Earth Science
and the Environment
This page intentionally left blank
Earth Science
and the Environment
FOURTH EDITION
GRAHAM R.THOMPSON, PHD
University of Montana
JONATHAN TURK, PHD
Australia • Brazil • Canada • Mexico • Singapore
Spain • United Kingdom • United States
Earth Science and the Environment, fourth edition
Graham R. Thompson and Jonathan Turk
Executive Editor: Peter Adams
Assistant Editor: Carol Benedict
Editorial Assistant: Anna Jarzab
Technology Project Manager: Samuel Subity
Marketing Manager: Kelley McAllister
Marketing Communications Manager: Nathaniel Bergson-Michelson
Content Project Manager: Belinda Krohmer
Creative Director: Rob Hugel
Art Director: Vernon Boes
Print Buyer: Becky Cross
Permissions Editor: Roberta Broyer
Production Service: Pre-Press Company, Inc.
Text Designer: Terri Wright
Art Editor: Lisa Torri
Photo Researcher: Terri Wright
Cover Images: Background Image – © Royalty-free Photodisc Red/
Getty Images
Inset globe – NASA/Goddard Space Flight Center, The SeaWiFS Project
and ORBIMAGE, Scientific Visualization Studio, Landsat-7 Project,
and USGS EROS Data Center.
Atmosphere – NOAA
Biosphere – Royalty-Free/Corbis
Hydrosphere – © Royalty-free Image Source Limited/Jupiter Images
Geosphere – VEER Christopher Talbot Frank/Getty Images
Title Page Image: © Steve Bloom Images/NASA/Alamy
Cover Printer: Transcontinental Beauceville
Compositor: Pre-Press Company, Inc.
Printer: Transcontinental Beauceville
© 2005, 2007 Thomson Brooks/Cole, a part of The Thomson
Corporation. Thomson, the Star logo, and Brooks/Cole are
trademarks used herein under license.
Library of Congress Control Number: 2006926271
ALL RIGHTS RESERVED. No part of this work covered by the
copyright hereon may be reproduced or used in any form or by any
means—graphic, electronic, or mechanical, including photocopying,
recording, taping, web distribution, information storage and retrieval
systems, or in any other manner—without the written permission of
the publisher.
Printed in Canada
1 2 3 4 5 6
7
10
09
08
07
06
For more information about our products, contact us at:
Thomson Learning Academic Resource Center
1-800-423-0563
For permission to use material from this text or product, submit
a request online at http://www.thomsonrights.com.
Any additional questions about permissions can be submitted by
e-mail to [email protected].
iv
ISBN 0-495-11287-9
ExamView® and ExamView Pro® are registered trademarks of
FSCreations, Inc. Windows is a registered trademark of the Microsoft
Corporation used herein under license. Macintosh and Power Macintosh are registered trademarks of Apple Computer, Inc. Used herein
under license.
© 2007 Thomson Learning, Inc. All Rights Reserved. Thomson
Learning WebTutor™ is a trademark of Thomson Learning, Inc.
Thomson Higher Education
10 Davis Drive
Belmont, CA 94002-3098
USA
About the Authors
Gray Thompson is
Jon Turk is a chemist,
Professor of Geology at
professional geoscience
The University of
writer, and adventurer. He
Montana, where he teaches
received his Ph.D in 1971,
Introductory Geology,
and later that year Jon
Mineralogy, Summer Field
co-authored the first envi-
Mapping, and graduate
ronmental science college
courses in Clay Mineralogy and Shale Petrology. He has
textbook in the country. In the 32 years since then, Jon
published more than 20 research papers in international
has continued his career as a science writer by publish-
journals, mostly co-authored with his students. He is also
ing 23 environmental and geoscience texts. Jon’s love of
a mountaineer and professional guide with first ascents,
unspoiled environments and his fascination for the wild
many with Jon Turk, of peaks and routes in the Rocky
places on this planet have also led to a distinguished ca-
Mountains, Alaska, the Yukon, Baffin Island, the Alps,
reer as an adventurer. He has kayaked around Cape
the Karakoram, and the Himalayas. He has authored
Horn as well as the 3,000 miles between Japan and
many articles published in international climbing maga-
Alaska, crossed the western Gobi of Mongolia, unsup-
zines and journals, and has been the subject of other arti-
ported, on a mountain bike, and was the first to ascend
cles in these publications. Many of the photographs in
Lamo-she Peak (6,070 meters) in the eastern Himalayas
this text were taken by Thompson and Turk on their
with co-author Gray Thompson. He has written nu-
climbing trips and expeditions over the past fifteen years.
merous magazine articles about his expeditions as well
as adventure/travel books, including In the Wake of the
Jomon: Stone Age Mariners and a Voyage Across the Pacific (McGraw Hill 2005).
