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The “Big
One,” as earthquake scientists imagine it in a detailed,
first-of-its-kind script, unzips
California’s
mighty San Andreas Fault north of the Mexican border. In
less than two minutes,
Los Angeles
and its sprawling suburbs are shaking like a bowl of
jelly.
The jolt
from the 7.8-magnitude temblor lasts for three minutes —15
times longer than the disastrous 1994 Northridge quake.
Water and
sewer pipes crack. Power fails. Part of major highways
break. Some high-rise steel frame buildings and older
concrete and brick structures collapse.
IN this January 17, 1994,
file photo, the covered body of Los Angeles motorcycle
officer Clarence W. Dean lays near his motorcycle which
plunged off Highway 14 overpass that collapsed onto
Interstate 5 in the San Fernando Valley section of Los
Angeles. In a joint publication of the US Geological
Survey and California Geological Survey, scientists for
the first time have written a script detailing the
devastation California would likely face if it were rocked
by a monstrous 7.8-magnitude earthquake. -- AP
Hospitals
are swamped with 50,000 injured as all of Southern
California reels from a blow on par with the September 11
attacks and Hurricane Katrina: $200 billion in damage to
the economy, and 1,800 dead.
Only about
700 of those people are victims of building collapses.
Many others are lost to the 1,600 fires burning across the
region—too many for firefighters to tackle at once.
A team of
about 300 scientists, governments, first responders and
industries worked for more than a year to create a
realistic crisis scenario that can be used for
preparedness, including a statewide drill planned later
this year. Published by the US Geological Survey (USGS)
and California Geological Survey, it is to be released in
Washington,
D.C.
Researchers caution that it is not a prediction, but the
possibility of a major California quake in the next few
decades is very real.
Last
month, the USGS reported that the Golden State has a
46-percent chance of a 7.5 or larger quake in the next 30
years, and that such a quake probably would hit Southern
California. The Northridge quake, which killed 72 people
and caused $25 billion in damage, was much smaller at
magnitude 6.7.
“We cannot
keep on planning for Northridge,” said USGS seismologist
Lucy Jones. “The science tells that it’s not the worst
we’re going to face.”
USGS
geophysicist Kenneth Hudnut said scientists wanted to
create a plausible narrative and avoided science fiction
like the 2004 TV miniseries “10.5” about an Armageddon
quake on the West Coast.
“We didn’t
want to stretch credibility,” said Hudnut. “We didn’t want
to make it a worst-case scenario, but one that would have
major consequences.”
The
figures are based on the assumption that the state takes
no continued action to retrofit flimsy buildings or update
emergency plans. The projected loss is far less than the
magnitude-7.9 killer that caused more than 60,000 deaths
last week in western
China,
in part because California has stricter building code
enforcement and retrofit programs.
The
scenario is focused on the
San Andreas Fault, the 800-mile boundary where the Pacific and North American
plates grind against each other. The fault is the source
of some of the largest earthquakes in state history,
including the monstrous magnitude-7.8 quake that reduced
San Francisco to ashes and killed 3,000 people in 1906.
In
imagining the next “Big One,” scientists considered the
section of the San Andreas loaded with the most stored
energy and the most primed to break. Most agree it’s the
southernmost segment, which has not popped since 1690,
when it unleashed an estimated 7.7 jolt.
Scientists
chose the parameters of the fictional temblor such as its
size and length of rupture and ran computer models to
simulate ground movement. Engineers calculated the effects
of shaking on freeways, buildings, pipelines and other
infrastructure. Risk analysts used the data to estimate
casualties and damages.
A real
quake would yield different results from the scenario,
which excludes possibilities such as fierce
Santa Ana
winds that could whip fires into infernos.
The
scenario: The San Andreas Fault suddenly rumbles to life
on November 13, 2008, just after morning rush hour. The
quake begins north of the US-Mexican border near the
Salton Sea and the fault ruptures for about 200 miles in a
northwest direction ending near the high desert town of
Palmdale about 40 miles north of downtown Los Angeles.
Scientists
chose the scenario because it would create intense shaking
in the Los Angeles Basin and neighboring counties—a region
with nearly 22 million people.
The
scenario will be released at a House Subcommittee on
Energy and Mineral Resources meeting in
Washington.
Here are
the major elements:
§
10 a.m.:
The San Andreas Fault ruptures, sending shock waves racing
at 2 miles per second.
§
30 seconds
later: The agricultural Coachella Valley shakes first.
Older buildings crumble. Fires start. Sections of
Interstate 10, one of the nation’s major east-west
corridors, break apart.
§
1 minute
later: Interstate 15, a key north-south route, is severed
in places. Rail lines break; a train derails. Tremors hit
burgeoning Riverside and San Bernardino counties east of
Los Angeles.
§
1 minute,
30 seconds later: Shock waves advance toward the Los
Angeles Basin, shaking it violently for 55 seconds.
§
2 minutes
later: The rupture stops near Palmdale, but waves march
north toward coastal
Santa Barbara and into the
Central
Valley city of Bakersfield.
§
30 minutes
later: Emergency responders begin to fan across the
region. A magnitude-7 aftershock hits, but sends its
energy south into Mexico. Several more big aftershocks
will hit in following days and months.
Major
fires following the quake would cause the most damage,
said Keith Porter, of the University of Colorado, Boulder,
who studied physical damage for the scenario.
The quake
would likely spark 1,600 fires that would destroy 200
million square feet of housing and residential properties
worth between $40 billion and $100 billion, according to
the scenario.
Once the
shaking stops, emergency responders would do a “windshield
survey” that involves rolling through neighborhoods to
tally damage and identify areas of greatest need, said
Larry Collins, captain of the Urban Search and Rescue Task
Force at the Los Angeles County Fire Department.
Collins
said the scale of the disaster means firefighters would
not be able to put out every flame.
“We’re
going to have to think about out-of-the-box solutions,” he
said. | 
