SOONER or later, America will suffer an earthquake as devastating as the one that has wreaked havoc on northern Japan. It could happen next week, next year or next century; it has happened on numerous occasions in the past, and will happen again. The best that can be done is to prepare for the inevitable, adopting measures that will help emergency teams rescue the victims and allow the recovery to proceed as rapidly as possible. But the chaos that ensued in the aftermath of Hurricane Katrina shows how unprepared America can be for disasters.

Earthquakes about as powerful as the magnitude 9.0 quake that shattered the coastal towns of northern Japan before drowning them with a 30ft tsunami have struck along the Oregon coast at least seven times during the past 3,500 years. The last time was on January 26th 1700. The precise date is known thanks to records kept by Japanese officials, who witnessed the devastation caused by the subsequent tsunami when it inundated their shores.

America's next mega-disaster is likely to be a smaller earthquake, but one much closer to a major conurbation than has occurred of late. That could happen almost anywhere—from Alaska and California in the west to Massachusetts, Missouri and South Carolina to the east. All have suffered considerable death tolls and damage as a result of large earthquakes in the past.

The problem today is that the last cataclysmic quake to strike a populated area in America—the magnitude 7.9 shock that destroyed much of San Francisco in 1906, killing some 3,000 people—is too long ago to have much of an impact on current thinking. The magnitude 9.2 quake and tsunami that struck Prince William Sound, Alaska, in 1964—the second largest seismic event to be recorded anywhere at that time—mercifully claimed only 131 lives, since so few people lived there.

Even the magnitude 6.7 Northridge earthquake that ripped through the Los Angeles suburbs in 1994, doing about $20 billion-worth of damage, left fewer than 60 people dead. The recent Japanese disaster is expected to have killed more than 27,000 and caused up to $300 billion-worth of damage.

Geologists in America fear that the lack of serious shaking in recent times has lulled those living in seismically active parts of the country into believing that their local building codes and disaster preparations are adequate. A computer simulation, called “ShakeOut”, undertaken by the United States Geological Survey in 2008—involving over 5,000 emergency responders and 5.5m citizens—indicated that a magnitude 7.8 earthquake unleashed on the lower end of the San Andreas Fault, some 40 miles east of Los Angeles, would cause 1,800 deaths, $113 billion in damage and nearly $70 billion in business interruption.

Partly in response to ShakeOut, the National Earthquake Hazards Reduction Programme (set up by Congress in 1977 to mitigate the effects of earthquakes) commissioned a body of scientists in 2008 to draw up a 20-year action plan for reducing the hazard of earthquakes in America. The National Research Council (NRC), which was charged with developing the plan, reported last week on the 18 tasks it reckons are crucial if the country's earthquake resilience is to be improved. Implementing the plan is expected to cost $6.8 billion over 20 years. That seems cheap. According to the California Emergency Management Agency, every dollar spent on preparation saves four dollars on reconstruction after a disaster.

One of the NRC's most important (and certainly most expensive) recommendations is a national earthquake warning system like the one Japan installed in 2007. Thanks to its network of 1,000 seismic stations around the country, Japanese authorities had nearly a minute to halt bullet trains in northern Japan (none was derailed) and warn local employers to stop lifts and switch off dangerous machinery. The seismographs detect the burst of “P-waves” emitted by an earthquake that travel at twice the speed of the more destructive “S-waves”, giving valuable seconds of warning depending on the distance from the epicentre.

But seismologists fear a national earthquake warning system is unlikely to be built in America because of complacency and the spending squeeze. Finding just the $50m needed to complete California's pilot network is proving hard enough—and Californians need no reminding how valuable such a system would be. Unlike the wary Japanese, when it comes to earthquake mitigation the majority of Americans remain unshaken and unstirred.