Video: San Andreas Earthquake Simulation
http://www.wrightwoodcalif.com/disaster/SanAndreasEarthquake.wmvSoCal overdue for big quake to hit the San Andreas Fault
Andrew Silva and Andrew Edwards, Staff Writers
San Bernardino County Sun
It'll be bad. Hurricane Katrina bad. Likely worse.
Thousands dead. Buildings collapsed. Freeways severed.
Scientists for the first time are figuring out in great detail just how bad it will be when the southern section of the San Andreas Fault, roughly between Palmdale and the Salton Sea, cuts loose.
"One of our goals is not to say, `We're all gonna die,"' said Lucy Jones of the California Institute of Technology, who is leading the effort. "It's, `Here's how you're going to die if you don't change anything."'
Scientists, academics, utility companies and emergency planners have jumped aboard the project so they can figure out exactly what will happen and how to reduce damage or at least be better prepared.
"What if a community decided to enact this measure on their water system? What if we could prevent the spill of petroleum product when a pipeline breaks?" said. "Our goal is to get the discussion going, and see how our choices are affecting our long-term survivability."
A detailed report is expected next spring. In November 2008 the state will use that information to create one of the most ambitious disaster drills ever undertaken.
While 300 miles of the northern fault ripped in 1906, killing an estimated 3,000 people in San Francisco, and the middle part shook during the powerful 1857 Fort Tejon earthquake, the southern section of the fault hasn't popped since the late 1600s.
There were six earthquakes in the 900 years before that, and none in the past 300, Jones said, meaning the most devastating disaster in 100 years is long overdue.
That's why scientists got funding last year to study a potential magnitude 7.8 quake that would originate near the Salton Sea and race 200 miles up the fault to Lake Hughes, just west of Lancaster.
What has surprised scientists is the level of destruction the earthquake would cause in Los Angeles, even though the fault is 60 miles away.
Though they're refining the computer models, the shock waves could turn west at the Cajon Pass and blast into Los Angeles.
(A link to animation showing how the shock waves are expected to behave is available at
www.sbsun.com.)
That's about the same distance San Francisco was from the epicenter of the 1989 Loma Prieta earthquake. That magnitude 6.9 quake knocked down a freeway, severely damaged the San Francisco-Oakland Bay Bridge and killed 63 people.
A 7.8 quake would shake nearly 10 times harder.
And it would shake for minutes. The magnitude 6.7 1994 Northridge quake lasted only seven seconds but killed 60 people.
"The calculations of motion on a San Andreas earthquake surprised us with longer term motion than we expected," said Tom Heaton, a professor of engineering seismology at Caltech. "I think people will be unpleasantly surprised by how hard the shaking is."
Even though the shaking in Los Angeles wouldn't be as intense because of the distance, the city sits on a deep basin of sediment that will shake like a bowl of gelatin and prolong the event.
"There will be large low-frequency waves. The ground will shift 10 or 20 feet. The (high-rise) buildings will resonate back and forth, and the slow part of the ground motion is important to them," Heaton said.
Some researchers think it's possible some skyscrapers could collapse.
The scope of the disaster makes planning for emergency responders difficult at best.
Last year, when visiting the command center for firefighters who were then mopping up the Esperanza Fire, Gov. Arnold Schwarzenegger hailed the abilities of the state's firefighters and confidently proclaimed that a disaster on the scale of Hurricane Katrina could not happen in the Golden State.
But no matter how well-trained the state's firefighters and other emergency responders may be, Southern Californians who survive the "Big One" will need to make sure they have food, water and other supplies to stay alive without the aid of government agencies or relief organizations during the quake's immediate aftermath.
"Citizens need to be able to take care of themselves," said Denise Benson, director of the county's Office of Emergency Services.
John Amrhein, the San Bernardino County sheriff's emergency services coordinator, recommends having a week's worth of supplies. He said people living in hard-to-reach places like the San Bernardino and San Gabriel Mountains need to have enough supplies to hold out for at least two weeks.
