A Bounce of Prevention
In anticipation of 'the Big One,' Japan is using a mobile earthquake simulator as part of its preparation program
THE only warning for Ichiro Uchibaba was the odd behavior of a bear, a neighbor's pet, all excited in a cage like an old alarm clock gone berserk. Seconds later, at just before noon on Sept. 1, 1923, the earth lurched, and all of Tokyo was jolted with a ferocity that Mr. Uchibaba will never forget.
Roof tiles went flying, pillars toppled, fires erupted, and Uchibaba was thrown to the ground. The bear, which had somehow sensed the quake coming, reached out of the cage and scratched Uchibaba's arm.
"There was no place for me to escape that quake," he recalls. "I crawled to a moat and clung to a stick until it was over." Eight years old at the time, he witnessed the destruction of Tokyo as the city was consumed by flames over three days, taking the lives of 140,000 people, including his parents. The quake's intensity was later estimated to be 7.9 on the Richter scale.
The seismic upheaval was an experience that Uchibaba, as head of a group of remaining survivors, and the government do not want the Japanese to forget.
Only by keeping alive the memories of the 1923 disaster do officials hope to alert the Japanese to do more than just wait around for what is often called "the Big One."
As a reminder of the disaster, Uchibaba keeps a clock in his home set to the exact time of the 1923 quake. And every Sept. 1, he and other survivors go to a Buddhist temple and museum built to recall the great quake.
Also on Sept. 1 every year, millions of Japanese take part in "disaster prevention" drills run by local governments. School kids put on quilted headgear and practice getting under their desks. Old folks are reminded to choose a spot to meet loved ones in case they are separated. Stores sell emergency kits of water, flashlights, and preserved Japanese food, such as pickled plums.
The Japanese need few reminders. They know that their archipelago sits at a point on the Pacific rim where three plates of the earth's crust are colliding inch by inch, producing 30 or 40 "felt" quakes a year. Geologic instability is part of daily life in Japan. The word jishin (earthquake) is murmured with dread at every tremor.
If another big quake should hit the Tokyo area, which is now home to one-quarter of Japan's population, it would not only affect Japan but also create aftershocks on world financial markets as the Japanese withdrew overseas investments to pay for reconstruction at home.
Around 10 years ago, many Japanese seismologists predicted that a big earthquake was possible in an area just south of Tokyo within the next few decades. An "earthquake counter-measure" law was passed to improve evacuation roads, strengthen school buildings, and construct shoreline embankments against quake-generated tidal waves.
AND to really keep people on their toes, an "earthquake simulator" was invented and put on traveling trucks. The vehicles are open on one side and contain a typical Japanese kitchen. People are invited to step in and be rocked back and forth with a rising intensity, like a raft going down rapids.
"You must not think earthquakes are fun," yells one simulator-keeper, Katsumi Hirayama, to a gaggle of giggling school girls as they are jolted. He instructs them how to turn off the gas and get under a table. For taking a shake, each girl receives a packet of vacuum-packed rice crackers to keep as emergency food.
The mock quake is not always convincing. "When a real one comes, I won't live anyway. So why bother?" says Jun Murayama as she steps off the truck. "Even experienced swimmers can drown."
Since 1980, the Japan Meteorological Agency (JMA) has placed more than 130 sensors inside mountains and on the ocean floor to pick up geologic vibrations that might signal an earthquake in the region south of Tokyo. The electronic data are monitored by computers and two persons, 24 hours a day.
But the ability to predict a quake by scientific means has not been proved. "We don't know if we will succeed. But can we afford not to try?" says Dr. Nobuo Hamada, the center's deputy head.
If unusual signals are detected in several places, six prominent seismologists would be rushed to the agency. If all agree that a quake is imminent, they would then ask the prime minister to call for people to evacuate the most vulnerable areas.
Since 1923, the government has set strict construction codes to make buildings, bridges, dams, and other structures as seismic-proof as possible.
Some new buildings have "rubber feet" in the base to absorb shock. A few skyscrapers have a flexibility that allows them to sway for an hour after a tremor.
Yet no one knows for sure if all the structures were correctly built, or whether the designs themselves will actually work.
"We just don't know," says Chikahiro Minowa, chief engineer at a government quake-simulator center outside Tokyo. The center, built in 1970, uses a 180-ton floating table to test the seismic-resistance of new architectural designs.
"It's difficult to test a whole structure," he adds. "We'll just have to wait for a big earthquake."
Japan's most active constructor of high-rises, Kajima Corp., has invented a device to reduce the sway of tall buildings during a quake. A four-ton mass of steel sits atop an 11-story experimental structure in Tokyo and helps to "suppress" sway by quickly moving in the opposite direction with computer-driven hydraulics.
"Previous ideas were to protect buildings," says Akiko Oda, a company official, "but now comfort is pursued."
Quake-veteran Uchibaba says all the precautions are useless.
"The effects of the next quake will be much worse because of the way we live today. Cars will jam roads, gas stations will explode, and people won't be able to move.
"Japan is not ready for another quake, not at all. Even if you prepare, the real thing is different from anything that you can expect," says one who has lived to tell about it.
Next week: Earthquake engineering research at the State University of New York in Buffalo, N.Y.