Explore on your own, Wind at Work (Pathfinder Edition)

EPaSArTctHiheFInNDcEeR EDITION

ON YOUR OWN

aWt Windork

By Beth Geiger

PATHFINDSEcRieEnacrteh
EDITION

It’s Time to
Explore on Your Own!

Good readers use multiple strategies as they
read on their own. Use the four key reading
comprehension strategies below:

1 Preview and
predict
• Look over the text.
• Form ideas about how the text is organized and what it says.
• C onfirm ideas about how the text is organized and what it says.

2 monitor and
fix up
• T hink about whether the text is making sense and how it relates to
what you know.
• I dentify comprehension problems and clear up the problems.

3 make
inferences
• Use what you know to figure out what is not said or shown directly.

4 sum
up
• Pull together the text’s big ideas.

Remember that you can choose different strategies at different
times to help you understand what you are reading.

aWt Windork

Pathfinder Edition

By Beth Geiger

Contents
2 Wind at Work
8 An Energy Adventure
12 Concept Check

aWt Windork

2

Windsurfing is a blast. It’s a lot like surfing,

but with a sail. Stand on your board. Wait for the wind to pick
up. Then hang on! The next thing you know, you’re tearing
across the cool water.

You may not have windsurfed before. Maybe you’ve flown
a kite. Or perhaps you’ve sailed in a sailboat. People have
used wind in different ways for thousands of years.

3

Air on the Move

What is wind? What causes it? Wind is just air
on the move. The sun causes it. When the sun
shines on land or water, the land or water heats

up. As air warms up, it becomes lighter. It
rises. Cooler air rushes in to fill the gap
where the warm air was. That rush is wind.

Earth swirls with wind all the time because
its surface heats up unevenly. Oceans, for
example, take longer to heat and cool than land.
This means that the ocean is usually a different
temperature than a sandy beach. The different
temperatures often cause it to be breezy at
the beach.

Different types of places, such as forests,
deserts, and prairies, also soak up heat from
the sun differently. They cool down at different
rates, too. Don’t forget about the cold places
at Earth’s top and bottom, and the warm area
around Earth’s middle. Air moves constantly
between all these hot and cold spots.

Some winds blow in a regular pattern across
thousands of miles. Other winds are local
and sudden, such as gusts in a thunderstorm.
Mountains, islands, and even tall buildings affect
how wind moves. No wonder there are so many
types of wind. Gales and gusts, breezes and
puffs—those are just a few kinds of wind.

4

Invisible Force piece, wind can erase a whole mountain.
This process of wearing away is called
You can’t see wind. Yet you can see its weathering. It happens over a long time.
handiwork. Have you seen a tree branch
swaying? That’s wind. Ever watch an Bit by bit, over millions of years, wind
umbrella blow inside out? Wind again. carves rocks into cool new shapes. What
about all those loose pieces of rock? Wind
Wind does more than just blow piles them into graceful sand dunes. Not
umbrellas. It sculpts rocks and landscapes bad for an invisible force.
by blowing pieces of loose rock off of larger
rocks. All those pieces add up. Piece by tiny

Blown away. the shapes of these
rock formations in Monument Valley,
Utah were made by wind. the wind
blew away small pieces of the rock.

5

Predictable Patterns. the Vikings Wind Power
used trade winds to sail ships like these.
People don’t need to use wind to cross the
Fast Lanes ocean anymore. They have airplanes for that.
Still, wind can help in other ways. One way is
Long before people used wind to have fun by making electricity.
at the beach, they used wind to get places.
Ancient Egyptians hoisted sails to travel up The Horse Hollow wind farm in Texas
and down the Nile River. The Polynesians doesn’t grow wheat or corn. Instead, it
set sail across the Pacific Ocean at least has hundreds of steel wind turbines. The
3,000 years ago. Wind blew the Vikings as turbines are like huge windmills. Each
they explored the world. tower is taller than a 20-story building. The
turbines make a weird hum. The sound is
Early sailors were smart. They noticed the blades spinning in the steady wind.
that Earth’s major winds blew in predictable
patterns. Studying these patterns helped Wind, after all, is energy. It’s clean and
sailors plan their voyages. renewable energy, too. This means it
doesn’t pollute the environment or use up
Some of Earth’s most reliable winds blow natural resources. Wind makes the turbines
west near the equator. That’s the imaginary spin. The spinning turns a generator. Then
line around the middle of the planet. Trading the generator makes electricity.
ships used the force of these winds to send
goods around the world. These helpful winds Wind farms work best in open spaces
are called trade winds. You could call trade where nothing gets in the wind’s way. So far,
winds the original fast lanes. the United States snags enough breeze to
power about 4.5 million homes. That’s only
People still sail boats today. Modern about 1 percent of the electricity we need.
sailing, however, is mostly for sport. Even Slowly, though, the role of wind power is
so, today’s sailors still rely on the same wind growing. More wind farms seem to crop up
patterns that pushed trade ships hundreds every year.
of years ago.