v
Contents Overview
1
UNIT
1
EARTH MATERIALS AND TIME 19
2
3
4
5
UNIT
2
3
4
The Active Earth: Plate Tectonics 128
Earthquakes and the Earth’s Structure 154
Volcanoes and Plutons 180
Mountains 208
SURFACE PROCESSES 231
10
11
12
13
14
UNIT
Minerals 20
Rocks 44
Geologic Time: A Story in the Rocks 73
Geologic Resources 96
INTERNAL PROCESSES 127
6
7
8
9
UNIT
Earth Systems 1
Weathering, Soil, and Erosion 232
Fresh Water: Streams, Lakes, Ground Water, and Wetlands 262
Water Resources 295
Glaciers and Ice Ages 326
Deserts and Wind 353
THE OCEANS 373
15 Ocean Basins 374
16 Oceans and Coastlines 398
UNIT
5
THE ATMOSPHERE 429
17
18
19
20
21
UNIT
6
The Atmosphere 430
Energy Balance in the Atmosphere 451
Moisture, Clouds, and Weather 470
Climate 507
Climate Change 528
ASTRONOMY 557
22 Motions in the Heavens 558
23 Planets and Their Moons 581
24 Stars, Space, and Galaxies 607
Glossary G.1
Appendix A.1
Index I.1
vi
Contents
1 Earth Systems 1
1.1
1.2
1.3
1.4
1.5
1.6
Flowers Bloom on Earth,Venus Boils, and Mars Freezes 2
The Earth’s Four Spheres 4
Earth Systems 8
Time and Rates of Change in Earth Science 9
Threshold and Feedback Effects 12
Humans and Earth Systems 13
FOCUS ON: Hypothesis,Theory, and Law 15
UNIT 1
EARTH MATERIALS AND TIME 19
2 Minerals 20
2.1
2.2
2.3
2.4
2.5
2.6
2.7
What Is a Mineral? 23
The Chemical Composition of Minerals 24
Crystals: The Crystalline Nature of Minerals 25
Physical Properties of Minerals 28
Mineral Classes and the Rock-Forming Minerals 31
Commercially Important Minerals 33
Harmful and Dangerous Rocks and Minerals 36
FOCUS ON: Elements, Atoms, and Chemical Bonds 26
3 Rocks 44
3.1
3.2
3.3
3.4
Rocks and the Rock Cycle 45
Igneous Rocks 47
Sedimentary Rocks 51
Metamorphic Rocks 61
FOCUS ON: Cooling and Crystallization
of Magma: Bowen’s Expertment 52
4 Geologic Time: A Story in the
Rocks 73
4.1
4.2
4.3
Earth Rocks, Earth History, and Mass Extinctions 74
Geologic Time 77
Relative Geologic Time 79
vii
4.4
4.5
4.6
Unconformities and Correlation 81
Absolute Geologic Time 84
The Geologic Column and Time Scale 89
FOCUS ON: Carbon-14 Dating 88
5 Geologic Resources 96
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
Mineral Resources 97
Ore and Ore Deposits 97
Mineral Reserves 105
Mines and Mining 105
Energy Resources: Coal, Petroleum, and Natural Gas 106
Energy Resources: Tar Sands and Oil Shale 111
Energy Resources: Renewable Energy 112
Energy Resources: Nuclear Fuels and Reactors 115
Conservation as an Alternitive Energy Resource 117
Energy for the Twenty-First Century 119
FOCUS ON: The 1872 Mining Law 103
UNIT 2
INTERNAL PROCESSES 127
6 The Active Earth: Plate Tectonics 128
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
viii
Alfred Wegener and the Origin of an Idea: The Continental Drift
Hypothesis 129
The Earth’s Layers 131
The Sea-Floor Spreading Hypothesis 135
The Theory of Plate Tectonics 137
The Anatomy of a Tectonic Plate 143
Why Plates Move: The Earth As a Heat Engine 143
Supercontinents 145
Isostasy: Vertical Movement of the Lithosphere 145
How Plate Movements Affect Earth Systems 145
7
Earthquakes and the Earth’s
Structure 154
7.1
7.2
7.3
7.4
7.5
Anatomy of an Earthquake 155
Earthquake Waves 157
Earthquakes and Tectonic Plate Boundaries 161
Earthquake Prediction 166
Earthquake Damage and Hazard Mitigation 167
7.6
7.7
Studying the Earth’s Interior 172
The Earth’s Magnetism 174
8 Volcanoes and Plutons 180
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
Magma 181
Basalt and Granite 184
Partial Melting and the Origin of Continents 186
Magma Behavior 187
Plutons 189
Volcanoes 192
Volcanic Explosions: Ash-Flow Tuffs and Calderas 196
Risk Assessment: Predicting Volcanic Eruptions 200
Volcanic Eruptions and Global Climate 202
9 Mountains 208
9.1
9.2
9.3
9.4
9.5
9.6
UNIT 3
Folds and Faults: Geologic Structures 209
Mountains and Mountain Ranges 216
Island Arcs 217
The Andes: Subduction at a Continental Margin 218
The Himalayas: A Collision between Continents 221
Mountains and Earth Systems 225
SURFACE PROCESSES 231
10 Weathering, Soil, and Erosion 232
10.1
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
Weathering and Erosion 233
Mechanical Weathering 234
Chemical Weathering 236
Soil 239
Erosion 247
Landslides 247
Types of Landslides 251
Three Historic Landslides 255
Predicting and Avoiding Landslides 257
FOCUS ON: Representative Reactions in
Chemical Weathering 238
FOCUS ON: Soil Erosion and Agriculture 242
