Predicting the Unpredictable: The Tumultuous Science of Earthquake Prediction , Susan Hough Princeton U. Press, Princeton, NJ, 2010. $24.95 (260 pp.). ISBN 978-0-691-13816-9
Scientists who work in the fields of earthquake prediction and climate-change studies have something in common: They often find themselves in adversarial situations with amateurs. Why do people who barely know what an earthquake is think they can predict them? Says Charles Richter, “What ails them is exaggerated ego plus imperfect or ineffective education, so that they have not absorbed one of the fundamental rules of science—self-criticism.’
That quote is found in Susan Hough’s timely book, Predicting the Unpredictable: The Tumultuous Science of Earthquake Prediction , a comprehensive, broadly accessible, and readable overview of the ups and (mostly) downs of earthquake prediction over the past 50 years. A seismologist at the US Geological Survey, Hough has the rare gift of being able to write about highly technical subjects in an easy flowing, even slangy style that never seems forced, unnatural, or condescending. By also conveying in the book what the life of a seismologist is really like, she does an excellent job of presenting science as a human endeavor that scientists do and not just as a body of theory.
Hough does not shy away from dealing with the sometimes murky underworld of eccentric amateur earthquake predictors, who use such strange indicators as missing pets or aching toes; with the rise of the Web, such people now have the means to reach a wide audience. By including them, she rightly acknowledges their existence in the landscape of science as a social activity, even though their claimed predictive successes tend to fall apart under scrutiny.
She also discusses the case of Giampaolo Giuliani, the Italian lab technician who, using the unproven method of measuring radon gas emissions from the soil, predicted the magnitude 6.3 earthquake that struck the city of L’Aquila in central Italy on 6 April 2009. But Hough clearly shows why Giuliani’s prediction was unreliable. What transpired after the L’Aquila quake, though, came too late for Hough to include: Several of Italy’s top seismologists and earthquake engineers are facing possible charges of manslaughter for “not adequately conveying the seismic risk.’
In general, earthquake predictions cannot be treated in scientific isolation, away from matters of public policy. Hough raises the thorny questions of what responsibilities the seismologist has with respect to conveying warnings and how civil authorities should treat predictions. She retells the story of the 1970s prediction by Brian Brady that a massive earthquake would hit Peru in 1981; it never occurred, but the preparation that ensued led to economic losses. Hough also traces the swing in policy focus from prediction to hazard assessment: In properly designed buildings, people survive earthquakes, no matter when they strike. And yet earthquake prediction retains a public glamour beyond what current earthquake-hazard studies can match.
My main reservation with the book is that it is rather US-centric, as even the author admits. There is little discussion about the development of earthquake prediction in Japan, China, or Russia. Briefly mentioned is Greece’s VAN project (named for the three seismologists who pioneered it), which uses seismic electrical signals to predict earthquakes. However, that classic case—it led to a great debate in the 1990s among seismologists about whether earthquakes could be predicted—deserved a more detailed exposition.
I have a rather minor quibble with a photo in figure 10.2b, supposedly showing earthquake lights preceding the 2008 earthquake in Sichuan, China. The figure actually shows well-known atmospheric phenomena called sun-dogs and was taken nowhere near Sichuan. Also, I found one significant prediction technique missing: the use of shear-wave splitting to detect stress-induced alignment of microcracks in rocks. That technique claims at least one successful forecast of a magnitude-5.0 earthquake in Iceland in 1998.
Overall, Predicting the Unpredictable is a fine book, an enjoyable read from start to finish; the author steers a balanced, fair, and measured course between optimism and pessimism. Anyone who wants to know why earthquakes are still unpredictable will find the answer here.