6

Windy harvest. Wind farms like
this one don’t grow things in the
ground. Instead they create electricity.

World of Wind

From gentle breezes to strong gusts, wind
is everywhere. It can sculpt mountains. It
can make a day in the sun a blast. Long
ago, wind carried explorers to new places.
Now it helps light cities and makes sports
like windsurfing a thrill.

The next time you are just shooting the
breeze, think about the many ways wind
changes our world.

first Spin. the first wind turbine Wordwise
was built in 1888.
renewable energy: energy from a

source, such as wind, that does
not get used up

trade winds: constant winds that blow

toward the equator

wind farm: a large group of wind

turbines

wind turbine: windmill that makes

electricity

7

An Energy Adventure

Whop. Whop. Whop. The blades of Big Rigs
the helicopter slice the air. There is no
land in sight. All you can see is the The platform is a maze of steel. There are
vast Gulf of Mexico. drill rigs and pipes. There are ladders and
cranes. Still, you can only see part of it.
Then something appears ahead. It Under the water, the platform is attached
looks like a cross between a factory to the ocean bottom by a tower taller than a
and an island. It’s an offshore oil skyscraper! Other platforms are in water too
platform. The platform is there to deep for towers. Instead, they are moored to
pump oil from deep below the ocean the bottom with cables.
floor. It is as big as two football fields.
It towers above the water.

The helicopter lands. Wow, the
platform is noisy! You put on a hard
hat and earplugs. Now you are ready
for a tour.

Cozy Quarters. Most bunk rooms When people come to work on a
are made for four people. platform, they stay for two weeks. They
need to stay that long because the oil rig is
so far from land. The crew shows you where
they live. They sleep in bunk beds. They have
a cafeteria and a gym. There is even a movie
theater!

Altogether there are over 4,000 offshore
platforms just near the United States. Many
are in the Gulf of Mexico. Some are in the
Pacific Ocean, near California, or the cold
waters off Alaska. Many more platforms are
located near Europe, Asia, and Africa.

8

Parts of an Oil Platform crane
bunk rooms and
drill rig living space

heLlicaobpetleTr Klanding pad

platform

Building these monster platforms is a have to be safe for workers. The platforms,
big job. They must be designed exactly and the towers that support them, are
right. They must withstand ocean built on land. When they are ready, ships
currents, waves, and hurricanes. They tow them out to sea.

Ocean Reserves.
About 27% of oil in the
United States comes from
offshore platforms.

9

Deep Subject

From the platform, pipes extend deep
into the ocean floor. On most platforms,
the pipes bring oil or natural gas to the
surface. On other platforms, the pipes
are for drilling deeper to find more oil.
In some places, oil may be 20,000 feet or
more below the bottom of the ocean.

How did the oil and gas get there?
Millions of years ago, tiny sea animals
and plants died. Their remains settled on
the ocean floor. Slowly, heat and pressure
turned the remains into oil. The oil
seeped into tiny gaps in rock, like water in
a sponge. Then, thousands of feet of silt,
clay, or even salt covered the rock. The oil
was trapped. Forming and trapping the oil
took a lot of heat and pressure. It took a
lot of time, too.

Later, geologists used special methods
to find the buried oil and gas. For
example, they studied seismic waves.
Seismic waves are pulses of energy sent
deep into Earth. The waves bounce back
in patterns. The patterns can reveal where
oil is trapped.

