We’re All Shook Up : Quaking over quakes won’t help--but being constantly prepared will

In the aftermath of the June 28 Landers and Big Bear earthquakes have come a multiplication of fears and fancies about what might occur next--”the reckless arithmetic of rumor,” as a forgotten writer once called it.

Both the U.S. Geological Survey and Caltech say they have been getting a lot of calls from people worried about an increased and maybe even imminent risk of a major quake in Southern California. The to-the-point response to these concerns is that no responsible authorities have ordered or recommended an increased state of public alert based on knowledge of what may be near. Nor, say the seismologists, have they detected any meaningful precursors--like suddenly falling water tables, to take one specific example--that might indicate a major quake is imminent.

Seismology, of course, remains an evolving science. Its most productive opportunities for expanding knowledge come when quakes occur. Though there may be good bases for offering informed speculation, there is still no way to forecast actual risk with any degree of certainty. There is a strong expectation that a major quake--the “Big One”--will take place in Southern California within the next 30 years or, some now say, a lot sooner. But an expectation, even one based on a consensus of experts, isn’t the same thing as a sure bet.

Realistically, of course, Southern Californians ought to be prepared for the Big One. It may not come within the lifetime of anyone now living; it could come in the next five minutes. Self-interest argues for being as ready for it as possible. That means public agencies should have constantly updated plans for taking emergency actions. It means having emergency supplies of food, water and first aid equipment in the home, in the car and at work.

Even in the absence of the Big One we can expect to experience some Pretty Big Ones in the months and years ahead, along with a lot of relatively Not So Big Ones. That includes the probability of significant aftershocks--in the 5 to 6 magnitude range--from last month’s big temblors. That likelihood may be what’s helping feed the rumors that Caltech and the Geological Survey are hearing from a nervous public in search of reassurance or, if not that, at least a timely warning to hide under the dining room table. The experts can knock down the rumors, but that’s about as far as they can go. In all probability they’ll find out about the next earthquake at just about the same moment the rest of us do.