FOCUS ON: The Hubbard Brook Experimental Forest 248
ix
11 Fresh Water: Streams, Lakes,
Ground Water, and Wetlands 262
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
The Water Cycle 263
Streams 264
Stream Erosion and Mountains: How Landscapes Evolve 269
Stream Deposition 271
Floods 272
Lakes 276
Ground Water 278
Hot Springs, Geysers, and Geothermal Energy 285
Wetlands 287
12 Water Resources 295
12.1
12.2
12.3
12.4
12.5
12.6
12.7
12.8
12.9
12.10
Water Supply and Demand 296
Dams and Diversion 298
The Great American Desert 307
Water and International Politics 311
Water Pollution 311
How Sewage, Detergents, and Fertilizers Pollute Waterways 313
Toxic Pollutants, Risk Assessment, and Cost–Benefit Analysis 314
Ground Water Pollution 315
Nuclear Waste Disposal—Yucca Mountain 318
The Clean Water Act—A Modern Perspective 320
13 Glaciers and Ice Ages 326
13.1
13.2
13.3
13.4
13.5
13.6
13.7
Formation of Glaciers 327
Glacial Movement 328
Glacial Erosion 332
Glacial Deposits 336
The Pleistocene Ice Age 341
Snowball Earth: The Greatest Ice Age in Earth History 345
The Earth’s Disappearing Glaciers 347
14 Deserts and Wind 353
14.1
14.2
14.3
x
Why Do Deserts Exist? 354
Water and Deserts 357
Two American Deserts 361
14.4
14.5
UNIT 4
Wind 362
Desertification 368
THE OCEANS 373
15 Ocean Basins 374
15.1
15.2
15.3
15.4
15.5
15.6
The Origin of Oceans 375
The Earth’s Oceans 377
Studying the Sea Floor 378
Features of the Sea Floor 379
Sediment and Rocks of the Sea Floor 388
Continental Margins 390
16 Oceans and Coastlines 398
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
16.10
16.11
UNIT 5
Geography of the Oceans 400
Sea Water 400
Tides 402
Sea Waves 404
Storm Surge 405
Ocean Currents 405
The Sea Coast 410
Emergent and Submergent Coastlines 412
Beaches 416
Life in the Sea 420
Global Warming and Sea-Level Rise 423
THE ATMOSPHERE 429
17 The Atmosphere: Evolution and
Composition 430
17.1
17.2
17.3
17.4
17.5
17.6
17.7
Earth’s Early Atmospheres 432
Life, Iron, and the Evolution of the Modern Atmosphere 433
The Modern Atmosphere 437
Atmospheric Pressure 437
Atmospheric Temperature 438
Air Pollution 439
Depletion of the Ozone Layer 445
xi
18 Energy Balance in the
Atmosphere 451
18.1
18.2
18.3
18.4
18.5
Incoming Solar Radiation 452
The Radiation Balance 455
Energy Storage and Transfer—The Driving Mechanisms for Weather
and Climate 456
Temperature Changes with Latitude and Season 459
Temperature Changes with Geography 463
FOCUS ON: Latitude and Longitude 459
19 Moisture, Clouds, and Weather 470
19.1
19.2
19.3
19.4
19.5
19.6
19.7
19.8
19.9
19.10
19.11
19.12
Moisture in Air 471
Cooling and Condensation 472
Rising Air and Precipitation 474
Types of Clouds 477
Fog 480
Pressure and Wind 481
Fronts and Frontal Weather 484
How Earth’s Surface Features Affect Weather 490
Thunderstorms 491
Tornadoes and Tropical Cyclones 493
Hurricane Katrina 496
El Niño 499
FOCUS ON: Inversion Layers and Air Pollution 476
20 Climate 507
20.1
20.2
20.3
20.4
20.5
Major Factors That Control Earth’s Climate 508
Global Winds and Climate 510
Ocean Currents and Climate 513
Climate Zones of the Earth 513
Urban Climates 523
21 Climate Change 528
21.1
21.2
21.3
21.4
21.5
21.6
Climate Change in Earth’s History 530
Measuring Climate Change 533
Astronomical Causes of Climate Change 535
Water and Climate 536
The Natural Carbon Cycle and Climate 537
Tectonics and Climate Change 539
21.7
21.8
21.9
UNIT 6
Greenhouse Effect: The Carbon Cycle and Global Warming 541
Feedback and Threshold Mechanisms in Climate Change 547
The Kyoto Treaty on Greenhouse Warming 550
ASTRONOMY 557
22 Motions in the Heavens 558
22.1
22.2
22.3
22.4
22.5
The Motions of the Heavenly Bodies 559
Aristotle and the Earth-Centered Universe 559
The Renaissance and the Heliocentric Solar System 564
The Motions of the Earth and the Moon 567
Modern Astronomy 573
FOCUS ON: The Constellations 560
23 Planets and Their Moons 581
23.1
23.2
23.3
23.4
23.5
23.6
23.7
23.8
The Solar System: A Brief Overview 582
The Terrestrial Planets 582
The Moon: Our Nearest Neighbor 590
The Jovian Planets: Size, Compositions, and Atmospheres 593
Moons of the Jovian Planets 597
Planetary Rings 600
Pluto and Beyond 601
Asteroids, Comets, and Meteoroids 601
FOCUS ON: Extraterrestrial Life 592
24 Stars, Space, and Galaxies 607
24.1
24.2
24.3
24.4
24.5
24.6
24.7
24.8
24.9
24.10
24.11
24.12
24.13
In the Beginning: The Big Bang 608
