strength of tropical cyclones are also difficult to predict, even with computer assistance. Three-day forecasts are still off by an average of 280 kilometers. Forecasters do know that storms are often energized where ocean water is deep and warm, that high waves tend to reduce their force, and that when tropical cyclones move over land, they begin to die.
Long-term forecasts are poor; small differences in the combination of weather factors lead to very different storms. More accurate forecasting could help people decide to evacuate when a storm is on the way. \says storm researcher Sharan Majumdar. \science. That's the only way to get people to trust the warnings.\ Multiple Choice. Question 1. What is Firinga? Question 2. \the word condenses mean? Question 3. Which step comes first in the process of storm formation? Question 4. \direction and strength of tropical storms are difficult to predict, even with computer assistance.\ Question 5. Which of the following is one of the main ideas of the passage? Script
A tornado is a column of quickly rotating air that reaches from the clouds all the way to the ground below. Like their big sisters, the tropical cyclones, tornadoes are formed in upward-moving, warm and humid air. Also like tropical cyclones, tornadoes produce strong winds that rotate around a center of low pressure. Although tornadoes are much smaller than tropical cyclones -- the largest being about four kilometers across -- their winds can be as fast as 480 kph. You can't always see a tornado, but it becomes a frightening dark color when it pulls dirt upward from the ground. The power of tornadoes is expressed on a scale from F0 to F5. An F0, with wind speeds up to 110 kph, might damage signs, while a tornado with wind speeds of about 420 to 480 kph can blow houses over, qualifying as an F5.
Many tornadoes develop from dangerous, long-lived thunderstorms called supercells that are between 10 and 16 kilometers across. Supercells can create tornadoes one after another in a repeating cycle, in which a new tornado forms where the previous one dies.
In the United States tornadoes are to blame for a number of deaths every year, sometimes totaling in the hundreds. The National Weather Service attempts to forecast tornadoes and warns people when they start to form. They advise people to stay in a basement, closet, or bathroom. However, professional storm researchers sometimes approach within just meters of tornados to collect information using a(n) combination of methods that include computers, video cameras, and their own observations. The 1996 movie Twister was about such brave researchers.
Viewing
Birth of a Hurricane Answer Key Before You View
A. 1. catastrophic 2. destruction 3. tropical 4. condensation B. Answers will vary. Viewing Comprehension
A. 1) 6:10 2) 29th 3) 4 4) everything
B. c, e, h, g, a, i, d, f, b C. 1. T 2. F 3. T 4. T 5. F After You View
A. 1. combination 2. circumstances 3. humid 4. upward 5. cycle 6. rotate 7. energized 8. qualified 9. exposed 10. widespread B. Answers will vary. Script
Birth of a Hurricane Narrator:
At 6:10 a.m. on Monday, August 29th, a Category 4 hurricane named Katrina reached the Louisiana coast, destroying almost everything in its path. What were the circumstances that led to this catastrophic storm?
Five days earlier, on August 24th, the temperature off the coast of the Bahamas was almost 30 degrees Celsius. Humid air was rising upward from the warm waters of the ocean. As the warm, wet air rose, it condensed and formed a system of thunderstorms. This condensation releases heat, which warms the cool air of the atmosphere, causing it to rise. As that air rises, more warm air from the ocean takes its place. This creates a cycle which continuously moves heat from the ocean to the atmosphere. The movement creates a pattern of wind that begins to move around and forms a center. Occasionally, one such rotating wheel of thunderstorms gathers strength, feeding on the combination of moisture and heat. When the winds of Tropical Depression 12 reached almost 63 kilometers an hour, Tropical Storm Katrina was born.
Most extreme tropical storms happen in the open sea, where they do little harm. Some, like Katrina, arrive on the land. Katrina moved slowly -- sometimes as slow as nine kilometers per hour -- but she was getting stronger and heading toward Florida.
Katrina only qualified as a Category 1 hurricane when she touched the Florida coast and moved out into the Gulf of Mexico. In the Gulf, the water reached a very warm 30 degrees Centigrade. These warmer waters caused Katrina to become stronger and more energized.
