California scientists warn: Like it or not, the ‘Big One’ is coming
Fear of earthquakes is part of life in California. But people experience this anxiety in different ways. For some, the fear prompts them to take steps to protect themselves: strapping down heavy furniture, securing kitchen cabinets and retrofitting homes and apartments.
For others, the fear prompts denial — a willful ignorance of the dangers for years until the ground starts shaking.
Seismologist Lucy Jones has spent her career trying to understand public attitudes about earthquakes, with a focus on moving people past paralysis and denial.
Jones said the way experts like her used to talk about earthquakes wasn’t very effective. They tended to focus on the probability of a major earthquake striking in the next 30 years — the length of a typical home mortgage. They also took pains to say what they didn’t know, which she now believes allowed the public to tune out and hope for the best.
Now she is making a dramatically different point. She said that in a keynote speech to international scientists in Japan on May 21, she emphasized that a devastating earthquake will definitely happen, and that there is much the public can do to protect themselves.
Denial may be getting a bit harder these days. Over the past several years, a few California cities have taken dramatic steps to require retrofits of thousands of vulnerable buildings.
And next year, scientists and the U.S. Geological Survey are expected to unveil the first limited public phase of an earthquake early-warning system that would eventually offer seconds and perhaps more than a minute of warning through smartphones and computers.
There are several factors that make a peril especially frightening, Jones told a joint meeting of the Japan Geoscience Union and American Geophysical Union. She named three of the biggest ones, citing the work of University of Oregon psychologist Paul Slovic:
Something that cannot be seen.
Something that is very uncertain.
Something that seems unknowable.
“All of these trigger our primal fears of the unseen predator hiding in the jungle,” Jones said.
“We have literally evolved to be afraid of randomness,” Jones said.
“So we respond by trying to find the pattern. We evolved to find these patterns to infer that waves in the grass means a predator in hiding. We find patterns even when they’re not real,” Jones said. “We see constellations in the stars. When there is no pattern, we still try to make one.”
Rather than accepting the randomness, the public has turned to scientists to take the uncertainty out of future earthquakes, and researchers have spent much effort trying to find an answer.
There was some optimism in the successful prediction of the 1975 Haicheng magnitude 7.3 earthquake, in which people were evacuated before the quake struck in China, saving lives, Jones said.
A large part of the answer? There were more than 500 “foreshocks” to the big temblor, most of them in the 24 hours before the largest quake hit.
“The prediction did not happen because the Chinese knew more than we do about foreshocks. They used the basic principle ... quantified more than a century ago: One earthquake makes another earthquake more likely, and guessed that having a swarm of over 500 events made a big earthquake even more likely,” Jones said.
Officials in that region of China had more to gain by ordering evacuations because of the weakness of the buildings against earthquakes. And they had less to lose from a false alarm, given the political and economic system of China at the time, she said.
But the great guess of 1975 wasn’t repeated when California scientists tried to do the same thing in the central part of the state.
Scientists in California were so convinced of a seemingly logical pattern of earthquakes in the Monterey County town of Parkfield that they projected a 95 percent chance of another magnitude 6 earthquake happening between 1988 and 1993.
The scientists were wrong. It would be until 2004 before the quake hit. The model, it turned out, wasn’t always right.
And therein lies the great problem of being so obsessed with when the next big earthquake
will come — it wasn’t making us safer.
Publicizing the odds of a devastating earthquake in the next 30 years just didn’t translate well to the public.
Cities up and down California were doing little, if anything, about ordering vulnerable buildings to be strengthened or demolished before they collapsed in a future earthquake.
“Psychologists tell us that uncertain things are more frightening. Something that is frightening and uncertain is something we would like to ignore,” Jones said. So what could be done? Instead of asking themselves, “What does society want from us?” scientists began considering a separate question: “What does society need from us?”
So, in the case of earthquakes, Jones shifted the answer.
Jones said she learned to focus her talking on what she did know, rather than what she did not.
For one, she and a team of researchers published a scientifically plausible scenario of a magnitude 7.8 earthquake on the San Andreas fault that could cause many deaths and the collapse of numerous buildings.
Also, Jones said she learned to tell property owners they would have to pay for how their building fares in an earthquake — either as a retrofit or by picking up the pieces after the building collapses.