The Nonhomogeneous Universe 610
The Birth of a Star 610
The Sun 614
Stars: The Main Sequence 617
The Life and Death of a Star 619
Neutron Stars, Pulsars, and Black Holes 622
Galaxies 625
Milky Way 627
Quasars 629
Dark Matter 630
The End of the Universe 630
Why Are We So Lucky? 632
FOCUS ON: Measuring Distances in Space 617
APPENDIX
A
Identifying Common Minerals A.1
B
Systems of Measurement A.10
C
Periodic Table of the Elements A.13
International Table of
Atomic Weights A.14
D
Rock Symbols A.15
E
Star Maps A.16
Glossary G.1
Index I.1
xiv
Preface
In 1979 James Lovelock published his landmark book,
Gaia: A New Look at Life on Earth (Oxford University
Press), which proposed that plants and animals contribute
to the evolution of Earth’s atmosphere. Furthermore,
Lovelock proposed that Earth could be likened to a living
organism, whose environment is regulated by homeostatic interactions between earth, air, water, and life. While
the Gaia hypothesis was initially accepted by many in the
environmental community, it was criticized and debated
within the scientific community. Although the debate
continues, scientists have accumulated a huge amount of
data over the past 27 years to show that earth, air, water,
and living organisms interact in complex ways and that
these interactions profoundly affect Earth’s environment.
The authors of this book, Gray Thompson and Jon
Turk, have been involved in environmental and earth science research and education for nearly four decades. We
have carefully watched the unfolding of the Gaia debate
and read volumes of literature describing the mechanisms of current and paleo planetary change. In this
fourth edition of Earth Science and the Environment, we
stress the interrelationship among Earth’s four systems
in greater detail than in any of our previous textbooks.
In March 2000, a Connecticut-sized iceberg broke
off the Ross Ice Shelf in Antarctica and floated northward to melt in warmer waters. We ask, Why did the ice
break free? Was it a consequence of normal glacial movement and changing seasons, or was it caused by global
climate change? Will the breakup of the Ross Ice Shelf
affect distant coastlines and ecosystems?
Every year, volcanic eruptions blast fiery lava, dark
ash, and billowing steam into the sky. Sometimes nearby
houses are buried and unlucky residents are killed.
Beyond the immediate tragedy, we again ask questions
about cause and consequence: What Earth processes produced the eruption? Will the dark cloud of suspended ash
shadow the sun and alter regional or global climate?
In attempting to answer these and similar questions,
we learn that Earth’s systems are interrelated. For example, deep forces within Earth generate volcanic eruptions. But an eruption also emits the greenhouse gas
carbon dioxide that contributes to global warming and
that, in turn, may accelerate the breakup of Antarctic ice.
Following the chain of events one step further, extensive
ice shelf collapse causes sea level rise, which alters global
climate even more.
Turning our focus from the present into deep geologic time, abundant evidence reveals that just about
anywhere on our planet, the rock, the landscape, the climate, and the living organisms have changed throughout
Earth’s history. Fossil ferns and dinosaur bones in Connecticut tell us that this temperate region was once warm
and tropical. Millions of years after the dinosaurs became extinct, continental glaciers bulldozed across the
landscape leaving huge mounds of rock and sediment.
Earth science is a study of the world around us: the
rocks beneath our feet, the air we breathe, the water that
exists almost everywhere in our environment, and all the
living organisms that share our planet with us. Earth science also extends a view into space to look at distant
planets, stars, and faraway galaxies.
Earth scientists study the mechanisms of change.
How did the climate in Connecticut fluctuate from
warm and humid to frigidly cold? What forces drive volcanic eruptions, and why do they concentrate in some
regions but not in others? As scientists sought to answer
these and other related questions, they have found that
Earth is a complex system composed of smaller, interconnected and interacting systems. Whenever we discuss
a process or event, we simultaneously examine the disparate systems that affect or are affected by that geological, atmospheric, biological, or oceanic change.
