Your City Might Not Be Ready for the Next Big Quake

More than 20 million people will take part in the Great ShakeOut today, raising awareness about earthquake risks. But it won't help unless we fortify vulnerable buildings.

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Robyn Beck / AFP /Getty Images

California students participate in a past Shakeout earthquake drill.

At 10:17 A.M. Pacific time today, millions of Americans around the country—and more people around the world—will practice for something they hope will never happen: a major earthquake. It’s called the Great ShakeOut, and it’s almost certainly the biggest disaster preparation drill in the world, involving some 24 million people working in schools, homes, hospitals and businesses. Started in California in 2008, the ShakeOut is meant to train people in how to respond to a major quake—if you’re indoors that means dropping to the floor, taking cover beneath a desk or table and holding on as securely as possible. You should also avoid any exterior walls, windows or hanging objects. Those outdoors should move to a clear and open area if possible, and avoid buildings and power lines that might fall on you.

Taking the right steps in the midst of a quake can mean the difference between life and death. But make no mistake—the death toll of a major temblor is mostly decided before it hits, not during. Cities that have invested in strong buildings can weather even the most devastating quakes, while cities that are caught off guard can see thousands or more citizens killed even by relatively weak temblors. And on the day of the Great ShakeOut, we need to realize just how many of our major cities—including ones here in the U.S.—are unprepared for the next big quake.

(MORE: The Money We Give to Quake Victims Could Be Better Spent Before Disaster Hits)

We can start with a city that should know better: Los Angeles. The second-biggest city in America is no stranger to quakes—over the past year alone, the city has experienced more than 100 quakes, most of them tiny. The San Andreas fault runs close to northeastern Los Angeles, and in 1994  a major quake centered in the city’s Northridge neighborhood killed 60 people. Every Angeleno knows that the Big One could happen any day.

But the benefit of that history is that L.A. is better prepared for a quakes, from well-drilled emergency personnel to strict seismic codes for new buildings. Better prepared—but not perfect. An investigation published in the Los Angeles Times earlier this week found that more than 1,000 old concrete buildings in Los Angeles and hundreds more throughout the country may be at risk of collapsing in a major quake. Concrete buildings can be particularly vulnerable during strong temblors, when about 5% of those structures typically collapse. That’s because concrete buildings are vulnerable to the sideways motion of a major quake, since they lack sufficient steel reinforcing bars to hold columns in place.  Just two years ago, a major quake in Christchurch, New Zealand—like L.A., a rich city accustomed to temblors—toppled two concrete office towers, killing 133 people.

Buildings could reinforce the concrete structures to help them withstand a major quake—but it wouldn’t be cheap:

“Will it be better safety-wise if you reinforce this? Will you help save lives? Yes,” said Martha Cox-Nitikman of the Building Owners and Managers Assn. of Greater Los Angeles. “But that’s easy to say — if you have money.”

Even more alarming, before the Times investigation, a team of researchers from the University of California-Berkeley produced a comprehensive list of potentially vulnerable concrete buildings in Los Angeles—but have not made the list public because, in the words of study leader Jack Moehle, “I don’t want to get sued.” Responding to the Times piece, Los Angeles Mayor Eric Garcetti said he was interested in making buildings safer, but he also worried about the city’s potential legal liability if they publicly identify vulnerable buildings. Of course, if you happen to live in one of those concrete buildings—and you can see a Times map here—that may be of little consolation.

(MORE: Aftershocks Could Raise Earthquake Risks for Vulnerable Cities)

But at least Los Angeles knows what’s coming. Scarier are those regions that have suffered major quakes, but only in the distant past, lulling them into complacency. You wouldn’t know it from recent memory, but the Pacific Northwest has experienced quakes as devastating as the 9.0 magnitude temblor that pulverized northern Japan in 2011. They’ve occurred very roughly every 300 years or so—and the last one was more than 300 years ago. It doesn’t help that cities like Portland and Seattle are built on sandy soils that liquefy when the earth shakes, causing buildings to lose foundation support. A 2010 study in Nature found that the Pacific Northwest had a 37% chance of being hit by a magnitude 8 or higher earthquake over the next 50 years, more than double previous estimates. That’s frightening, because the Northwest is simply not ready for a quake of that size.

And it gets worse as you look around the world. There are more than 380 urban areas with at least 1 million inhabitants—and as the pace of urbanization swells, that number wil only grow, as will the size of massive megacities like Tokyo, Shanghai, Bombay, Lagos and Rio de Janeiro. Human population density is the multiplier of disaster. The University of Colorado seismologist Roger Bilham has estimated that over 400 million people live in cities that face significant seismic hazards—many of them in relatively impoverished metropolises like Caracas or Panama City or Tehran, where the death toll from a truly massive quake could top 1 million. Bilham has said that in earthquakes, bad buildings act as “weapons of mass destruction.” On ShakeOut day, it’s important to remember that we need to do more than drop, cover and hold on to protect ourselves from the Big One.

(MORE: How Shoddily Constructed Buildings Become Weapons of Mass Destruction)