California: The Big One is Going to Happen

May 29, 2017

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 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, emphasizing that a devastating earthquake will definitely happen, and that there is much the public can do to protect themselves.

Denial may getting a bit harder these days. Over the last 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. The system has been planned for years but still could be derailed by budget cuts proposed by President Trump.

Three factors that make something especially frightful

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.

Humans hate randomness

“We have literally evolved to be afraid of randomness,” Jones said at a recent conference in Japan.

“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,” she said. “We see constellations in the stars. When there is no pattern, we still try to make one.”

But there’s a problem

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 magnitude 7.3 earthquake in Haicheng, China, in 1975, in which people were evacuated before the quake struck, 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,” Jones said. “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.”

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.

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