Predicting the Unpredictable: The Tumultuous Science of Earthquake Prediction - Softcover

Hough, Susan Elizabeth

Softcover

ISBN 10: 0691173303 ISBN 13: 9780691173306

Verlag: Princeton University Press, 2016

Inhaltsangabe

Susan Hough traces the continuing quest by seismologists to forecast the time, location, and magnitude of future quakes - a quest fraught with controversies, spectacular failures, and occasional apparent successes. She brings readers into the laboratory and out into the field with the pioneers who have sought to develop reliable methods based on observable phenomena such as small earthquake patterns and electromagnetic signals. Hough describes attempts that have raised hopes only to collapse under scrutiny, as well as approaches that seem to hold future promise. She recounts stories of strange occurrences preceding massive quakes, such as changes in well water levels and mysterious ground fogs. She also ventures to the fringes of pseudoscience to consider ideas outside the scientific mainstream, from the enduring belief that animals can sense impending earthquakes to amateur YouTube videos purporting to show earthquake lights prior to large quakes.

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Über die Autorin bzw. den Autor

Susan Elizabeth Hough is a seismologist with the Southern California Earthquake Center and a fellow of the American Geophysical Union. Her books include Richter's Scale and Earthshaking Science (both Princeton).

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"Sue Hough, in fine style, has written a fascinating history of one of the most vexing problems in science. Anyone who has ever wondered why geophysicists can't predict earthquakes should read this book."--Thomas H. Jordan, director of the Southern California Earthquake Center

"Irresistible optimism, exciting drama, scientific puzzles, risky investments, outright fraud, wise and wacky characters. Why does earthquake prediction attract them like no other science? And what about triumphant success? Susan Hough tells the story in this balanced, well-crafted, readable, and compelling book. I recommend it for anyone, especially those bold enough to enter the field."--David D. Jackson, University of California, Los Angeles

"A new book on earthquake prediction written by an accomplished seismologist is long overdue. There is something in Hough's book for everyone--from the nonspecialist with a general interest in the topic to the earthquake scientist looking for new perspectives and a bit of insider history. This is a book that is, quite literally, hard to put down."--Greg Beroza, Stanford University

"In this well-written account, Hough examines the elusive and controversial question of short-term earthquake prediction. Those living in quake-prone areas simply want to know when scientists will be able to predict the next (big) one. Hough's excellent account provides context and insight into why this seemingly straightforward question has both fascinated and frustrated researchers for so many decades."--Mark Zoback, Stanford University

"A highly entertaining and accurate book. As Predicting the Unpredictable makes clear, cutting-edge science is often untestable in the short term because the data have been pushed as far as possible and beyond, and because the research is often conducted by scientists guided by intuition."--John Vidale, University of Washington

"This book is significant and new. Hough's research into the history of earthquake prediction--its difficulties, efforts made, and errors committed--is well done. I don't think there are any competing books on the market."--Max Wyss, director of the World Agency of Planetary Monitoring and Earthquake Risk Reduction

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Predicting The Unpredictable

The Tumultuous Science of Earthquake Prediction

By Susan Elizabeth Hough

PRINCETON UNIVERSITY PRESS

Copyright © 2010 Princeton University Press
All rights reserved.

ISBN: 978-0-691-17330-6

Contents

Preface to the Paperback Edition, vii, 
1. Ready to Rumble, 1, 
2. Ready to Explode, 12, 
3. Irregular Clocks, 29, 
4. The Hayward Fault, 39, 
5. Predicting the Unpredictable, 47, 
6. The Road to Haicheng, 58, 
7. Percolation, 86, 
8. The Heyday, 96, 
9. The Hangover, 108, 
10. Highly Charged Debates, 125, 
11. Reading the Tea Leaves, 141, 
12. Accelerating Moment Release, 150, 
13. On the Fringe, 158, 
14. Complicity, 171, 
15. Measles, 191, 
16. We All Have Our Faults, 196, 
17. The Bad One, 206, 
18. Whither Earthquake Prediction?, 222, 
Acknowledgments, 231, 
Notes, 233, 
General Index, 255, 
Index of Earthquakes by Year, 261, 

CHAPTER 1

Ready to Rumble

What is most tragic is that the collective genius of all of these experts, combined with the sensors and satellite observations and seismographic data and all the other tools of science and technology, could not send the important message at the key moment: Run. Run for your lives.

— Joel Achenbach, Washington Post, January 30, 2005

At the beginning of 2005, U.S. Geological Survey geophysicist Bob Dollar was keeping a routine eye on data from the local Global Positioning System (GPS) network in southern California, and something caught his eye. A small army of GPS instruments throughout California tracks the motion of the earth's tectonic plates; the movement of the North American Plate south relative to the Pacific Plate as well as more complicated, smaller-scale shifts. Plates move about as fast as fingernails grow; like fingernails, the movement is not only slow but also steady (fig. 1.1). But it seemed to Dollar that a group of stations out in the Mojave Desert and some in the San Gabriel Valley northeast of central Los Angeles had started to take a bit of a detour from their usual, steady trajectories.

