‘Big One’ scenario paints bleak economic picture

An earthquake with a magnitude similar to the one that recently rocked China is inevitable in Southern California and could cause about 2,000 deaths, injuries to 50,000 and $200 billion in damage if it happened today, the U.S. Geological Survey and the California Geological Survey warn in a new report.

In the study, “The ShakeOut Scenario,” being released today, scientists examine the effects of a hypothetical 7.8-magnitude earthquake along the San Andreas fault on the region’s physical infrastructure and economic and social systems.

“The question is not if but when Southern California will be hit by a major earthquake -- one so damaging that it will permanently change lives and livelihoods in the region,” the report says. “Unlike many other faults, the southern San Andreas fault produces no small earthquakes.”

The study, prepared by a multidisciplinary team that included scientists, government officials, emergency responders and utility experts, predicts that major freeways and rail lines would be severed. The fault crosses such major arteries as interstates 10 and 15.

“An earthquake of this size and scope is inevitable in Southern California, and we are simply not ready for it,” said Sue Perry, a U.S. Geological Survey staff scientist who contributed to the report. “An earthquake of that size could be the Katrina of Southern California.”

The scientists prepared a hypothetical model in which the quake occurs on Nov. 13, 2008, at 10 a.m., starting near the eastern shore of the Salton Sea and traveling northwest along the fault at two miles per second. A narrative, much like a movie script, depicts the “realistic outcome” of the quake.

The temblor would disrupt the movement of goods to and from major ports; manufacturing plants would halt production and face additional costs to transport goods out of the region; and hundreds of older commercial office buildings would crumble.

“Businesses forced to close have a domino effect,” the report says, “and as the chances diminish for regaining jobs or finding new ones, more and more people are struggling to rebuild their lives.”

The report predicts that financial institutions would face a growing number of loans in default as businesses collapsed and individuals gave up on recouping their losses. Competition for building materials and construction crews would be fierce. Widespread fires caused by the quake and disruption of water, power and gas supplies would add to the economic toll.

However, Perry said the Southern California economy appeared to be resilient and probably would recover.

“Though this would be an enormous disaster, unless a whole lot of things go wrong that we can’t hypothesize in this study, it looks like we’ll avoid the kind of long-term, decades-long economic downturn that characterizes a catastrophe,” she said.

There has not been a devastating temblor in urban California since the 6.7-magnitude Northridge quake in 1994, which killed 57 and caused about $40 billion in damage.

The report says Southern Californians “have the opportunity to work together to write this ending . . . through the decisions they make -- or don’t make -- to get ready for earthquakes.”

The recommendations include storing water, retrofitting buildings and strengthening infrastructure.

--

andrea.chang@latimes.com