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The Big One: Scientists Say the East Bay is Overdue for the Largest Earthquake in Centuries. And We're Not Prepared.

A Hayward Fault shaker will be way, way worse than 1989's Loma Prieta quake.



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Four major gas transmission lines near the Hayward Fault are potentially vulnerable to rupture, according to Melissa Subbotin, a PG&E corporate-relations officer. She says the company's top priority for immediately after an earthquake is locating leaks and remotely turning off gas lines as needed. She says the company runs a fleet of ten specialized vehicles fitted with methane-detecting technology that can pinpoint gas leaks under the sidewalk. These vehicles cruised the streets of Napa following that city's 2014 earthquake and will certainly be deployed in the East Bay when the Big One hits.

Five major freeways cross the Hayward Fault, as well. But according to a report from Caltrans, seismic upgrades have been completed on nearly all of more than 2,000 bridges and over-passes. In theory, they should now be protected against collapsing.

It is unclear whether the Tesoro and Valero oil refineries on the shore of San Pablo Bay are seismically stable. Neither company returned emails to discuss these issues.

Zoback, for one, believes these facilities represent a serious health and fire hazard. "The fault runs right by them, and they have miles and miles of pipes," she said, adding that she would appreciate some transparency from refinery managers.

"Everyone else, from Caltrans, to PG&E, to East Bay MUD, to BART — all of the other infrastructure owners — have made big investments in seismic upgrading, and we just don't know anything about those refineries," she explained.

Hudnut says the nature of the Hayward Fault makes it, from one point of view, less dangerous than other faults. Yes, it has the capacity to pack a destructive seismic punch. Yes, it runs through a heavily developed urban zone. "But we're fortunate in a way with the Hayward Fault, because we know exactly where it is, because of fault creep," he said. "Other faults don't experience fault creep and aren't so easy to pinpoint, but with the Hayward Fault, we know exactly what buildings it runs through."

In Sacramento, state officials are taking the risk of an extremely deadly earthquake in California very seriously. The governor's Office of Emergency Services has three earthquake-specific plans. One focuses on the aftermath of an earthquake on the Cascadia subduction zone, an ocean-floor fault running from Northern California to British Columbia. John Rundle, a distinguished professor of physics and geology at UC Davis, says the Cascadia subduction zone experiences a magnitude 8 to 8.5 earthquake every two-hundred to three-hundred years on average.

"It's now been more than 300 years since the last one, so it isn't inconceivable that we could get a large tsunamigenic earthquake in the next 20, 30, 50 years," said Rundle, who has helped design an earthquake-forecasting system for the consulting group at "It's definitely something we should be concerned about."

Seismologists have warned that a large earthquake on this fault will cause a tsunami about as deadly as Japan's 2011 catastrophe, which killed more than 10,000. Most of the impacts would occur north of Sonoma County.

The OES also has a Bay Area Catastrophic Earthquake Plan, which provides a framework for bringing outside assistance to impacted areas in the aftermath of a significant fault rupture. First, neighboring towns will help communities. Then, neighboring counties will help, and then the state, and finally, if necessary, federal agencies. The OES will conduct this cooperative relief effort, according to deputy regional administrator Ryan Arba.

The City of Oakland too has an emergency plan for when things go haywire. The strategy basically prepares for the worst-case scenario: 1.8 million Bay Area households with no running water, 300,000 people are left homeless, and 7,000 are dead.

Earthquakes and Human Nature

In the aftermath of such an earthquake, the City of Oakland's top focus will be protecting people. "Our [No. 1] priority is life safety, followed by protection of property, the environment and return of a healthy economic state to the City of Oakland," the Fire Department's emergency manager Cathey Eide wrote in an email. Even traumatized pets, she said, are a concerning issue.

Eide also explained that officials recognize the possibility that crime could be a problem immediately after an earthquake. More than that, however, she says they expect a natural disaster to bring the community together.

And although Sitar at UC Berkeley thinks looting and home break-ins could surge post-quake, he agrees that society will not entirely break down. "Not all the roads will be out, not all the bridges will be down," he said.

But what if your home experiences significant damage?

The state formed the California Earthquake Authority in the wake of Northridge, and the group, while not a state agency, is essentially a not-for-profit insurance company that educates the public, mitigates disaster, and insures homeowners.

The group's executive director is Glenn Pomeroy, and his job is to at once "not indulge in fear tactics," he says, but also focus on how "the risk is real" when it comes to the Big One in the Golden State.

"It's human nature to not internalize the fact that it's going to happen again," he explained of why people neglect to prepare. Yet then he reminded that the odds are not in our favor:

"The scientific community says there's a 99.9 percent probability of a 6.7 or greater happening in California in the next thirty years," he explained. And, if you narrow it down to Northern California and the Bay Area, there's a 76 percent of a 7.0 in the next thirty years, he said. "And a 7.0, as odd as it sounds, is three times stronger than a Northridge 6.7." And Northridge in '94 did $40 billion worth of property damage, half of that to homes.


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