EL CERRITO, Calif. --
Underneath the fourth fairway at the lovely Mira Vista Golf and Country Club in El Cerrito
may lie the secret of one of America's next great disasters: The Hayward fault, one of the
most dangerous earthquake risks in the world.
"It's beauty and the beast," David Schwartz, a geologist at the U.S. Geological Survey, said. "We could be overdue for a big one."
For earthquake experts like Schwartz, the Hayward fault running along the east side of San Francisco Bay under the cities of Oakland and Berkeley is far more perilous than the more famous San Andreas fault a few miles to the west.
Scientists have estimated that the San Francisco area has a 67 percent chance of a major earthquake by 2020. And it is on the Hayward fault, they believe, that the stress between the North American tectonic plate and the Pacific plate is most likely to snap.
The area's last major earthquake, the Loma Prieta quake in 1989, which measured 7.1 on the Richter scale, saw elevated freeways pancake, houses tilt and part of a major bridge collapse. And Loma Prieta, which caused almost $6 billion in damage and killed 63 people, was centered on a stretch of the San Andreas fault 72 miles (115 kilometers) south of San Francisco--its destructive effects softened by the distance the shocks had to travel.
By contrast, the Hayward fault on San Francisco's doorstep has been dormant for too long, they say. "We really have been very lucky to live in a century where we've had unusually low earthquake activity in the Bay area. But we believe we are now coming out of the stress shadow of the 1906 earthquake," he said, adding that pressure clearly was building across the state's network of fault lines. "The weak links in the chain are beginning to fail."