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Earthquake Insurance: Betting Against Earthquakes 261 12 Living with Earthquakes in California: A Survivor’s Guide Earthquakes recorded by the Southern California Seismic Network between 1975 and 1998, located by a new technique taking into account varying speeds of earthquake waves through different kinds of rock. Nearly 300,000 earthquakes were located. From a paper in the Journal of Geophysical Research by K.B. Richards-Dinger and Peter Shearer of the University of California, San Diego. Thin curved lines are active faults. Note that some active faults are highlighted by earthquakes, but others are not, including much of the San Andreas Fault. Living with Earthquakes in California: A Survivor’s Guide by Robert S. Yeats Oregon State University Press Corvallis Cover: Collapsed building and burned area at Beach and Divisadero in the Marina District, San Francisco, damaged during the Loma Prieta Earthquake of October 17, 1989. Damage was caused by liquefaction and lateral movement of artificial fill that had been emplaced after the 1906 San Francisco Earthquake. Lateral movement caused rupture of underground gas lines, which then caught fire. Photograph by C.E. Meyer, U.S. Geological Survey. The paper in this book meets the guidelines for permanence and durability of the Committee on Production Guidelines for Book Longevity of the Council on Library Resources and the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48-1984. Library of Congress Cataloging-in-Publication Data Yeats, Robert S. California earthquakes : a survivor's guide / Robert S. Yeats. —1st ed. p. cm. Includes bibliographical references and index. ISBN 0-87071-493-7 1. Earthquakes--California. 2. Earthquakes--California--Safety measures. I. Title. QE535.2.U6 Y42 2001 551.22'09794--dc21 00-011859 © 2001 Robert S. Yeats All rights reserved. First edition 2001 Printed in the United States of America Oregon State University Press 101 Waldo Hall Corvallis, OR 97331-6407 541-737-3166 • fax 541-737-3170 http://osu.orst.edu/dept/press Contents Preface vii I. Boosters and Quakers: Three Centuries of People and Earthquakes in California 1 II. Tectonic Plates, Geologic Time, and Earthquakes 26 1. A Concept of Time 27 2. Plate Tectonics 35 3. Earthquake Basics 49 4. The San Andreas Fault System: The Big One 75 5. The Transverse Ranges: LA in the Squeeze 116 6. Shakes in the Back Country: Decades of Violence, Millennia of Silence 133 7. Cascadia 159 8. Memories of the Future: The Uncertain Art of Earthquake Forecasting 185 III. Shaky Ground and Big Waves 217 9. Solid Rock and Bowls of Jello 220 10. Tsunami! 238 IV. Prevention and Countermeasures 260 11. Earthquake Insurance: Betting Against Earthquakes 261 12. Is Your Home Ready for an Earthquake? 279 13. Earthquake Design of Large Structures 297 14. The Federal Government and Earthquakes 312 15. The Role of State and Local Government 329 16. Preparing for the Next Earthquake 348 17. An Uncertain Appointment with a Restless Earth 358 Appendix A. Table of Significant Earthquakes in California 361 Appendix B. Glossary 369 Appendix C. Credits 376 Bibliography 383 Index 393 Preface y professional life changed irrevocably on a February morning in 1971, on an oceanographic expedition off M the Galápagos Islands. As I headed for work in the science lab, I heard reports on the shortwave radio about a massive earthquake in Los Angeles. People had been killed, freeways had collapsed, and a fault scarp had suddenly appeared in the shady neighborhoods of the northern San Fernando Valley. A few months earlier, I had interviewed for a job at California State University at Northridge, and if I had taken it, my family would have been in harm’s way at the same time I was looking at deep-sea cores in the tropics. A few months later, I was hired for the summer by F. Beach Leighton, a professor of geology at Whittier College who had started a consulting business in engineering geology in the Los Angeles area. One of my jobs was mapping the area around the Olive View County Medical Center, which had been destroyed by the earthquake only a few months after it had been completed. I saw first hand the power of Nature: a toppled stairwell, a crumpled basement, bent streetlight poles, shattered ground on the hills above the Medical Center. I wandered inside, where I noticed the clock had stopped at exactly 6 A.M., the time of the earthquake; the bulletin boards told of planned events that never took place. I knew the geology well. I had been an exploration geologist for Shell Oil Company in southern California, and I had mapped the faults that turned out to be the source of the earthquake. During my Shell days, I had no idea these faults were earthquake hazards. No one else did, either. So I wrote research proposals and received funding from