Earth science encompasses the entire history of our
planet, from its formation 4.6 billion years ago to the
present. We go back in time and ask how Earth evolved,
how and when water collected to form oceans, how continents rose out of the watery wilderness, and what
processes created an atmosphere favorable to life.
Over the past hundred years, technology has given
the human species unprecedented power to alter Earth.
As a consequence, we are engaged in a great and uncontrolled experiment to observe how our planetary systems will react to these perturbations. It is an experiment
unique in scale and process. In a traditional laboratory
study, scientists examine two parallel systems. One is
perturbed, the other (the control) is not perturbed, and
scientists observe the different behaviors of the two. But
we have only one Earth. If we increase the carbon dioxide concentration of the air, our planetary systems will
change and we will never know what would have happened if the atmospheric carbon dioxide concentration
had remained constant.
PREFACE
xv
Courtesy of Graham R. Thompson/Jonathan Turk
In addition to the fact that we can’t perform controlled experiments on Earth, we can’t easily retreat
from our mistakes. Once change has occurred, no one
can say, “Woops, that didn’t work; let’s back up, start at
the beginning, and try something different.” Therefore it
is vitally important that we proceed carefully as we alter
the environment that sustains us. No textbook can offer
answers or solutions to the complex issues that we face,
but the fourth edition of Earth Science and the Environment provides background information needed to understand basic Earth processes and to formulate critical
decisions that will define our future.
Many of Earth’s systems interactions discussed in the
text summarize the results of research published since
the last edition was written. Thus, at the same time that
we are presenting the most accurate modern picture of
planetary change, we also teach that science is a living
process and not a set of stale facts to be memorized. We
emphasize that scientists propose models, frequently
disagree with one another, and then return to the laboratory, the computer screen, or the field to gain more
information and to try to answer difficult questions.
Sequence of Topics
Because different earth science courses can have many different emphases, information presented in these courses
can follow a wide variety of logical sequences. In this
book, we have chosen to introduce Earth’s materials and
geological time, and then to start from Earth’s interior and
work outward. Thus the book is divided into six units:
Unit 1: Earth Materials and Time
Unit 2: Internal Processes
Unit 3: Surface Processes
Unit 4: The Oceans
Unit 5: The Atmosphere
Unit 6: Astronomy
Some instructors may prefer other sequences for
covering these topics. The structure of this book allows
many alternative sequences.
Special Features
In previous editions of Earth Science, we isolated many
topics and Case Histories into Focus On boxes that
were set aside and highlighted in color. The rationale was
that some topics are not necessary to the sequential development of each chapter but may be of interest to certain classes. In this edition, we felt that most of these
topics are so integral to the discussions that they should
be incorporated with the text and not set aside. Thus, we
maintain a few Focus On boxes to highlight some examples, but, in most cases, we have fused the main text information with the examples.
Art and Photographs
Earth science is a visual discipline. Landscapes tell their
own stories, and many processes can be illustrated with
line drawings. The authors took many of the pho-
xvi
PREFACE
tographs in this book during their extensive travels and
field research. We have upgraded much of the line art
and rendered many new pieces. We have also continued
to emphasize important topics with large-format concept art called “Systems Perspective” to capture the students’ attention and curiosity.
Chapter Review Material
A short summary of important chapter material is provided at the end of each chapter. Following the summary, we have included and expanded our unique art
called “Earth Systems Interactions.” These schematic
drawings show the four spheres of earth science:
geosphere, hydrosphere, atmosphere, and biosphere.
Arrows connect the four spheres with labels showing
how the separate systems interact. This art emphasizes
the interactivity of Earth’s systems and at the same time
provides a graphical review of many of the discussions
in the chapter.
Questions
We provide two types of end-of-chapter questions. The
students can answer the review questions in a straightforward manner from the material in the text. Thus,
these questions allow students to test themselves on how
completely they have learned the material in the chapter.
At the same time, discussion questions challenge students to apply what they have learned to an analysis of
situations not directly described in the text. These questions often have no absolute correct answers. In addition, throughout the text the captions of selected figures
contain questions designed to provoke thought and discussion about important issues raised by those figures.
Glossary and Appendix
A glossary is provided at the end of the book. Appendices cover mineral classification and identification, the
International System of Units (SI) , the elements, rock
symbols, and star maps.
ANCILLARIES
This edition is accompanied by an extensive suite of
both print and media supplements.
ThomsonNOW, the first assessment-driven and
student-centered tutorial created for the earth science
market, focuses student study time on concept mastery
and is FREE to students with each purchase of a new
textbook. This Web-based student tutorial is completely flexible and can be used in any order, but it features a default three-step mastery process designed to
maximize the effectiveness of the system. The first step,
called “What Do I Know?” consists of a diagnostic
“Pre-Test” to help students identify their specific
weaknesses in any particular chapter. The results provide a “Personalized Learning Plan,” based on each
student’s results.