When one uses GPS data to determine precise locations the results always reveal some flutter, the consequence of measurement imprecision or data processing complications. Knowing this, Dollar did not jump out of his chair. But, interest peaked, he continued to keep his eye on the results, waiting for the apparent detours to prove to be part of the usual noise.

They didn't. After a couple of months of watching and waiting, the hiccups took shape, defining what Dollar calls "hockey-stick curves." Which is to say, the data from a number of stations, formerly tracking along straight lines, had bent abruptly and were now tracking along different lines. It was enough to get any self-respecting earthquake scientist's attention. Dollar started to think that he "might be looking at something important." What the results meant, he wasn't sure. At a minimum, departures from steady GPS trajectories are unusual, and therefore interesting. But several lines of evidence suggest that this kind of anomaly, essentially abrupt and unusual warping of the earth's crust, could be a harbinger of a future large earthquake.

Earthquake predictions emerge from the pseudo-science community not unlike locust plagues in the desert: not like clockwork, exactly, but often enough. In these cases seismologists can speak to the media with confidence. At best, these sorts of predictions rely on methods that might (emphasis here on might) have an underlying shred of validity — for example, the notion that tidal forces might influence earthquakes — but have never proven useful for reliable earthquake prediction. At worst they are total hooey. But every once in a while the earth puts out signals that get scientists' attentions, leading us to wonder, is the Big One coming?

Arguably the biggest unanswered question in earthquake science is this: what, if anything, happens in the earth that sets a big earthquake in motion? The answer might be, "nothing." Earthquakes might pop off in the crust like popcorn kernels, at a more- or-less steady rate, leaving us with no way to tell which of the many small earthquakes will grow into the occasional big earthquake. If this is the case, too bad for earthquake prediction. But at least some theories and bits of evidence suggest that earthquakes might have a detectable launch sequence.

The last great earthquake in California was over one hundred years ago. The 1906 San Francisco earthquake was recorded on a handful of early seismometers around the world, and geodetic surveying measurements made before and after the quake led directly to one of the most fundamental tenets of earthquake science. The theory of elastic rebound describes how earthquakes happen as a consequence of stress accumulation. The theory of plate tectonics, developed a half-century later, explains how and why stress accumulates. In short: plates move, the edges stay locked, the surrounding crust warps, eventually the edges (faults) move abruptly to catch up. But if the earth sent out any subtle signals that the 1906 earthquake was on the way, they were lost forever, no instruments in place to capture them.

In recent years, scientists have developed and deployed increasingly sophisticated instruments to capture signals from the earth, not only earthquake waves but also minute warping of the crust. If any subtle signals are generated prior to large earthquakes, these instruments stand ready and waiting. Data have been recorded prior to a number of recent moderate, magnitude 6–7, earthquakes in California. And they have revealed no sign of precursory signals. This negative result has led some earth scientists to conclude that there is nothing to be revealed; that, in effect, earthquakes have no launch sequence. But we have yet to see the likes of the 1906 San Franciscoearthquake caught red-handed by a dense, close-in array of modern instruments. So seismologists are left to wonder what, if anything, the instruments will reveal when the next Big One strikes. Thus when instruments reveal something outside the ordinary, we are left to wonder, could this be it?

In early spring of 2005 Dollar brought his hockey-stick curves to the attention of local GPS experts. They were not immediately impressed. One geophysicist confessed that her first thought upon seeing the curves was, "What did we do wrong?" Scientists who study GPS and related data are not simply inclined toward self-doubt; they have learned to not get too excited about apparently unusual signals. GPS instruments essentially record time signals from satellites, and scientists use these signals to determine locations. The processing is notoriously complicated and capricious for a number of reasons, including the fact that the raw data have to be corrected very carefully to account for the orbits of the satellites. The results that Dollar had been looking at were from rapid — essentially quick and dirty — solutions. When researchers analyze GPS data for scientific investigations the raw data are processed more carefully. Not uncommonly, glitches in quick solutions disappear when more sophisticated processing is done.

Dollar's hockey sticks refused to flatten out. Eventually the results came to the attention of other colleagues, not GPS gurus but rather seismologists, and they took note. Where Dollar had been thinking he might be looking at something important, some seismologists wondered if they were looking...

Details zur Ausgabe

• Verlag: Princeton University Press
• Erscheinungsdatum: 2016
• Sprache: Englisch
• ISBN 10: 0691173303
• ISBN 13: 9780691173306
• Einband: Taschenbuch
• Anzahl der Seiten: 280
• Kontakt zum Hersteller: Princeton University Press; https://press.princeton.edu/books; ; 7th Floor, New South Building; PRINCETON; NJ; 8544; USA
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