Oil and natural gas can be used to
make energy. They are nonrenewable
forms of energy. That means we use them
up before more can be made.

10

Balancing Act

With all that steel and machinery, you
wouldn’t expect to see much nature nearby.
Surprise. The platform’s underwater
structure can act like a natural reef. Often
when a platform is built, coral and fish
move in.

There is always a risk that oil might
leak into the ocean. The companies
that own the platforms try to keep that
from happening. They are using new
technologies to try to keep leaks and
accidents from happening.

Your tour is almost over. You head back
towards the helicopter.

A beautiful sunset warms the sky. The
ocean is calm. You think about being
home. Then you think about where the
gasoline in your car came from—maybe
right here!

11

ConCePt CheCk Energy Resources

Let’s see what you learned about
our world’s energy resources.

1 Explain what causes wind.
2 How does wind make

electricity?
3 Why is wind a good source of

energy?
4 Explain why oil and gas are

found so deep.
5 Would you want to work on

an offshore oil platform?
Why or why not?

Index Acknowledgments
Grateful acknowledgment is given to the authors, artists, photographers,
air  4 museums, publishers, and agents for permission to reprint copyrighted material.
breeze  4, 6–7 Every effort has been made to secure the appropriate permission. If any omissions
electricity  6, 12 have been made or if corrections are required, please contact the Publisher.
generator  6
nonrenewable energy  10 Photographic Credits
ocean  4, 6, 8–11 Cover Robert Fuladi/Shutterstock; 2-3 DigitalStock/Corbis; 4 Michael William/
offshore oil platform  8 Shutterstock; 5 John Foxx Images/Imagestate; 6 Ted Spiegel/National
oil   8–10 Geographic Image Collection; 6-7 PhotoDisc/Getty Images; 7 Pinchuk Alexey/
pattern  4, 6 Shutterstock; 8 STR/AFP/Getty Images; 8-9 Paul Andrew Lawrence/Alamy
renewable energy  6 Images; 9 Paul Andrew Lawrence/Alamy Images, Cameron Davidson/Alamy
temperature  4 Images; 10-11 Flip Nicklin/Minden Pictures/National Geographic Image
trade winds  6–7 Collection; 12 viki2win/Shutterstock.
weathering  5
wind  3–7, 12 Neither the Publisher nor the authors shall be liable for any damage that may
wind farm  6 be caused or sustained or result from conducting any of the activities in this
wind turbine  6–7 publication without specifically following instructions, undertaking the activities
without proper supervision, or failing to comply with the cautions contained
herein.

Program Authors
Kathy Cabe Trundle, Ph.D., Associate Professor of Early Childhood Science
Education, The Ohio State University, Columbus, Ohio; Randy Bell, Ph.D.,
Associate Professor of Science Education, University of Virginia, Charlottesville,
Virginia; Malcolm B. Butler, Ph.D., Associate Professor of Science Education,
University of South Florida, St. Petersburg, Florida; Judith Sweeney Lederman,
Ph.D., Director of Teacher Education and Associate Professor of Science
Education, Department of Mathematics and Science Education, Illinois Institute of
Technology, Chicago, Illinois; David W. Moore, Ph.D., Professor of Education,
College of Teacher Education and Leadership, Arizona State University, Tempe,
Arizona

The National Geographic Society
John M. Fahey, Jr., President & Chief Executive Officer
Gilbert M. Grosvenor, Chairman of the Board

Copyright © 2011 The Hampton-Brown Company, Inc., a wholly owned
subsidiary of the National Geographic Society, publishing under the imprints
National Geographic School Publishing and Hampton-Brown.

All rights reserved. No part of this book may be reproduced or transmitted in
any form or by any means, electronic or mechanical, including photocopying,
recording, or by an information storage and retrieval system, without permission
in writing from the Publisher.

National Geographic and the Yellow Border are registered trademarks of the
National Geographic Society.

National Geographic School Publishing
Hampton-Brown
www.NGSP.com

Printed in the USA.
RR Donnelley, Johnson City, TN

ISBN-13: 978-0-7362-7769-3

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