The second step, “What Do I Need to Learn?” provides activities drawn from the wealth of book-specific,
interactive resources like animations, movies, and tutorials that students can work with.
The third step, “What Have I Learned?” is an
optional “Post-Test” to ensure that the student has
mastered the concept(s) in each chapter. As with the
Pre-Test, student results may be e-mailed to the instructor—helping both the instructor and the student
assess progress. By providing students with a better understanding of exactly what they need to focus on,
ThomsonNOW helps students maximize their study
time, bringing them a step closer to success! ThomsonNOW is available at www.thomsonedu.com.
GIS Investigations
Do you want to integrate GIS into your earth science
course? These groundbreaking guides, by Hall-Wallace
et al., let even novice users tap the power of GIS to explore, manipulate, and analyze large data sets. The ArcView [r]-based guides come with all the software and
data sets needed to complete the exercises.
New to This Edition
ArcGIS[r] versions of these manuals are available with
online, downloadable data sets and an online “Instructor’s Manual.” These are available alone, bundled
together, and/or bundled with Earth Science and the
Environment.
Exploring Tropical Cyclones: GIS Investigations for
the Earth Sciences
ISBN: 0-534-39147-8
ISBN: 0-495-11543-6 - ArcGIS version
Exploring Water Resources: GIS Investigations for
the Earth Sciences
ISBN: 0-534-39156-7
ISBN: 0-495-11512-6 - ArcGIS version
Exploring the Dynamic Earth: GIS Investigations for
the Earth Sciences
ISBN: 0-534-39138-9
ISBN: 0-495-11509-6 - ArcGIS version
Exploring the Ocean Environment: GIS Investigations for the Earth Sciences
ISBN: 0-534-423507
ISBN: 0-495-11506-1 - ArcGIS version
Online Instructor’s Manual/Test Bank
This manual, written by the main text authors, contains
discussion sections (highlighting the most important/
interesting topics and suggesting alternative teaching sequences where appropriate), answers to discussion questions from the main text, selected readings, and a test
bank consisting of multiple-choice, true/false, and fillin-the-blank questions and answers.
Transparency Acetates
0495-113921
This set of 100 transparency acetates contains photos
and images taken directly from the text.
Slides
0030214793
This set of slides contains full-color photos and images
taken directly from the text.
ExamView computerized testing
Create, deliver, and customize tests and study guides
(both print and online) in minutes with this easy-to-use
assessment and tutorial system. ExamView offers both
a Quick Test Wizard and an Online Test Wizard that
guide you step-by-step through the process of creating
tests, while the unique “WYSIWYG” capability allows
you to see the test you are creating on the screen exactly
as it will print or display online. You can build tests of
up to 250 questions using up to 12 question types. Using
ExamView’s complete word processing capabilities, you
can enter an unlimited number of new questions or edit
existing questions.
Multimedia Manager
ISBN: 0-534-49314-9 (CD format)
This easy-to-use multimedia lecture tool allows you to
quickly assemble art and database files with notes to create fluid lectures. Available on CD, the Multimedia
PREFACE
xvii
Courtesy of Graham R. Thompson/Jonathan Turk
Manager includes a database of animations and images
from earth science titles published by Brooks, Cole. The
simple interface makes it easy for you to incorporate
graphics, digital video, animations, and audio clips into
your lectures.
Book Companion Website
www.thomsonedu.com/earthscience/thompson
ACKNOWLEDGEMENTS
The first two editions of Earth Science and the Environment were published under the guidance of our close personal friend, senior editor John Vondeling at Saunders
College Publishing. Tragically, John developed cancer and
passed away. Earth Science and the Environment drifted
in limbo for several months until it was taken under the
wing of Brooks, Cole Publishing and a new editorial
team, headed by acquisitions editor Keith Dodson. It has
been a delight to work with Keith and the professionals at
Brooks, Cole. They have brought new vitality to the manuscript preparation and to the exciting ancillary material
that accompanies the text. The team at Thomson Arts and
Sciences Publishing has changed over the years, but enthusiasm for the book has remained strong. Special thanks
to Peter Adams, our new acquisitions editor, and the following members of the fourth edition project team: Anna
Jarzab—editorial assistant, Carol Benedict—assistant editor, Sam Subity—technology project manager, Kelley
McAllister—marketing manager, Nathaniel BergsonMichelson—executive advertising project manager,
Belinda Krohmer—content project manager, and Vernon
Boes—art director. They have all helped us through the
complex process of moving from a rough manuscript to a
final book.
We would also like to extend special thanks to numerous independent contractors who worked on the book.
Wendy Pizzi at Pre-Press Company has tirelessly overseen the day-to-day details of production. Nina Maclean,
xviii
PREFACE
our personal editorial assistant, keeps confusion at bay in
the home office. Terri Wright did the photo research and
book design, and Lisa Torri styled the art for the Earth
Systems Interactions figures, which have been given their
due prominence in this edition.