After three days moving over the warm waters of the Gulf, Katrina grew to a Category 5 hurricane, with winds of more than 250 kilometers an hour. Before arriving on land, Katrina was a Category 4 hurricane, but that was still extremely strong. With powerful winds and a giant wave, or storm surge, over six meters high, Katrina was still the most destructive storm to hit the area in 36 years. The danger could no longer be ignored. Once over land, the states of Louisiana and Mississippi became exposed to Katrina's destructive winds. At the same time, now that it was away from the warm waters of the Gulf, the storm began to weaken. Twelve hours after reaching land, Katrina was no longer a hurricane, with top winds of just over 100 kilometers an hour. A few short hours later, the only thing left of Katrina was the widespread destruction she had left behind.
Writing
Answer Key
A. 1. It is about the cause of the flooding of New Orleans in 2005, the aftermath, and the city's future.
2. It is how tropical cyclones (hurricanes or typhoons) are formed, their dangers, and difficulties in forecasting them.
3. It is about the formation of Hurricane Katrina and how it developed into one of the most
destructive storms in U.S. history is explained.
B. The birth of Hurricane Katrina is worth studying. We've learned about the causes, speed and route of Katrina, so those factors of future hurricanes may be watched and predicted well before they cause any serious destruction whether on land or at sea. It took days for hurricanes to gather speed and strength that is enough to do much harm, so forecasts could be updated to warn people on their possible routes and evacuation would be more efficient in future.
Unit 6 Reef Encounters Warming Up Answer Key
1. Answers will vary, but should be supported by reasons to show that students have properly considered the questions.
2. Damage has been caused by numerous kinds of pollution, by over-fishing, and by physically hurting coral reefs and the ocean floor. In addition, global warming is having a negative effect on marine habitats.
3. Some fish, sharks, and jellyfish are dangerous. Some kinds of coral sting as well. Listening
6A Coral Reefs Answer Key
Before You Listen A. 1. F 2. T 3. F 4. T
B. How coral is formed, Coral reef wildlife, and Problems affecting reefs Listening Comprehension A. 1. b 2. c 3. b 4. c 5. b
B. Sample answers: 1. fish as possible 2. building material 3. liquid cyanide 4. the aquarium market 5. turn white After You Listen
A. 1. shallow water 2. survive without sunlight 3. at the bottom 4. method of fishing 5. weighted nets 6. negative effect 7. destroy all the coral 8. conservation of these ecosystems 9. prevents bottom trawling 10. generations of sea life B. 1. b 2. a 3. a 4. b 5. a
C. Sample answers: 1. shallow: the opposite of deep; negative: the opposite of positive; conservation: taking care of the environment; creatures: living things that are not plants; generations: groups of living things of similar age 2. Answers will vary, but should be convincing to show that students have properly considered the question. Script
Cities Beneath the Sea
Coral polyps can truly be called the animals that helped make the world. For uncounted generations, trillions upon trillions of coral polyps have built structures called reefs, larger in scale than those of any other living beings, including humans. The stone-like material created by these tiny animals becomes limestone, a prized building material that was used to construct the Great Pyramids of Egypt.
Huge deposits of limestone exist underground, beneath the ocean, in islands, and in mountains.
Limestone has been used in the construction of countless churches, castles, train stations, and banks, and crushed limestone is a major ingredient of cement. A Variety of Life
Living coral reefs are remarkable %undersea ecosystems thrive in the warm, shallow oceans near the equator. Among the world's most colorful places, coral reefs are full of brilliantly colored fish and coral covered in wonderful patterns. Reef fish are an important food source for humans, and make up a significant percentage of the global fish catch. Threats to Coral Reefs
In recent years, various factors have threatened coral reefs and the life that depends on them as their home. Blast fishing is an illegal fishing method which involves setting off bombs in the water to kill as many fish as possible. Its negative effects on a reef are significant; it kills most living things and causes great damage to the reef's structure.
Fishing with liquid cyanide, a very dangerous and deadly material, is another threat to reef ecosystems, particularly in the Philippines. Fishermen release liquid cyanide into the reef and collect the stunned fish, which are then sold for big money to the aquarium market, or for consumption in restaurants. The fishermen often break apart the reef to look for hiding fish. The cyanide also kills large numbers of coral polyps, leaving large areas of the reef dead.
