EARTH SCIENCES - Notable Research and Discoveries Part 1 ppt

EARTH SCIENCES: Notable Research and DiscoveriesCopyright © 2010 by Kyle Kirkland, Ph.D.. An imprint of Infobase Publishing You can fi nd Facts On File on the World Wide Web at http://ww

EARTH SCIENCES

KYLE KIRKLAND, PH.D.

EARTH SCIENCES

EARTH SCIENCES: Notable Research and Discoveries

Copyright © 2010 by Kyle Kirkland, Ph.D.

All rights reserved No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any infor- mation storage or retrieval systems, without permission in writing from the publisher For information contact:

Facts On File, Inc.

An imprint of Infobase Publishing

You can fi nd Facts On File on the World Wide Web at http://www.factsonfi le.com Excerpts included herewith have been reprinted by permission of the copyright holders; the author has made every eff ort to contact copyright holders Th e publishers will be glad

to rectify, in future editions, any errors or omissions brought to their notice.

Text design by Kerry Casey

Illustrations by Sholto Ainslie and Dale Williams

Photo research by Tobi Zausner, Ph.D.

Composition by Mary Susan Ryan-Flynn

Cover printed by Bang Printing, Inc., Brainerd, Minn.

Book printed and bound by Bang Printing, Inc., Brainerd, Minn.

Date printed: March 2010

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

Preface ix Acknowledgments xiii Introduction xv

Introduction 2Seismic Waves 5

United States Geological Survey (USGS) 10

Inside the Planet 10Drilling into Earth 15Heat of Earth’s Interior 17

Project Mohole—An Ambitious Attempt

to Reach Earth’s Mantle 18

Tectonic Plate Movement 21Dynamics and Interactions of Earth’s Interior 23Charting the Depths with Research

Geological Survey of Canada 40

Magnetosphere 43

Northern and Southern Lights 44

Dynamo Theory of Earth’s Magnetic Field 47Magnetic Fields of Other Bodies

in the Solar System 50Variations in Earth’s Magnetic Field 52

Turning Geothermal Energy into Electricity 104

Energy and Economics 107Geothermal Drilling 109Geothermal Heat Pumps 112Geothermal Potential and Capacity 114

Interdisciplinary Science—Many Specialties, One Goal 116

Enhanced Geothermal Systems 119Conclusion 122Chronology 123Further Resources 125

Introduction 130The Water Cycle 133

Aquifers—Underground Water Sources 136

Preceding an Earthquake 173Signs of an Impending Earthquake 175Earthquake Forecasts and Probabilities 177Predictions and Consequences 178Strain Accumulation and Surface Deformation 181

San Andreas Fault Observatory at Depth (SAFOD) 182

Conclusion 184

Chronology 186Further Resources 188

Glossary 196 Further Resources 200 Index 205

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earth ScienceS



computer scienceEarth sciencemarine sciencephysicsspace and astronomyweather and climateThe set focuses on the methods and imagination of people who are

certain tasks At the same time, however, these experiments have raised

other questions that future research must answer

The logic and precision of science are elegant, but applying scientific skills can be daunting at first The goals of the Frontiers of Science set are

earth ScienceS

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xiii

Seekers of knowledge satisfy their curiosity about how the world and its organisms work, but the applications of science are not limited

xv

INTRODUCTION

cumference to be (in modern units) about 24,500 miles (39,500 km), a

figure quite close to the modern value, 24,900 miles (40,161 km)

The Italian navigator Christopher Columbus (1451–1506) believed the world was round and sailed west from Spain in an attempt to reach

Sometimes complexity lies masked behind the simplest phenom-tial instruments, indicating direction as the explorers navigated the

1

Th e German scientist Emil Wiechert (1861–1928) off ered a bolder hy-er density As Stephen G Brush wrote in his 1996 book Nebulous Earth,

“Supposing (in accordance with 19th-century ideas) that the molecules in

a solid are already very close together at low pressures, Wiechert argued

the distance between Earth’s surface and its center is approximate-ly the same as the distance between Washington, D.C., and Paris,

France Although it might not sound very far, digging or drilling

through the ground for more than a small fraction of this distance is

not possible

ever Many essential resources are buried belowground, including met-

Gold mine in Alaska (Natalia Bratslavksy/iStockphoto)

eploring earth’s Depths