Glencoe Earth Science

HURRICANES!

Introduction

In this WebQuest, students do some Internet research on hurricanes. They learn about tropical cyclones and types of tropical cyclones, such as typhoons and hurricanes. They learn about the environmental conditions that result in tropical depressions, tropical storms, and hurricanes. They discover the destructive power of hurricanes by examining the statistics of the worst hurricanes of the last 100 years. They also find out about the Saffir-Simpson scale for classifying hurricanes. Finally, they answer some questions about hurricanes based on their Internet research.

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Task

While students are doing their Internet research, they will try to answer the set of questions given. Each web site has some of the answers to the questions, but several of the questions require information from two or more of the web sites. Students should be able to compile information to answer the questions as they read through each web site. Several of the web sites listed have comprehensive information about hurricanes. However, students should be encouraged to look at every web site, even if they think they have already answered most of the questions from just two or three web sites.

Objectives

• Define the following terms: hurricane, typhoon, tropical cyclone, tropical depression, and tropical storm.
  
  
• Identify the environmental conditions that give rise to tropical cyclones.
  
  
• List and describe the parts of a hurricane.
  
  
• Research the scale used to classify hurricanes and identify the most destructive hurricanes of the last 100 years.

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Resources

Students will use the Internet links given to find out all about hurricanes. They will learn about the relationships among tropical cyclones, tropical depressions, tropical storms, typhoons, and hurricanes. They will find out more about the environmental conditions that generate tropical cyclones. Students will also learn about the destructive power of hurricanes and about the worst hurricanes of the last 100 years.

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Time

1 class period for Internet research and answering the set of questions

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Process

As students progress through the list of web sites, you may help them to focus on what they need to know to answer the questions given. Several of the web sites have many links to other web sites. If time allows, you may want to allow students to explore this subject further.

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Evaluation

You may assign 10 points to each of the following questions for a total of 100 possible points. The answers to the questions are given below. You may rate the answers to each question by the following scale: Excellent – 9-10 points; Very Good – 7-8 points; Good – 5-6 points; Satisfactory – 3-4 points; Poor – 1-2 points; and Unsatisfactory – 0 points.

Questions about Hurricanes!

1. A tropical cyclone is the name for a non-frontal low-pressure system over tropical or subtropical waters with organized convection (thunderstorm activity) and definite cyclonic surface wind circulation. A tropical cyclone may be called a hurricane or a typhoon depending upon its location.
   
   
2. The ocean temperature must be warmer than 26.5ºC (81ºF); the relative humidity must be high; and there must be wind shear (change in the wind speed or direction with increasing altitude).
   
   
3. warm ocean water
   
   
4. The first stage is a tropical depression, when thunderstorms organize and winds near the center are a constant 20-34 knots (23-39 mph). The second stage is a tropical storm, when a tropical depression intensifies, and the maximum sustained winds are 35-64 knots (39-73 mph); at this stage the storm may be given a name and it becomes more organized and circular. The third stage is a hurricane, in which a tropical storm reaches wind speeds of 64 knots (74 mph) and a pronounced rotation develops around the central core of the storm.
   
   
5. the eye, the eye wall, and the spiral rain bands
   
   
6. The Saffir-Simpson scale is a scale that measures the intensity of a hurricane. It extends from a category 1 to a category 5, with 5 being the most intense storm. A category 4 hurricane has winds up to 131-155 mph.
   
   
7. A hurricane can be several hundred miles in diameter; an eye may be 20 miles in diameter.
   
   
8. The worst hurricane in the United States hit Galveston, Texas, in August-September, 1900. Approximately 8,000 people died in the storm.
   
   
9. The worst hurricane in the world occurred in Bangladesh in November 1970. Nearly 300,000 people died in the storm.
   

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Conclusion

Using information gathered from the Internet, students should be able to answer the questions given about hurricanes. Students should be able to draw some conclusions about the destructive power of hurricanes. Some students may be surprised to learn how many people died over the last 100 years as a result of hurricanes and other tropical storms. Ask students if they think that the use of satellite imagery and other modern tools to predict hurricanes has helped to reduce related death and destruction. Students should be able to suggest that prediction helps reduce deaths because people can prepare and/or move out of the path of the hurricane, but cannot reduce destruction much as it is a result of high winds produced in a tropical cyclone.

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