Reefs are also damaged when coral is taken for building material, jewelry, or aquarium ornaments. Water pollution also results in damage. In addition, the recent warming of the oceans has caused areas of many reefs to turn white. Biologists are concerned that coral may be negatively impacted by further warming. Reasons for Hope
Threats to coral reefs are serious, but there is reason to hope that they will manage to survive. If we take steps toward coral reef conservation, it is likely that these tiny creatures, which have survived natural threats for millions of years, will be able to rebuild the damaged reefs that so many ocean animals and plants depend on. A. Multiple Choice. Question 1. What is this passage mainly about? Question 2. Which statement about coral reefs is NOT true? Question 3. What is the material commonly called coral made of? Question 4. Why does the author mention the selling price of reef fish? Question 5. Which of these is one of the main ideas of the passage?
B. Completion. Have students complete Activity B. Then, have students check answers as a class. Remind students that their answers must be three words or less. Script
Not all coral is found in warm, shallow water. Some coral polyps can even survive without sunlight in the deep, cold waters at the bottom of the northern Pacific Ocean. But they are not safe from the method of fishing known as bottom trawling. Bottom trawlers pull heavy, weighted nets across the ocean floor. These nets have a very negative effect on deep sea coral. Though trying to catch fish, these nets destroy all the coral and the coral ecosystems in their way. The conservation of these ecosystems is important for the future of many of the ocean's plants and creatures. A new U.S. law prevents bottom trawling in over a million square kilometers of ocean off its Pacific coast. Keeping these ecosystems healthy is important for future generations of sea
life, as well as for the people who will depend on that life.
6B The Truth about Sharks Answer Key
Before You Listen A. 1. a type of fish 2. length 3. teeth 4. dead things 5. nets B. Some common ideas about sharks are not true. Listening Comprehension A. 1. c 2. a 3. b 4. c 5. b B. a. F b. T c. T d. F e. F After You Listen
A. 1. a feeling of horror 2. confusion about the true nature of sharks 3. quite inaccurate 4. bite humans 5. factual information B. 1. comprehend 2. arranged 3. hypothesize 4. gather 5. categorized C. 1. Answers will vary. 2. Answers will vary, but must be convincing. Script
Shark Attack
Craig Rogers was sitting on his surfboard, scanning the distance for his next wave, when his board suddenly stopped moving. He looked down and was terrified to see a great white shark biting the front of his board. \could have touched its eye with my elbow,\says Craig. The shark had surfaced so quietly he hadn't heard a thing. In his horror and confusion, he waved his arms and accidentally cut two of his fingers on the shark's teeth. He then slid off the opposite side of his surfboard into the water. Then, with Craig in the water and blood flowing from his fingers, the five-meter-long shark simply swam away, disappearing into the water below.
Although sharks are often categorized as killers that hunt and eat as many humans as they can, this is factually inaccurate. Sharks very rarely kill humans. A person has a greater chance of being struck by lightning or drowning in a bath than of being killed by a shark. Only 74 people have been reported killed by great whites in the last century. But great white sharks can reach six meters in length and weigh 2,200 kilograms or more. With frightening jaws that can hold up to 3,000 teeth arranged in several rows, they could very easily kill and eat a helpless human in the water. Why is it, then, that most people survive attacks by great whites? Shark researchers are trying to comprehend the reasons that allow people to escape without being eaten.
The most common explanation is that great whites don't see well. It has been thought that they mistake people for the seals or sea lions which make up a large part of their diet. There is reason to doubt this, however. Recent information shows that great whites can actually see very well. Also, when attacking seals, great whites shoot up to the surface and bite with great force. When approaching humans, however, they most often move in slowly and bite less hard. They soon discover that humans are not a high-fat meal. \Aidan Martin, director of ReefQuest Center for Shark Research.
Shark researchers like Martin hypothesize that great whites are actually curious animals that like to investigate things. It's possible that they use their bite not only to kill and eat, but also to gather information. Although such an experience is unlucky for people like Craig Rogers, when sharks bite surfboards or other objects or people, they are likely just trying to learn what they