during severe thunderstorms when people take shelter. In the procedure for this activity we will look at deaths caused by lightning and tornados to see if there is a relationship. |
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Procedure
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Questions
Print at 92% for use in this Activity. |
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Conclusionsat the top of this web page and write your conclusions here. 
Figure 3.3. Conclusions Sheet Print at 92% for use in this Activity. |
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Safety Information
Tornado SafetyLightning Safety |