government agencies as well as oil companies to evaluate the earthquake hazards of the faults I had previously studied for their oil possibilities. Geologists are natural historians, accustomed to figuring out the past, but the next earthquake was in the future and we needed to learn something about which faults were dangerous and which ones were not. It was exciting, and it also gave my students and me a sense of purpose: not simply learning about geology for its own sake but trying to make a difference in people’s lives and their safety. We mapped the faults, and we published our papers. But after a while, I began to wonder whether it was more important to discuss earthquakes with my scientific colleagues or, instead, with my wife, my next-door neighbor, or the State vi Preface vii Legislature. This question answered itself when more earthquakes arrived. I always learned about these earthquakes from nonscientists. My barber and friend, Bob Minnick, told me about the Whittier Narrows Earthquake of October 1, 1987. Before I could catch my breath, TV stations and newspapers began to call me, and armed with virtually no information, I suggested that it was probably on the Whittier Fault. (It wasn’t.) I was heading home from work on October 17, 1989 when I heard on the radio about the Loma Prieta Earthquake. The phone rang nonstop until almost midnight, and I pontificated to the media that the earthquake had ruptured the San Andreas Fault. (It hadn’t.) Finally, on January 17, 1994, my wife Angela called me out of bed to look at TV reports of another big Los Angeles earthquake.. As I watched TV images of collapsed freeways, burning houses, devastated shopping centers, and a burning gas line on Balboa Boulevard, I once again was awestruck by the power of the very faults I was trying to understand. After the Northridge Earthquake, the phone kept ringing for several days because my students and I had mapped the faults in the area of the earthquake. I became a media resource (read: “talking head”), so along with my colleagues I was asked which fault had caused the earthquake. We were all wrong. It turned out to be an eastern extension of a fault that I had mapped, but I had published a paper saying that the eastern extension was inactive. However, the media’s interest in what I was doing made me wonder whether it was enough to publish papers on the faults we were mapping, communing only with my scientific colleagues. Nobody paid much attention to us until an earthquake struck, and then we were big news. As I talked to reporters and to my nonscientific friends, I came to the conclusion that Californians, like Oregonians where I now live, were woefully uninformed about earthquakes, and also not very interested—unless the earthquake struck where they lived. Telling people California has an earthquake problem is like telling them about carpenter ants in the basement or about high blood pressure and high cholesterol—they don’t really care until it happens to them. But the sheer size of the earthquake problem dwarfs other concerns we face: the possibility of thousands of fatalities and tens of billions of dollars in damage. Suddenly, earthquake science stopped being fun for me; as a scientist, I began to feel like the watchman on the castle walls warning about barbarians at the gate, begging people to take me seriously. viii Living with Earthquakes in California How could I convince people they ought to be taking more steps to protect themselves against earthquakes, just as they would against fire? The solution to my problem came at the university where I teach. Oregon State University had recently adopted a baccalaureate core curriculum that includes courses that synthesize and integrate student learning at the advanced undergraduate level. One of the components of the new curriculum is a course relating the discoveries of science to their impact on technology and on society. In 1995, I offered to teach a course that told the story of the scientific recognition of the earthquake problem in the Pacific Northwest and of how society responded to it in terms of legislation, building codes, insurance premiums, elementary school curricula, and individual and community preparedness. The course was first taught in winter term, 1997, to a large class on campus and also was televised on three cable channels in Oregon. The class notes written for this course served as the nucleus of a book, Living with Earthquakes in the Pacific Northwest, published by Oregon State University Press in 1998. The course drew students from across the University spectrum. I required a five-page term paper on a topic related to earthquakes. Although the prospect of reading nearly two hundred term papers was daunting, it turned out to be the most gratifying part of the course.
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