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Sunday, November 4, 2007

EARTH QUAkE : Living on a fault: Homeowners shake off quake risk

Earth quake :

While only a few people in the east foothills experienced the shaking so near the epicenter, the Sabins are hardly alone living close to danger. There are at least 369,000 more people living near three major faults - the San Andreas, the Hayward and the Calaveras - than during the 1989 Loma Prieta quake. That 6.9 temblor, centered in the Santa Cruz Mountains, killed 62 people and caused $6 billion in destruction.

The newer population .

estimate comes from a 24hoursNews review of U.S. Geological Survey fault maps and data collected in 1990 and 2007 by the U.S. Census Bureau and the California Department of Finance. It is almost certainly low.

It does not include the populations of unincorporated areas of Santa Clara, Alameda, Contra Costa and San Mateo counties. And it does not include the growth of cities such as San Jose and Palo Alto, only parts of which are within five miles of one of the faults.

But for perspective, those 369,000 people represent more than 40 percent of the total population growth in those four counties since 1990.

The most growth - more than 200,000 people - has been along the Hayward Fault, particularly in Milpitas, Fremont and Hayward - an area seismologists say could be primed for another big shake.

A tour of fault country, days after the Bay Area's strongest quake since Loma Prieta, took a reporter from the redwood-clad billionaire estates of Woodside to the sunny suburban hillsides of Fremont to the rural hills above San Jose, where somebody like Kathy Sabin can still have enough land to keep 47 animals near the nation's 10th-most-populous city.

Homeowner after homeowner, when asked why they moved so close to a known fault, said accepting earthquake danger is part of the bargain you strike in exchange for the incredible views, weather, culture and outdoor life of the Bay Area. None of them intends to move. And there is also a subtle psychological adjustment: It's not so much a discounting of earthquake danger, but a sense that other natural disasters elsewhere are somehow worse.

As a California native, "I'm kind of used to earthquakes," said Kathy Sabin. "I would be more afraid of a tornado or a hurricane."

If the East Coast and the Gulf Coast have their hurricanes and blizzards, and the Midwest its tornadoes and floods, earthquakes are "our" natural disaster. Even as they threaten us, they also seem to define who we are.

San Andreas Fault

Loaded with plywood building materials, the truck wound its way through the rural groves of Woodside, past gated estates, past women on horseback, past an aptly named "Why Worry Lane."

The center of Woodside is less than a mile from the San Andreas Fault, but there's a lot of construction. Town records say the value of building permits for new construction, additions and alterations is up 35 percent in 2007 over the same period last year.

Real estate agents can recount multimillion-dollar sales falling through because of a mountain lion in the back yard, but hardly ever due to the nearby fault.

Though people are aware of the fault, it has not hurt real estate values, said Jayne Williams, an agent with Coldwell Banker. She was speaking with a friend - Pam McReynolds of La Honda - in the Woodside center, across the street from where Williams had been during the Loma Prieta quake.

"We've grown up with it," Williams, a Woodside native, said of the fault.

Of course, Williams' sister moved to Cape Cod to escape earthquakes. But Williams and McReynolds said they wouldn't trade natural disasters with her.

Farther south along the San Andreas - even on Loma Prieta Way in the mountains above Los Gatos, where a wag might say you're asking for trouble - new homes are being built.

But asked for the most earthquake-safe place to build a house in the Bay Area, USGS seismologist Tom Brocher only chuckles.

"As a rule of thumb, if you're within five miles, you are going to be strongly shaken," he said.

"If I told you to live in San Ramon, you're living on the Calaveras Fault, or close to it. In Pacifica, you're on the San Andreas Fault. Almost all of us live within five miles or so of one of the major faults."

Brocher said people should consider the earthquake hazard zone disclosures amid the stack of papers they sign when they buy a home.

"All you want to do is sign and take ownership of the house," he said. "We would like people to pay attention to that. They should definitely be aware of the risk."

And where in the Bay Area does a USGS seismologist live?

Brocher said he chose his home in Millbrae as much for its flat lot - safe from earthquake-triggered landslides - and its distance from soil liquefaction hazards around San Francisco Bay, as for its relative proximity to a fault line. He's just 1.5 miles from the San Andreas.

"I told my wife, 'Look you're not going to have any view of the bay,' " he said.

Hayward Fault

A good chunk of the Bay Area's population wasn't living here during the Loma Prieta quake. Many weren't even alive. About 29 percent of the population of Santa Clara County is under 21 - too young to remember Loma Prieta even if they had been born in 1989.

So for many, the Alum Rock quake was a first. But not for Sandy Movahed. The Fremont resident definitely remembers 1989: The Loma Prieta quake demolished her office in San Francisco. And yet she bought a home with her husband a few hundred yards from the Hayward Fault. A court reporter who transcribed lengthy state hearings on earthquakes, Movahed knows plenty about the phenomenon. She is confident the Bay Area's strict building codes will provide some protection.

"Bottom line," she says, "nobody knows when there's going to be an earthquake."

And one more thing: Her sunny neighborhood under the grassy hills, which overlooks the silver sweep of San Francisco Bay, has "probably the most perfect weather in the world."

Calaveras Fault

At the epicenter of Tuesday's quake, nobody seemed too concerned about future quakes.

Don and Joann Reed said the Loma Prieta quake caused a mini-tsunami that washed right out of their swimming pool. This quake did nothing like that.

"We're on fractured rock here, and I hear tell that fractured rock is better for you than solid rock," Joann Reed said.

Living on the Calaveras Fault for 32 years, the retired couple dismissed the thought of moving to escape a quake.

"Earthquakes don't happen as often as the hurricanes, and the tornadoes and the floods and those bad electrical storms and the awful heat with the humidity in the summertime and the just intolerable cold in the wintertime," Joann Reed said of the troubled life elsewhere. "Here it's an occasional earthquake and the rest of the time it's just like heaven."

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