Living in the quake zone

26 June 2005 | 17:06 Code : 5272 Geoscience events
Parts of downtown San Bernardino will resemble bombed-out London in World War II. A Mexican restaurant on Mount Vernon Avenue, popular with the city's...
Parts of downtown San Bernardino will resemble bombed-out London in World War II. A Mexican restaurant on Mount Vernon Avenue, popular with the city's movers and shakers, could collapse into a waist-high pile of rubble.

The historic county courthouse will rattle into a crumbling concrete coffin.

Those are not the apocalyptic predictions of some lunatic doomsayer.

It will happen, agree scientists at the U.S. Geological Survey, California Institute of Technology and Cal State San Bernardino.

It will happen unless officials take steps to reduce the danger posed by unsafe buildings, they say.

This month's earthquakes are a reminder that Southern California is among the most unstable places on the planet, where solid ground can suddenly erupt into a writhing, convulsing monster.

Grisly scenarios of devastation are not necessarily inevitable, those scientists say.

"Natural hazards are inevitable, but natural disasters are not,' said Lucy Jones, the geologist at the California Institute of Technology often seen on television. "Damage is the result of choices we make along the way. How much are we willing to invest now?' Familiar features

San Bernardino County is no stranger to big earthquakes, but the region has been amazingly fortunate.

In more than 50 years, the only earthquakes of magnitude 7 or greater in Southern California have been in this county.

Of course, as the largest county in the lower 48 states, there's plenty of room for those to occur far away from populated areas.

On June 28, 1992, a magnitude-7.3 earthquake centered near Landers, just north of Yucca Valley, rumbled across the desert, triggering a 6.2 quake near Big Bear Lake three hours later.

Then on Oct. 16, 1999, the Hector Mine earthquake, centered 47 miles east of Barstow and 32 miles north of Joshua Tree, put another scare into the region with a magnitude 7.1.

The most powerful Southern California quake since the 1857 Fort Tejon monster was a magnitude 7.5 near Bakersfield on July 21, 1952.

In San Bernardino and neighboring cities struggling to maintain their economic vitality, officials have faced a difficult life-and-death balancing act whether to aggressively protect public safety regardless of cost and consequences, or watch some businesses close their doors. Money woes

In most San Bernardino County jurisdictions, officials have decided that ordering retrofits for the most dangerous category of buildings would be economically devastating. Instead, they have rolled the dice against Mother Nature.

"E Street would be a ghost town,' said San Bernardino City Councilwoman Susan Lien Longville. In 1999, she joined a majority vote to repeal a city ordinance that required certain high-risk buildings to be modified. "Making retrofitting mandatory would have decimated those commercial corridors.'

Public safety also means having the tax base to pay for firefighters and police officers, she argued. Protecting against a disaster that may be decades away could reduce the city's ability to provide those immediate life-saving services, she said.

Buildings made of unreinforced masonry are almost guaranteed to collapse in a major earthquake and have been clearly identified and catalogued, as required by a 1986 state law. That type of construction was common until the 1940s. In aging cities like San Bernardino, Rialto and Fontana, such buildings are still home to numerous businesses.

Not counting those that have been demolished or retrofitted, there are 118 in San Bernardino, 20 in Colton, 85 in Fontana, 77 in Redlands, and 12 in Rialto, made of unreinforced masonry, according to this year's report compiled by the California Seismic Safety Commission.

The cost of making those buildings safe can be staggering for small-business owners and cash-strapped local governments. That was why the City Council agreed to repeal its tough retrofit ordinance, Lien Longville said.

Geologists who are familiar with San Bernardino's dangerous ground argue it's faulty economics to allow such buildings to remain as they are. Basically it's "pay me now, or pay me later.' And that payment later will be in both dollars and blood, they said.

Jones of Cal Tech was blunt about the danger of unreinforced masonry buildings.

"Those buildings will be complete rubble. You're taking a gamble that the (earthquake) will be long enough away that those buildings will be replaced,' she said. Risk factors

San Bernardino City Councilman Neil Derry agreed people should be made aware of the risk, but that government can only do so much.

"Even if we mandate retrofitting, it still won't happen if the retrofit costs exceed the value of the building,' he said.

Other scientists argue it makes far more economic sense to do the work before a disaster strikes.

"Communities can wait and deal with it all at once after the fact, or deal with it a little at a time and save some lives to boot, and reduce the recovery time,' said Fred Turner, a structural engineer with the California Seismic Safety Commission.

Even if buildings have to be demolished or businesses have to move, it's better than seeing people die, he argued.

"The difference between demolition (before a quake), and lives lost is enormous,' he said.

The existing San Bernardino ordinance only requires owners of the buildings to post a 5-by-7-inch sign that reads: "This is an unreinforced masonry building. Unreinforced masonry buildings may be unsafe in the event of a major earthquake.'

Occasionally, the private sector does see benefits to making buildings safer.

Some owners who worry about their property values have done the work without a mandate from the city.

Court Street Jewelry and Loan, at Court and E streets, is on the city's list of unreinforced buildings, but was retrofitted a few years ago, manager Eddie Salas said.

The previous owner had the building improved so he could get a better price for it, he said.

"So we're not coming down,' Salas said.

Of course the magnitude-4.9 quake near Yucaipa in mid-afternoon on June 16 got his attention, retrofit or not.