Information is available at
www.daretoprepare.org.
"There would be so much damage down in the valley that they wouldn't have enough time to come up into (Lytle Creek)," said Sally Boyd, a Lytle Creek resident who for about two years has been a member of San Bernardino County's Community Emergency Response Team, or CERT.
CERT members train to assist government emergency responders during fires, floods and earthquakes. Boyd said the idea is that volunteers would be able to immediately assist their neighbors before officials arrive on scene.
For the first three days or so after a 7.8-magnitude quake along the southern San Andreas, sheriff's deputies would spend much of their time surveying disaster zones and figuring out how and where to deploy, Amrhein said.
Besides assisting evacuations, controlling crowds and keeping an eye out for looters, deputies would also be responsible for keeping the county's jail population alive and behind bars.
Regarding evacuations, people leaving areas with severe damage will probably have to seek safety close to home, since a serious earthquake could crumble overpasses and tear up streets.
"If that happens you're probably not going to go very far," Amrhein said.
Thousands of High Desert commuters will be stranded when the 15 Freeway through the Cajon Pass is cut. The fault could move 15 feet there, slicing the traffic lanes.
Estimates accessible from the Web site of the Governor's Office of Emergency Services show that across 10 Southern California counties, a temblor would kill 524 people if the quake began at 5 p.m.
Another 749 people would likely suffer possible life-threatening injuries.
Jones cautioned that those estimates are based on a limited database. There are thousands of pre-1975 concrete buildings that would likely fail, and if the quake happened during a weekday, the number of casualties could be staggering.
The report in the spring will include much better casualty estimates, she said.
Additionally, a quake would cause thousands of ruptures to water and natural gas pipelines and destroy more than 18,600 buildings, according to the estimate.
Arrowhead Regional Medical Center in Colton is designed to withstand an 8.3-magnitude quake, said Scott Smith, the hospital's disaster coordinator.
He said it's possible Arrowhead Regional could be the only hospital left functioning in the San Bernardino Valley after a major quake.
Whatever happens, Smith said Arrowhead Regional keeps a cache of emergency supplies and medicine locked away in case a disaster creates a surge of patients. The hospital has three mass-casualty tents that could provide temporary shelter for the injured.
The hospital has 120 cots on-hand for patients who could be treated inside the tents or within the facility's halls and lobbies. Patients and caregivers could also expect to have an independent water supply. Smith said Arrowhead Regional has a 750,000-gallon water tank.
San Bernardino is notorious for its number of unreinforced brick buildings, which would certainly end up as piles of rubble.
Steps need to be taken as soon as possible to reduce the damage and casualties, experts agree, but some solutions will be expensive.
"An earthquake is inevitable," Jones said. "Disaster is not."
Jones Contact writer Andrew Silva at (909) 386-3889 or via e-mail at
andrew.silva@sbsun.com.
Contact writer Andrew Edwards at (909) 335-9520 or via e-mail at
andrew.edwards@sbsun.com.
LOOKING AHEAD
The 200-mile southern section of the San Andreas Fault could generate a magnitude 7.8 earthquake. Among the consequences:
Thousands die, depending on what time of day the quake hits.
Hundreds or thousands of older buildings collapse.
Skyscrapers in downtown Los Angeles could be badly damaged and some may fall.
The 15 Freeway through the Cajon Pass will be severed,
stranding tens of thousands of High Desert commuters.
The 10 Freeway between Banning and Desert Hot Springs will
be cut, possibly in several locations.
The 14 Freeway north of Palmdale will be cut.
Some communities could go months without water.
Small businesses may fail if water and other utilities aren't quickly restored.
Pipelines will be severed, triggering fires and interrupting supplies.
Older hospitals may suffer damage, causing remaining hospitals to be swamped with casualties.
Source: Lucy Jones, California Institute of Technology
