The Myth of Solid Ground

THE WHOLE OF EARTHQUAKE PREDICTION grows less distinct the more I try to hold it in my mind. It's a constant back-and-forth between predictors like Shou and Berkland, with all their "common sense" intuitions, and the seismologists who insist that there's more to the subject, that what appears logical on the surface often fails to hold up. When I call the USGS to ask about Shou's theory, for instance, Lucy Jones tells me the very idea is fallacious. "Earthquakes," she declares, "happen 10 kilometers below the surface. You can't create a cloud down there." Jim Mori agrees, although he's somewhat gentler, noting that, as with Haicheng, there have been reports of ground vapors associated with earthquakes. Still, he suggests, "If it were so obvious, it should be obvious. A lot of temperature changes would have to take place at ground level to make large clouds, and we haven't seen them. There's quite a bit of monitoring going on, and it's hard to believe we're missing all that stuff." Berkland, for his part, evokes a stronger reaction, as typified by Tom Heaton, who says in a voice thick with annoyance, "Jim Berkland has made many claims about his ability to predict earthquakes. He's made these claims for 25 years, and we've had lots of earthquakes. If the relationship between tides and earthquakes was that straightforward, it would be hard to suppress." Of all the scientists to whom I mention Berkland, only the Carnegie Institution's Paul Silver responds with anything less than exasperation. "His hypothesis is not outrageous," he admits, "in the sense that tides do deform the Earth," but he goes on to dismiss the theory anyway, citing the recent findings presented at the American Geophysical Union as proof.

Silver's take on this particularly interests me, since he's the one mainstream seismologist I've talked to who seems to share anything of the predictor's point of view. When I press him on the issue of water levels and displacement, however, he calls it inconclusive, telling me that "what we have to do now is enter the phase of really measuring deformation" -- the way the USGS sought to do in its investigations of Parkfield or the Palmdale Bulge. The problem, Silver says, is that even if you accept phenomena like water anomalies or animal behavior as valid, they are indirect indicators, and, as such, only measurable in scattershot fashion, which doesn't let us "understand the role precursors play as an earthquake develops, or to correlate them with other precursors to get a sense of seismic strain." More useful would be a system of measuring strain directly, which, he believes, has become increasingly viable with the advent of high-tech tools like sensitive seismometers to mark small, previously untraceable earthquakes, or global-positioning systems, which literally allow geologists to see deformation over a wide area by recording subtle variations in distance between sensors on the ground. The idea of bypassing secondary evidence to go right to the source is a compelling one, and it begins to suggest a context in which earthquakes might be credibly predicted after all. But as Silver talks, I find myself drifting once more amid all the old polarities, finding in his argument elements of both Berkland's notions of tides and ã deformation, and the more pragmatic efforts of the USGS and Southern California Earthquake Center scientists, who have lately begun to adapt similar technological innovations to their own, nonpredictive ends.

Ultimately, that feeling of suspension, of Ping-Ponging back and forth between the possibility of prediction and its opposite, may be the only thing we can count on. It emerges in even the most basic seismological discussions, such as the current debate over how earthquakes begin and end, whether large and small earthquakes are qualitatively different or are, instead, related in rather intimate ways. "One thought people have," explains USC's Tom Henyey, "is that little earthquakes grow into big earthquakes," that as a fault starts to slip, it builds up momentum, which either abates if the fault "catches itself" or ends up accelerating into a sizable quake. "The more we study with good recordings and good data," he elaborates, "the more we're beginning to believe that this is how most earthquakes operate" -- which suggests that, even if we could reasonably determine when an earthquake might be coming, its magnitude would be anybody's guess. Because of these uncertainties, Lucy Jones believes that we'd be better off focusing on developing a sustainable society, instead of the crisis-management culture we currently have. "What we need," Jones says, "is a way to live with earthquakes. We need to build buildings that won't fall down. We need to be able to deploy the necessary resources, even after an earthquake takes place. Whether or not we can predict them, earthquakes are going to come. This is something you live with by preparing, and we need to be prepared."

Without question, Jones is right about the importance of preparation. Even Berkland and King stress the need for precautions, and many predictors lament the hopelessness of making forecasts they know will go unheeded. "I know something's going to happen," King says in an unguarded moment, "and nobody will listen. People will die, and there's nothing I can do." Yet whether you see prediction as just another pipe dream, or you're like the out-of-town screenwriter I've heard about who checks in with a predictor friend whenever he's planning to visit California, preparation can come in a variety of forms. There's physical preparation, and there's its psychological counterpart, and while I wouldn't sacrifice the former for the latter, I also wouldn't say the latter doesn't count. In some ways, it all comes back to geopoetry, for if an earthquake, any earthquake, has something to teach us, it's that both our best and worst endeavors often pale to insignificance in the face of the processes of the planet, the inevitable stress and shear of the Earth as it slowly reinvents itself. This is what McPhee's geologist meant when he talked about the liberating aspects of deep time, and in spite of all the inconsistencies, the logic flaws and false alarms, I can't help thinking that it's what the predictors provide us also, a form of psychic strategy, as if by allowing us for a moment a way to mitigate our uncertainty, they have given us an emotional barrier against the impermanence of life along the fault.