Shake, rattle and live

The Sierra Madre earthquake, which struck at 7:43 a.m. June 28, 1991, was centered near the Sierra Madre fault zone in the San Gabriel Mountains and was considered relatively mild, registering at magnitude 5.8 on the Richter scale. Still, two people died — one man in Glendale was felled by a heart attack — and 100 people suffered mostly minor injuries. Total damage: $40 million, most of it to buildings with unreinforced masonry.

Then came the magnitude 6.7 Northridge quake at 4:31 a.m. Jan. 17, 1994. Because of the early hour and the Martin Luther King Jr. holiday, few were driving, at work or in school. Even so, 57 lives were lost, nearly 1,500 people were injured and property losses and other damages totaled more than $12.5 billion.

How could all that death and damage have been mitigated? How many lives and how much property might have been saved through training and preparedness? Those are some of the questions that scientists and emergency preparedness officials will be trying to answer on Nov. 13, when Southern California becomes the site of the largest earthquake drill in US history — the Great Southern California ShakeOut.

Event organizers the Earthquake Country Alliance, a public-private partnership of earthquake professionals, emergency managers, government officials, and businesses and community leaders, are centering their high-magnitude ShakeOut Scenario on the southernmost 200 miles of the infamous San Andreas Fault, an area between the Salton Sea and Lake Hughes, in the Lancaster/Palmdale area, that is the most likely source of a very large quake — possibly one larger than the one envisioned for the drill.

Covering Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego and Ventura counties, the ShakeOut scenario — which will occur at 10 a.m., when lots of people are at work, school or out in public — estimates 1,800 deaths, half occurring as a result of fires that would follow the quake.

How extensive the damage will be is unknown, but remember the firestorms of October 2007? The minimum estimated damage from those events was $40 billion to buildings and $25 billion to the contents of those structures.

Southern California hasn’t had a really big shaker since 1952, with the magnitude 7.3 Kern County quake. In all of California, that was outdone only by the San Francisco earthquake of 1906. The Richter scale wasn’t invented until 1935, but scientists believe that quake — which according to some estimates killed between 3,000 and 6,000 people — would have measured between magnitude 7.7 and 8.3.

More recent disasters paint a chilling picture of what could happen when a similar size quake hits a densely populated region. On May 12, a magnitude 7.8 earthquake hit Sichuan, China, killing 69,136 people.

In the fictional earthquake scenario, about 750 people will suffer severe injuries, requiring immediate medical attention, and about 50,000 people will require emergency room care. The death rate could be higher if hospitals are damaged or transportation is unavailable. Businesses would be interrupted, resulting in a loss of $50 billion in economic activity, with an estimated total loss of $213 billion.

US Geological Survey Multi Hazards Initiative Chief Scientist Lucile Jones, who last week hosted a media briefing on the upcoming drill, said that during the initial phase of a disaster, studies have shown that people “tend to turn to each other and help” and it’s “a couple of weeks after the event that you see the consequences of the breakdown of law and order.”

“This is a summation of years of research,” said USGS geophysicist Ken Hudnut, who helped author the report “The ShakeOut Earthquake Scenario — A Story that Southern Californians Are Writing.”
“In the past, we always talked about The Big One, but in vague terms,” Hudnut said recently. “We realized we had to get into the details.”

Recent events have also infused project leaders with a sense of urgency. “In China, they’ll be recovering from that for a long time,” said Hudnut. “With the [ShakeOut Scenario], there will be a deep and prolonged impact, but there will be things that will make it a quick and better recovery.”
The hypothetical earthquake will hit on a Thursday morning, beginning just north of the US-Mexican border, near the Salton Sea, then travel through the Coachella Valley and make its way to San Bernardino and Los Angeles one minute later. The report describes train derailments, bursting pipelines, power lines falling and all major roadways being impacted to some degree by 55 seconds of severe shaking. To put that time in some perspective, the Northridge temblor lasted seven seconds.
Hudnut, a visiting associate professor in geophysics at Caltech, said that Hurricane Katrina and its aftermath were also on the minds of everyone working on the scenario. The 2005 hurricane that destroyed much of New Orleans left 1,836 people dead, and the region still hasn’t recovered economically.

“We not only brought in earthquake expertise, but also engineering and economic expertise — we looked at it across the board,” Hudnut said.

Pasadena has a major role in the ShakeOut. Caltech and Art Center College of Design are members of the Alliance’s ShakeOut steering committee along with the USGS, the California Office of Emergency Services, the California Seismic Safety Commission, the Southern California Earthquake Center and the city of Los Angeles.

Registration to participate in the ShakeOut is free and open to everyone at www.ShakeOut.org.
Other planned events include: Los Angeles Earthquake Get Ready rally (Nov. 14), the International Earthquake Policy Conference (Nov. 12-14), Golden Guardian Emergency Response Exercise (Nov. 13-19) and Take One More Step (Nov. 14-16).