再When the catfish stirs, July 4th 2009 P27 (日本の地震リスク)

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再When the catfish stirs, July 4th 2009 P27 (日本の地震リスク)

 

Earthquakes, and the preparations for then, are metaphors for Japan's malaise. A capricious, mythical catfish lies beneath the Japanese archipelago. Usually the Shinto god of the earth keeps the brute's head pinned down with a granite keystone. But when Kashima drops his guard, the thrashings of the grotesque fish convulse the earth. Japan is extraordinarily prone to earthquakes, accounting for nearly a fifth of the world's supply of them. No city, not even Los Angeles, surpasses Tokyo for seismic action. With tsunamis and typhoons too, an acceptance of natural disasters is said to be hard-wired into the Japanese psyche. Tokyo sits near two fault lines, not one. South-west of the city, the Philippine Sea tectonic plate dives down under the Eurasian continental plate, bending the Eurasian plate down with it. From time to time, parts of that plate spring back, like a ruler bent over the edge of a desk and let go. The 8.3-magnitude Great Kanto earthquake in 1923 originated this way, killing 140,000 and causing scenes of devastation in Tokyo and the great port city of Yokohama, even nearer the epicentre. But potentially more catastrophic is the kind of earthquake that might well up from the depths immediately below the capital. There, not just the Philippine Sea Plate but the Pacific plate descends under the Eurasian plate on which Tokyo sits. New work suggests that a chunk 60 miles long and 15 miles thick appears to have broken off and got lodged between the two ocean slabs like a deer swallowed by a python. Its convulsions are thought to be the source of deep-thrust earthquakes throughout Tokyo's history, the last one in 1855. While other quakes ripple towards Tokyo like a rug being flicked, this kind pumps the whole city violently up and down, then side to side. The chances of a magnitude-seven quake are put at 70% in the next 30 years. A 7.3 shock beneath Tokyo, it is estimated, would cause $1 trillion of damage, which would be easily the most expensive calamity in history. Historical accident put one of the world's biggest cities (23m) on such dangerous ground. The victor of a late 16th-century civil war was the shogun of Edo, which became Tokyo, the imperial capital. Even today the population of greater Tokyo grows slightly while Japan's shrinks. More than six decades have passed since the last, destructive quake. Tremors every few weeks set pictures swinging and bookshelves rattling. But regularity lulls more than it alarms. Is Tokyo become complacent about the restless catfish in its depth? The metropolitan government insists not. Annual disaster drills are conducted. Building standards have been tightened. Roads have been widened to serve as firebreaks and emergency routes. Dense residential areas have been cleared in favour of high-rise developments. The long-range planning on which Japan once prided is still in evidence. Yet the building standards are not retrospective. The drills appear mainly for form's sake, a fun day out. Disaster education, mainly in the form of jolly cartoons, seems designed to play down the dangers. One third of Tokyoites polled some years ago said they did not even know an earthquake-warning system existed, and the government is loth to test it for fear of causing alarm. Exhortations for action - huddle together under a table during a powerful quake - might be for talismanic effect. Japan has long had a powerful construction lobby and a can-do attitude to building. But in retrospect many projects look hubristic. Huge urban developments have been built along Tokyo Bay, many on reclaimed land. Yet the soft alluvial sediment of Tokyo's low-lying areas, it is now understood, is vulnerable to liquefaction, in which violent movement turns the soil to quicksand. Tokyo ran up lots of tall buildings, which were thought to be safer than low ones because, though they sway alarmingly, they do not snap. But on soft soils, vibrations from long-period seismic waves are amplified, possibly exacerbating the swaying of skyscrapers. In truth, engineers' calculations have not been tested. Meanwhile the graft endemic to Japan's construction industry more or less guarantees that corners have been cut. Tokyo's quake of 1855 came just after the arrival of Commodore Matthew Perry and his “black ships” which forced Japan to open to the world. The two traumas were conflated. The 1923 quake and its economic consequences hastened military rule and war. The coming quake may reverberate politically, too, particularly affecting the public paternalism that prevails in Tokyo's approach to disaster management as in so much else. A disaster would expose the government's known shortcomings:its tendency to stress duty over flexibility;the squabbling and rivalry of its different departments;its lack of preparation. A recent earthquake drill in Shinjuku railway station, where up to 200,000 commuters might head after an earthquake in the hope of getting home, sounded warning. It was, says a senior Tokyo official, “a perfect-sounding drill, in a perfect world, but still a failure.” The problem was the absence of government staff (they will be off dealing with the graver emergencies). Nobody could agree whether they should lead or follow. If that sounds like a metaphor for Japan's current malaise, then perhaps there is a silver lining. Japan's paternalism, and the political apathy of voters that is its mirror image, has survived the cold war and an economic boom and bust. It may even survive the coming election, in which the Liberal Democratic Party may fall from power without the Democratic Party of Japan offering a clear alternative. No one could possibly wish a catastrophe on Tokyo, but thinking about it provides a clarity in which much more is demanded of Japan's political leaders.