Hurricanes: An introduction
The storm season is here again. Tropical storm Nock-Ten just hit Thanh Hoa and Nghe An provinces at the end of last month (see http://www.tuoitrenews.vn/cmlink/tuoitrenews/society/one-killed-in-tropical-storm-in-central-vietnam-1.38876). This time, luckily, there were few casualties. But how and why do these storms form? What makes them so dangerous? In this article and accompanying video we look at how hurricanes are formed and how they behave.
Video: Hurricanes
LISTENING STRATEGY: LISTENING FOR NUMBERS.
Watch the video. Listen for and note down the numbers.
1. The energy released by an average hurricane in one day equals about _________small atomic bombs.
2. The sun heats the ocean to a temperature of _________ degrees.
3. A tropical storm has a wind speed of more than ____________ miles per hour.
4. Officially, a hurricane has a wind speed of ________miles per hour or more.
5. Bands of rain are up to _______miles long.
6. Wind speeds in the eye wall can reach __________ miles per hour.
7. A hurricane can reach _______miles in diameter.
8. Some hurricanes are _______miles high.
9. _________people were killed by hurricanes in the 20th century.
10. Hurricane Andrew caused ______________billion dollars of damage.
PRE-READING:
Look at the title and predict the main ideas of the article. Then, write down three wh-questions about the text.
Ex: How does a hurricane form?
WHILE READING:
Set a time limit to read this article. An average reader can read at the speed of 250 words per minute. Note down your reading speed regularly to check your progress.
SKIMMING:
Within the time limit, read and summarize the main ideas of the paragraphs in your own words. Do not worry about unfamiliar vocabulary.
Engines of Destruction
Hurricanes are giant, spiraling tropical storms that can pack wind speeds of over 160 miles (257 kilometers) an hour and unleash more than 2.4 trillion gallons (9 trillion liters) of rain a day. These same tropical storms are known as cyclones in the northern Indian Ocean and Bay of Bengal, and as typhoons in the western Pacific Ocean.
The Atlantic Ocean’s hurricane season peaks from mid-August to late October and averages five to six hurricanes per year.
Hurricanes begin as tropical disturbances in warm ocean waters with surface temperatures of at least 80 degrees Fahrenheit (26.5 degrees Celsius). These low pressure systems are fed by energy from the warm seas. If a storm achieves wind speeds of 38 miles (61 kilometers) an hour, it becomes known as a tropical depression. A tropical depression becomes a tropical storm, and is given a name, when its sustained wind speeds top 39 miles (63 kilometers) an hour. When a storm’s sustained wind speeds reach 74 miles (119 kilometers) an hour it becomes a hurricane and earns a category rating of 1 to 5 on the Saffir-Simpson scale.
Hurricanes are enormous heat engines that generate energy on a staggering scale. They draw heat from warm, moist ocean air and release it through condensation of water vapor in thunderstorms.
Hurricanes spin around a low-pressure center known as the “eye.” Sinking air makes this 20- to 30-mile-wide (32- to 48-kilometer-wide) area notoriously calm. But the eye is surrounded by a circular “eye wall” that hosts the storm’s strongest winds and rain.
These storms bring destruction ashore in many different ways. When a hurricane makes landfall it often produces a devastating storm surge that can reach 20 feet (6 meters) high and extend nearly 100 miles (161 kilometers). Ninety percent of all hurricane deaths result from storm surges.
A hurricane’s high winds are also destructive and may spawn tornadoes. Torrential rains cause further damage by spawning floods and landslides, which may occur many miles inland.
The best defense against a hurricane is an accurate forecast that gives people time to get out of its way. The National Hurricane Center issues hurricane watches for storms that may endanger communities, and hurricane warnings for storms that will make landfall within 24 hours.
Word count: 376 words
Source for the article and video: National Geographic:
SCANNING:
Use your notes to identify where you can find the answers to the questions you made in the pre-reading stage.
UNDERSTANDING THE TEXT: Explain the connections between the following:
1. hurricanes – cyclones – typhoons
2. tropical depression – tropical storm – hurricane
3. sinking air – eye – eye wall
4. storm surge – high winds – torrential rain
5. defense – forecasts
POST-READING:
Glossary:
Pay attention to how the word is combined with other words in context. Do not learn the meaning of the word without sentences. Vietnamese should be the last resort after you have tried all the learning strategies.
