Still Not Ready for the Big One

Jan. 17--Much has changed since the Jan. 17, 1994, Northridge earthquake.

Some hospitals have been rebuilt or retrofitted to roll with the shaking earth. Freeway overpasses have been strengthened with steel, giving them flexibility to move without collapsing. Building codes are stricter. Emergency crews have better training and equipment.

So is Southern California ready for The Big One?

"We have come a long way. We have done a lot. But we still have a way to go," said Lucy Jones, seismologist at the U.S. Geological Survey in Pasadena and newly hired earthquake adviser to the city of Los Angeles.

"We are never going to be perfectly ready."

For planning purposes, Southern California scientists have defined The Big One as a magnitude-7.8 earthquake on the San Andreas Fault that causes damage so massive it would dwarf that of the Northridge quake, with a projected 1,800 deaths, 50,000 injuries and $200 billion in damage. That scenario has been the basis of the Great Shakeout drills that are held every year at schools, hospitals, businesses and other facilities throughout the state, and worldwide.

Seismologists insist a temblor of that size is a realistic possibility. Historically, the world has seen dozens of earthquakes larger than 7.8, while California has seen at least two -- San Francisco in 1906 with a 7.9 and Fort Tejon in 1857 with a 7.9, according to state records.

As the ShakeOut website warns: "It's not a matter of if an earthquake of this size will happen -- but when. And it is possible that it will happen in our lifetime." The shaking would last for nearly two minutes and be felt throughout the region -- Coachella Valley, the Inland Empire, the Antelope Valley, San Gabriel Valley and elsewhere.

Emergency service personnel frequently practice for such a catastrophe during large operations. Some, like the Great Shakeout, are pure training efforts that bring diverse public service and rescue agencies together, to practice setting up command centers and establish communications links with a myriad of operations, said Steve Ruda, a battalion chief for the Los Angeles Fire Department.

Other large-scale training exercises are real events, like the Los Angeles Marathon, he said.

These are important, both for the teamwork and multi-agency communications skills required to work them. They also provide real emergencies that need prompt solutions, said William J. Dunne, administrative director for emergency preparedness, safety and security services for the UCLA Health System.

Growing Apathy

While public safety professionals hone their skills, residents in the greater Los Angeles area have gone somewhat apathetic, surveys show.

Although more than 60 percent of Californians have learned how to be safe during an earthquake and what supplies they should have on hand, less than 35 percent have learned how to make their home structure safer or how to safeguard their finances, according to the California Earthquake Preparedness Survey, conducted by the UCLA School of Public Health in 2008.

Public safety officials consider some of the grades given out in that report disturbing:

B- Only 40 percent of Californians have made family disaster plans.

B- Less than 20 percent have participated in neighborhood disaster planning.

B- Only 40 percent keep the recommended minimum of three gallons of water stored per person.

"One of the things that we have clearly been successful on is the number of people who know to drop, cover and hold on," said Linda B. Bourque, founder and senior adviser for the UCLA Center for Public Health and Disasters.

Immediately after an earthquake, interest in preparedness soars for a couple of years, she said.

Then it wanes.

Ruda and other public safety officials hope the publicity surrounding the 20th anniversary of the Northridge quake will rekindle earthquake preparedness among Southern California residents.

Some of that is based on his own experiences.

Ruda, a Northridge homeowner when the earthquake hit, recalls crawling down the hallway of his home during the quake and when it stopped he ordered his three children to come to his voice.

The family had earthquake kits for all, which included water, food, clothing and shoes -- most of which was stored beneath beds.

Once the initial shaking stopped, family members put on their street clothes and shoes and went outside with many of their supplies.

He then went to work.

Ruda said because his wife and three children had their immediate needs cared for, they could help others in the neighborhood.

Retrofitted Bridges

The 79 bridges in the Los Angeles area that were retrofitted prior to the 6.7-magnitude Northridge quake sustained only minor damage, said Caltrans spokesman Mark Dinger.

"Since then, Caltrans has further bolstered more than 1,100 additional bridges statewide after taking into account information learned from that quake and other factors," he said.

"Bridges in Los Angeles and the rest of the state are now designed to safeguard the public against earthquakes most likely to occur over the next 1,000 years."

"Engineers design bridges to withstand the ground forces likely to occur over a certain period, rather than design for the magnitude of a particular quake," Dinger added.

Building Codes

Codes protect the employees and contents of the huge warehousing industry that dominates the Inland Empire and still has a significant presence in Los Angeles County.

The state-mandated building codes effectively ensure that the walls of these enormous "tilt-up" buildings are "tied together" with the roofs, said Gil Estrada, building official for San Bernardino County.

"There may be some cracks and bending, but hopefully (through these structural engineering improvements) buildings will not come down, buying time for employees to exit," he said.

But the progress is not all in straight line.

Recently Los Angeles has come under fire for allowing a number of buildings to be built over the Hollywood and Los Angeles faults, Bourque said.

"As building codes improve and more buildings remain standing during earthquakes, the relative importance of nonstructural damage increases," says "The ShakeOut Scenario," a 2008 document which examines in detail the implications for a magnitude-7.8 earthquake on the Southern San Andreas Fault, between the Salton Sea and Lake Hughes.

"The closer to a fault, the stronger the shaking," said David Oglesby, a professor of geophysics at UC Riverside.

The geographic structure of the area along the fault can mitigate or worsen the effects of the shaking, with soft, water-saturated soils increasing earthquake damage the most, said Oglesby, who focuses on the physics of earthquakes.

The often-congested intersection of the 215 and 10 freeways is directly on the San Jacinto Fault, he said.

Still in development is a system that scientists are hopeful they will be able to give the public earthquake warnings, of perhaps 10 seconds to a minute, prior to the arrival of a quake, said Mark Benthien, spokesman for the Southern California Earthquake Center, a network at USC of over 600 scientists, students and others at over 60 institutions worldwide.

"While that doesn't sound like very much (time), it's enough to get under a desk, stop elevators, begin the slow-down of a train, shut off equipment and industrial processes," Benthien said.

Copyright 2014 - San Bernardino County Sun, Calif.