(Bloomberg) -- At least half of the world's largest cities are considered at moderate or high risk of a major earthquake. Fears of the next “Big One” affect such major population centers as Tokyo, Mumbai, Jakarta, Mexico City, Manila, Los Angeles, San Francisco, Sao Paulo, Istanbul and Tehran. With the world becoming ever-more urbanized — almost two-thirds of the population will live in cities by 2050 — earthquake preparation is a massive long-term challenge thrust into the hands of short-term elected leaders. What steps should be taken today to protect people, companies and the economy from a threat so remote that it could strike once in a lifetime, if that?
While cities differ greatly in their preparations, many in fault zones are moving more urgently to revisit disaster plans in the wake of Japan’s harrowing 2011 Tohoku earthquake, which spawned a tsunami that triggered a nuclear meltdown and killed more than 15,000 people. Los Angeles is requiring owners of about 13,500 wood-frame and 1,500 brittle concrete buildings to strengthen them against earthquakes, and San Francisco is requiring retrofits of wood-frame apartment buildings that house a total of more than 115,000 people. In Peru, where the capital city of Lima has a perilous combination of unsteady housing built atop unstable soil, the national civil-defense institute holds nationwide earthquake evacuation drills as critics warn of mass fatalities in a major temblor. Japan, Taiwan, Italy and Mexico are among the earliest adapters of earthquake warning systems, which detect the first waves of a quake and enable rapid public warnings, via broadcast media and text messages to mobile phones, as well as automated slowdowns or shutdowns of vulnerable industrial and transportation systems. A system for the U.S. West Coast will get its first tests this year, though its longer-term viability will depend on securing funding. Improvements to Mexico City’s schools and other public buildings after a catastrophic 1985 quake meant fewer deaths in a September 2017 temblor, though it still killed almost 400 people.
Shaking is a fact of life. Earth experiences several hundred observable earthquakes daily, with a major one — magnitude 7 or greater — happening more than once per month on average. There even are so-called induced tremors, or small quakes caused by oil extraction and other human activities. Coastal cities in the seismically hyperactive “Ring of Fire,” including Tokyo, Jakarta and San Francisco, share not just proximity to fault lines and volcanoes but a soft and saturated soil that can amplify the destruction of a quake’s shakes. Seismologists were startled that the 1985 earthquake caused more than 5,000 deaths in and around Mexico City even though its epicenter was more than 200 miles (320 kilometers) away. Although scientists say major earthquakes are not increasing in frequency, the potential for damage is bound to rise when cities grow taller, denser and richer. There are 283 million people in metropolitan areas at some risk of being killed, hurt or evacuated due to an earthquake, according to global reinsurer Swiss Re.
Retrofitting cities that date back hundreds of years isn’t cheap or painless. The benefits are largely theoretical, while the cost to stretched budgets is tangible. Progress can seem excruciatingly slow. Los Angeles is giving owners of potentially at-risk buildings as long as 25 years to make improvements. San Francisco is letting its skyline grow taller and denser despite lingering doubt that high-rise buildings can be made quake-proof — and even though one of the city’s skyscrapers is sinking and leaning. In India, efforts to improve engineering and building code enforcement have mostly languished, leading one expert to lament the lack of “champions for seismic safety.” There’s worry as well in Turkey, where the government is criticized for undoing some earthquake-preparation measures it pledged after a 1999 quake killed at least 17,000 people. All that may explain the move toward early-warning systems, which could give people a tiny window — perhaps just seconds, but conceivably a minute or more — to evacuate buildings. Technology may come to the rescue with cheaper ways to warn those at risk: U.S. researchers are exploring how to employ the motion sensitivity and ubiquity of smartphones to create a massive network that would automatically detect earthquakes and issue near-instantaneous warnings.
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