"I still feel a little shaky about it,' he said. "The guitars on the wall were swinging back and forth.'

A magnitude-7 quake would generate 100 times more shaking than the Yucaipa quake.

The steady growth in property values will eventually cover the short-term costs of improvements and makes retrofitting buildings an economically sensible thing to do, Turner said. Mandatory fixes?

Some cities, notably those with higher-income populations, have either made retrofitting mandatory, or have offered incentives and assistance.

Rancho Cucamonga mandated that its 18 unreinforced masonry buildings be improved. Upland has a voluntary program but has provided some financial, architectural and engineering assistance.

Still, according to the seismic commission report, cities in San Bernardino County and the county itself lag far behind the rest of California when it comes to taking care of unreinforced buildings.

Statewide, 69 percent of such buildings have either been improved or demolished. Cities in San Bernardino County have either improved or demolished problem structures at rates of 0 to less than 50 percent, with the exception of Rancho Cucamonga at 91percent.

Building codes have historically been tightened in response to major California quakes, including the 1933 Long Beach quake and the 1971 San Fernando temblor. That 1971 quake led to the Alquist-Priolo Earthquake Fault Zoning Act, which prohibits a house from being built within 50 feet of a fault.

Few people have any idea how close they are to the powerful fractures. A perfect example is the West Colony Community, a well-kept middle-class neighborhood in south San Bernardino between Hunts Lane and Waterman Avenue.

Running through the middle of the neighborhood is a wide, green ribbon of grass. In the evenings, it's a popular place for residents to stroll, or ride bikes or watch their children play at the park and ballfield.

Lurking just beneath the soothing grass is the San Jacinto fault, capable of lurching several feet in a single jolt and generating a magnitude-7 temblor. The greenbelt was created because of the 50-foot setback requirement.

"Lovely,' said Gabriela Riffel-Schneider, 31, when told what's under the neatly trimmed grass as she was out for an evening walk last week. "It would have been nice to know. Now we have something to think about.'

Standing next to her, Michelle Hawkins, 35, was also surprised.

"Oh well, what are we going to do? We can't be scared,' she said.

Indeed, single-family homes built to modern standards are thought to be the second-safest place to be in a major earthquake. The safest place would be outside away from any buildings.

Curt Tague, 33, was cognizant of earthquakes when he bought his house a few doors away from the fault, though he wasn't aware it was there. Concern over earthquakes is what led him to buy a single-story home.

"I guess you have to trust the building codes,' he said.

His family does have food stored in the garage and bought a plastic drum to store water.

"We didn't know. Now we're going to be dead for sure,' his wife Sandra joked. Danger lurks

The 1994 Northridge earthquake, at magnitude 6.7, killed 60 people and caused an estimated $20 billion in damage, making it one of the most expensive natural disasters in history. But it happened in a largely residential area with mostly single-family homes and would have been far worse if it had happened closer to urban Los Angeles.

Jones of Cal Tech said she wouldn't be thrilled living 50 feet from a fault, but said, "If I had two choices between a new house near a fault, or an old house being far away on soft soil, a modern house is way better.'

Today's San Bernardino Valley comprises an almost "perfect storm' of geologic risk factors.

It sits at the junction of three extremely dangerous earthquake faults, the San Andreas, the San Jacinto and the Cucamonga. The ground on the valley floor is made up of loosely consolidated soil holding tons of groundwater.

The San Andreas could screech more than 15 feet and pummel the region with a magnitude 8, similar to the 1906 San Francisco quake, with 1,000 times the ground shaking of this month's Yucaipa quake.

Not only will the lightly packed soil shake like a bowl of gelatin, the shock waves will convert the water-laden sandy soil into soft goo, in a phenomenon called liquefaction.

The San Andreas runs southeast out of Cajon Pass and turns east along the foothills of the San Bernardino Mountains, a stone's throw from Cal State San Bernardino, north San Bernardino and Highland.

The San Jacinto fault splits off from the San Andreas near the bottom of Cajon Pass and runs through the middle of San Bernardino Valley College, and right under the tall, sweeping Guthrie Interchange where Interstates 10 and 215 cross.

The 1926 Central Courthouse in downtown San Bernardino is made of reinforced concrete but could collapse in a major quake. The county will spend about $30 million for a major renovation and seismic retrofit starting in September 2006. The project is expected to take about three years.

And those familiar with local geology always hold their breath or offer up a little prayer when driving across the flyover from I-10 to I-215. The entire Guthrie Interchange, including the connector ramps, sits astride the San Jacinto fault.

A major retrofit of the interchange was done in 1994 by adding steel jackets to the pillars, sinking additional supports to bedrock, and adding steel cables to hold the road sections together.

But scientists still wish officials would find some way to deal with the dangerous unreinforced masonry buildings that still dot the urban landscape and would surely be destroyed when one of the nearby faults unleashes a killer quake.

Geology professor Sally McGill at Cal State San Bernardino has studied the nearby faults extensively.

"Just like after the Indian Ocean tsunami, people wondered why we didn't have a warning system,' she said. "I'm afraid after the next big earthquake in California, people will be saying, 'Why didn't we do something about those unreinforced masonry buildings?''

tags: QAZVIN

Your Comment :