• Spiraling (adj): moving in a curve that goes round and round as it goes up or down (Di chuyển theo hình xoắn ốc)
• To pack (v): to have (Bao gồm)
• To unleash (v): to suddenly make something start happening which has a great effect (Gây ra, bung ra, giải phóng)
• Disturbance (n): something that interrupts what you are doing (Sự xáo trộn)
• Tropical disturbance: nhiễu loạn nhiệt đới
• Surface temperature (n): is the water temperature close to the upper layer of the ocean (Nhiệt độ trên bề mặt)
• Low pressure (n): a condition of the atmosphere in which the pressure is below average (Áp thấp)
• Sustained (adj): continuing for an extended period or without interruption (Được liên tục duy trì)
• Rating (n): a measurement of how popular, good, important etc someone or something is (Sự phân loại theo cấp độ)
• Saffir-Simpson scale (Proper noun): Name of a scale used to categorise how severe a storm is: thang bão Saffir-Simpson là thang phân loại bão được sử dụng nhiều nhất cho các xoáy thuận nhiệt đới ở Tây bán cầu có cường độ vượt quá cường độ của các áp thấp nhiệt đới và các trận bão nhiệt đới. Thang này chia các cơn bão thành 5 cấp được phân biệt theo cường độ sức gió kéo dài của nó.
• Staggering (adj): astonishing or deeply shocking (Gây kinh ngạc, làm sửng sốt)
• Storm surge (n): a rising of the sea as a result of wind and atmospheric pressure changes associated with a storm (Cơn sóng cồn)
• To spawn (v): produce: sinh ra, gây nên
• Tornado (n): an extremely violent storm consisting of air that spins very quickly and causes a lot of damage (Vòi rồng)
• Torrential (adj): falling in large amounts (Cuồn cuộn, xối xả)
• Torrential rain: mưa xối xả
• Landslide (n): a sudden fall of a lot of earth or rocks down a hill, cliff, or mountain (Lở đất, đá)
Collocations and expressions
• Make landfall: reach the land that you see or arrive at first after a journey: chạm đất liền
DEFINTIONS from:
Longman Active Study Dictionary
Grammar:
Look at the following sections of the article. Which verb is in active form? Which verb is in passive form? Can you explain why?
Hurricanes begin as tropical disturbances in warm ocean waters with surface temperatures of at least 80 degrees Fahrenheit (26.5 degrees Celsius). These low pressure systems are fed by energy from the warm seas.
Verbs in active form: begin
Verbs in passive form: are fed
Explanation: We switch between active and passive to change the subject of a sentence. Here we are describing the process of forming a hurricane. The storm which becomes the hurricane is therefore the subject of the process and occupies the subject position of the sentence. We can achieve this with the active form of ‘begin’. We need the passive form of ‘feed’ to keep the storm (low pressure systems) in the subject position.
Now review the grammar lesson PASSIVE VOICE on this webpage for further information.
Discussion and Writing:
Find a study friend to summarize your story. Try to use the vocabulary learned in the article in speaking and writing your summary.
Choose another natural disaster (e.g. volcanic eruption, earthquake). Do some research in English. Then write a paragraph to explain:
• what are its features
• how it is caused
• the effects it can have
Answers
Video: Listening for numbers
1. 500,000
2. 82
3. 39
4. 74
5. 300
6. 200
7. 500
8. 9
9. 45,000
10. 25 billion
Reading: Connections
1. They are different names for the same thing – hurricanes, as they are called in the Atlantic Ocean, are known as cyclones in the Indian Ocean and typhoons in the Pacific.
2. They are different classes of storm, based on wind speed:
a. tropical depression: 38 mph (61 km/h)
b. tropical storm: 39 – 73 mph (63 km/h – 118 km/h)
c. hurricane: 74 mph or more (119 km/h)
3. The eye is the centre of the storm. It is surrounded by the eye wall. The sinking air (air moving down) in the eye causes it to be calm. The eye wall, by contrast, is the most violent part of the storm.
4. These are all ways in which the hurricane causes damage. The storm surge is a big wave and causes the most deaths. High winds damage buildings and torrential rain causes floods and landslides.
5. The best defense, or protection, against hurricanes is to have accurate weather forecasts. These can then be used to warn people so they can move to safety.
This material is provided by the Australian Centre for Education and Training (ACET).
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