In addition to the editorial and production teams, all
four editions of the manuscript have been extensively reviewed at several stages, and the numerous careful criticisms of the art and text have helped shape the book and
ensure accuracy.
Reviewers of the fourth edition:
Patricia Crews, Florida Community College of
Jacksonville
Lois Breur Krause, Clemson University
Veronique L. Lankar, Pace University/Mount St.
Mary’s College
Leland Timothy Long, Georgia Institute of Technology
Sadredin C. Moosavi, Minnesota State University–
Mankato
Reviewers of third edition:
Jens Bischof, Old Dominion University
Roland H. Brady, California State University at
Fresno
Nathalie Brandes, University of Wisconsin, Eau
Claire
Stan Celestian, Glendale Community College
Marvin Cochrane, Troy State University
Scott T. Dreher, Indiana State University
Jim Durbin, University of Southern Indiana
Joseph Graf, Southern Oregon University
Chris Hansen, Southern Adventist University
Christopher Hooker, Waubonsee Community College, Sugar Grove
R. V. Krishnamurthy, Western Michigan University
Steven J. Maier, Northwestern Oklahoma State
University
W. Patrick Seward, Rogers State University
Steve Taylor, Western Oregon University
Reviewers of second edition:
James Albanese, State University of New York at
Oneonta
Sandra Brake, Indiana State University
Mark Evans, University of Pittsburgh
Bryan Gregor, Wright State University
Clay Harris, Middle Tennessee State University
Steve LaDochy, California State University–Los
Angeles
John Madsen, University of Delaware
Joseph Moran, University of Wisconsin–Green Bay
Paul Nelson, St. Louis Community College at
Meramec
Adele Schepige, Western Oregon State College
Richard Smosna, West Virginia University
Ronald Wasowski, King’s College
Reviewers of first edition:
James Albanese, State University of New York at
Oneonta
John Alberghini, Manchester Community College
Calvin Alexander, University of Minnesota
Edmund Benson, Wayne County Community
College
Robert Brenner, University of Iowa
Walter Burke, Wheelock College
Wayne Canis, University of Northern Alabama
Stan Celestian, Glendale Community College
Edward Cook, Tunxis Community College
James D’Amario, Hartford Community College
Joanne Danielson, Shasta College
John Ernissee, Clarion University
Richard Faflak, Valley City State University
Joseph Gould, St. Petersburg Junior College
Bryan Gregor, Wright State University
Miriam Hill, Indiana University–Southeast
John Howe, Bowling Green State University
DelRoy Johnson, Northwestern University
Alan Kafka, Boston College
William Kohland, Middle Tennessee State University
Thomas Leavy, Clarion University
Doug Levin, Bryant College
Jim LoPresto, Edinboro University of Pennsylvania
Glenn Mason, Indiana University–Southeast
Joseph Moran, University of Wisconsin–Green Bay
Alan Morris, University of Texas–San Antonio
Jay Pasachoff, Williams College
Frank Revetta, Potsdam College
Laura Sanders, Northeastern Illinois University
Barun K. Sen Gupta, Louisiana State University
James Shea, University of Wisconsin–Parkside
Kenneth Sheppard, East Texas State University
Doug Sherman, College of Lake County
All of these people and many of their associates have worked hard and efficiently to produce the finished product.
Graham R. Thompson,
Missoula, Montana
Jonathan Turk,
Darby, Montana
PREFACE
xix
This page intentionally left blank
CHAPTER
Earth
Systems
© John M. Roberts/CORBIS
1
1.1
1.2
1.3
1.4
1.5
1.6
Although scientists
have searched for
living organisms on
other planets, so far
we have found life
only on Earth. From
alpine meadows,
such as this
landscape in Mount
Rainier National
Park, to deserts, to
the deep sea floor,
life has adapted to
almost all
conceivable Earthy
environments.
Flowers Bloom on Earth, Venus Boils, and Mars Freezes
The Earth’s Four Spheres
Earth Systems
Time and Rates of Change in Earth Science
Threshold and Feedback Effects
Humans and Earth Systems
1
Throughout this
chapter, the
ThomsonNOW logo indicates an opportunity
for online self-study, which:
• Assesses your understanding of important
concepts and provides a personalized
study plan
• Links you to animations and simulations
to help you study
• Helps to test your knowledge of
material and prepare for exams
Visit ThomsonNOW at
www.thomsonedu.com/1ogin to access
these resources.
E
arth is sometimes called the water planet or blue planet because azure seas
cover more than two-thirds of its surface. Earth is the only planet or moon in
the Solar System with rain falling from clouds, and water that runs over the
land to collect in extensive oceans. It is also the only body that we know of
that supports life. ■
1.1
Flowers Bloom on Earth,
Venus Boils, and Mars
Freezes
Our Solar System originally evolved from a cloud of
dust particles and gas rotating in the vast emptiness of
space. Under the relentless pull of gravity, these particles condensed into discrete bodies that gradually
formed the Sun, the planets, and their moons. Thus, all
of the planets formed from the same original mixture of
materials. Yet today, the planets are distinctly different
from one another. To appreciate these differences, let us
briefly compare Earth with its two closest neighbors,
Venus and Mars.
