1 Million Dead in 30 Seconds
Seismic risk mitigation is the greatest urban policy challenge that the world confronts today. If you consider that too strong a claim, try to imagine another way in which bad urban policy could kill a million people in 30 seconds. Yet the politics of earthquakes are rarely discussed, and when discussed, widely misunderstood. Take the Great East Japan Earthquake on March 11, which released 600 million times the energy of the Hiroshima bomb. The ensuing partial meltdown of the Fukushima reactor prompted international hysteria about nuclear power, but few seemed to realize that a far deadlier threat had been averted. As seismologist Roger Bilham has aptly put it, houses in seismically active zones are the world’s unrecognized weapons of mass destruction—and Japan’s WMDs didn’t go off. Its buildings—at least those that weren’t swept away by the accompanying tsunami, a force of nature against which we are still largely helpless—remained standing, and the people inside survived.
That so few buildings collapsed in the earthquake was a human triumph of the first order. It showed that countries can make great progress in seismic risk mitigation; in the Kobe earthquake of 1995, 200,000 buildings collapsed. But cities around the world seem happy to ignore the earthquake threat—one that is only growing as the cities themselves get bigger and bigger.
In January 2010, an earthquake struck Haiti and destroyed nearly 100,000 buildings. Hospitals, schools, government buildings, jails, hotels, churches, whole neighborhoods—all crumbled, entombing everyone inside. After the quake, I received an e-mail from a scholar of international relations. “It’s odd that earthquakes tend to occur frequently in countries that can least afford them,” she wrote.
You could only write such a sentence if you had never given the matter much thought. It isn’t odd; in fact, it isn’t true. Mother Nature doesn’t have it in for the poor. Rather, earthquakes come to our attention only when they are disasters, and they are disasters only when they strike dense urban areas full of badly made buildings. Last year, there were a number of earthquakes larger than the one that leveled Port-au-Prince, but they didn’t make the news because they happened in the middle of nowhere. California’s Loma Prieta quake, the “World Series earthquake” of 1989, was as big as the one in Port-au-Prince. It killed so few people by comparison—only 63—because San Francisco’s buildings and infrastructure were well designed and strong.
In the wake of the Kobe quake, Japanese engineers took extensive measures to reinforce buildings and infrastructure. They installed rubber blocks under bridges. They spaced buildings farther apart to prevent domino-style tumbling. They introduced extra bracing, base isolation pads, hydraulic shock absorbers. A minute before the March earthquake, automatic seismic monitoring systems sent warnings to Japanese cell phones. Elevators glided obediently to the nearest floor and opened. Surgeries were halted. Videos from Tokyo show skyscrapers swaying gracefully, like cornstalks in the wind. Not one collapsed.
Likewise, the aftershock that struck Christchurch, New Zealand, this past February was deadly, but the astonishing part of that story isn’t that several of the city’s buildings collapsed; it’s that most of them did not. The peak ground acceleration—a measurement of how much the ground shakes—was immense, one of the highest ever recorded. Something like that would have flattened most cities. New Zealand’s strict and well-enforced building codes saved Christchurch from annihilation.
But many of the world’s biggest cities are built more like Port-au-Prince than like Christchurch, and many are at massive seismic risk. Eight of the world’s ten biggest cities are built on fault lines. There is a reason for this: people like to live near water and fertile ground. Over the millennia, seismic activity creates coasts, valleys that channel water, temperate microclimates. The human mind doesn’t work on geologic time, so people rarely ask themselves how exactly these attractions came into being.
The odds of more Haiti-scale destruction are growing by the day because the world is urbanizing. Two hundred years ago, Peking was the only city in the world with a population of a million people. Today, almost 500 cities are that big, and many are much bigger. That explains why the number of earthquake-caused deaths during the first decade of this century (471,015) was more than four times greater than the number during the previous decade, according to statistics compiled by the U.S. National Earthquake Information Center. If the fatality trend continues upward—and it will, because the urbanization trend is continuing upward, as is the trend of housing migrant populations in death traps—it won’t be long before we see a headline announcing 1 million dead in massive earthquake. Indeed, we’ll be lucky not to see it in our lifetimes.
Just as we know how to build airplanes that don’t crash, we know how to construct buildings that don’t collapse. If you want to learn how to do it, grab some marbles and a Teflon baking sheet and follow the sixth-grade lesson plan on Discovery Online. We also know which cities are most at risk: Bogotá, Cairo, Caracas, Dhaka, Islamabad, Istanbul, Jakarta, Karachi, Katmandu, Lima, Manila, Mexico City, New Delhi, Quito, and Tehran. Los Angeles and Tokyo are prime candidates for a major quake, but they will probably survive, since they are well built—though L.A. could do better. New York is at greater risk than people realize. In 2008, researchers at Columbia University’s Lamont-Doherty Earth Observatory published a paper in the Bulletin of the Seismological Society of America noting, among other things, that the Indian Point nuclear power plant was sitting on top of two active seismic zones. The odds of a quake big enough to cause a Fukushima-like disaster there are small. The odds of a quake big enough to take down houses constructed under pre-1995 building codes are not. If you live in an old building—and particularly if you live near 125th Street, where the fault line runs—you might note that.
So we understand enough about seismology to be sure that certain cities face a high risk of earthquakes with enormous death tolls, and we understand enough about engineering and disaster management to say exactly what should be done to protect the residents of those cities. What we don’t understand—or rather, what we’re seldom willing to say plainly—is why some governments take the risk seriously and take aggressive steps to mitigate it, while others shrug and say, Que será, será.
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