Seismologist: Southern Cal overdue for major quake
Pastor Dale Morgan
Seismologist: Southern Cal overdue for major quake *
'Here's how you're going to die if you don't change anything'
--Inland Valley Daily Bulletin, California
Article Launched: 08/11/2007 12:18:24 AM PDT
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?" Jones 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
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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."
How bad could it be
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