Of all the planets, Venus most closely resembles
Earth in size, density, and distance from the Sun. Consequently, astronomers once thought that Venus might
be similar to Earth, and that both water and life might
be found there. However, data obtained from spacecraft
reveal that Venus is extremely inhospitable ( Figure
1.1). Any Earth-like life would quickly suffocate in the
carbon dioxide–rich Venusian atmosphere. Caustic sulfuric acid clouds fill the sky there. In addition, the surface of Venus is hot enough to melt lead, and therefore
hot enough to destroy the organic molecules necessary
for life.
As for Mars, early in its history it must have had a
temperate climate somewhat like that of Earth today.
Images from spacecraft and remote rovers show extinct
stream canyons, sea floors, and lake beds, indicating that
flowing water must have been abundant on the planet
( Figure 1.2). But today, the Martian surface is frigid
and dry. Mars’s winter ice caps are mostly frozen carbon
dioxide, commonly called dry ice. If water is present on
2
CHAPTER 1
• Earth Systems
Mars, it lies frozen beneath the planet’s surface; Mars
also has almost no atmosphere.
If Earth, Venus, and Mars formed from the same materials, why are the three planets so different today? Why
are we the only planet favored with great oceans, cascading waterfalls, blue skies, and abundant life? Shortly after
the formation of the planets, the original atmospheres of
Earth, Venus, and Mars evolved into swirling mixtures of
carbon dioxide, carbon monoxide, water, ammonia,
methane, and other gases. To appreciate what happened
next, we need to understand the behavior of carbon dioxide and water in planetary environments.
Water can be a solid, liquid, or gas. If liquid water
cools, it turns to ice; when it is heated, it evaporates to
form vapor. Thus water leaves the atmosphere when it
condenses or freezes, whereas it enters the atmosphere
when it vaporizes. Carbon dioxide also exists in a variety
of forms. At Earth’s surface, carbon dioxide occurs as an
atmospheric gas, dissolves in seawater, and combines with
calcium and oxygen to form a type of rock called limestone. (Carbon dioxide also exists as a liquid and a solid,
but not in Earth’s surface environment.) Carbon dioxide
gas and water vapor are both greenhouse gases—they absorb infrared radiation and warm the atmosphere.
Because Venus is closer to the Sun than Earth is, it receives more solar radiation and was originally a bit
warmer than Earth is now. Due to the higher temperature
on Venus, water vapor either never condensed, or if it did,
it quickly evaporated again. Because there were no seas
for carbon dioxide to dissolve into, most of the carbon
dioxide also remained in the atmosphere. Both of these
greenhouse gases further heated up Venus’s atmosphere.
Heat released more water and carbon dioxide into the
atmosphere and, subsequently, these gases trapped more
heat. The temperature spiraled higher and higher.
In contrast, Earth, being farther from the Sun, was
cool enough so that the water vapor condensed to form
vast oceans. Large amounts of carbon dioxide then dis-
JPL/ USGS; inset, NASA
FIGURE 1.1 Space shot of Venus. Before astronomers could peer through the Venusian cloud cover or measure its
temperature and composition, they speculated that Venus may harbor life.Today we know that the atmosphere is so hot and
corrosive that living organisms could not possibly exist.
in this favorable environment. But because Mars is further
from the Sun than Earth is, its atmosphere cooled more
than Earth’s. This small initial cooling caused more water
vapor to condense and more carbon dioxide to dissolve
into the seas, lowering the amounts of greenhouse gases in
the Martian atmosphere. The temperature spiraled downward. Today, the Martian surface occasionally becomes as
warm as an autumn afternoon on Earth (20°C), but more
commonly, the temperature is below freezing. Temperatures as low as –140°C have been recorded. At this
extreme, carbon dioxide freezes into dry ice.
In summary, Venus is closer to the Sun and receives
more solar radiation than either Earth or Mars. This
NASA /JPL
solved in the seas or reacted to form limestone. Thus,
large quantities of these two greenhouse gases were removed from the atmosphere. Fortunately for us, the temperature stabilized in a range favorable for the existence of
liquid water and for the emergence and evolution of life.
Mars is a little farther from the Sun than Earth is, and
consequently it receives a little less solar energy. A Martian atmosphere rich in carbon dioxide and water vapor
probably evolved between 4.0 and 3.5 billion years ago.
Both of these greenhouse gases absorbed the Sun’s heat,
producing a temperate climate despite the planet’s greater
distance from the Sun. Rain fell from clouds, rivers
flowed, wind blew over shallow seas. Perhaps life evolved
FIGURE 1.2 Water once flowed over the surface of Mars, eroding canyons and depositing sediment. However,
today the planet is frigid and dry.
1.1 Flowers Bloom on Earth,Venus Boils, and Mars Freezes
3