Scientists have never predicted a major earthquake. They do not know how, and they do not expect to know how any time in the foreseeable future. However, probabilities can be calculated for potential future earthquakes. For example, scientists estimate that over the next 30 years there's a 67% probability of a major earthquake occurring in the San Francisco Bay area. Scientists often focus their efforts on the long-term; lessening of earthquake hazards by helping to improve the safety of structures rather than creating short-term predictions.

      Changes in animal behavior before earthquakes have been observed and documented in different parts of the world, most recently in the northern California earthquake of October 17, 1989. It has been recor
ded that a fish in a high school biology lab in California would flip on its side before some earthquakes. Dogs, cats, snakes, and horses have also been known to behave strangely before earthquakes. But it's possible the change in animal behavior may be caused by other events. Also, the behavior is not consistent; sometimes earthquakes occur with no previous behavioral change.

      How to prepare for an earthquake?

     Perhaps an earthquake's greatest danger lie in the fact that it can occur almost at once. If you live in a location that's prone to earthquakes, preparation before the event is certainly key.

     To paraphrase the American Red Cross: "It's not the shaking that hurts. It's the stuff that falls on your head." Collapsing walls, flying glass and falling objects cause most quake-related injuries and deaths.

     Look around your house for things that could fall or move. Ask yourself what may happen if your cupboard doors fly open during a quake, allowing dishes or God-knows-what to fall across the floor. Is the TV and stereo fastened down and are shelves fastened to walls? Do you have hanging plants or light fixtures that might fall? Is there a heavy picture or mirror on the wall over your bed?

     Know the danger spots. Secure all tall and heavy furniture that could topple (倾倒) over, such as bookcases, china cabinets or wall units. Hang heavy pictures and mirrors away from beds, couches, and anywhere people sit. Keep breakables or heavy objects on bottom shelves.

     Stay clear of windows, fireplaces, or appliances if a quake hits; stay out of the kitchen--it's a dangerous place. In short, stay away from anything that could probably fall on you. Don't run downstairs or rush outside while the building is shaking, or while there is a danger of falling or being hit by falling glass or debris. Secure a water heater by strapping it to wall studs and bolting it to the floor. Define Your Safety Zone: against inside walls, under strong tables or desks, in stout(结识的)doorways.

      Keep food and water supplies on hand.  You should be prepared to take care of yourself and loved ones for a period of 72 hours. This is how long it is estimated for help to arrive, as they have to deal with the same predicaments as you. Have two places where everyone can meet. One will be you home, but you should have a second in case there’s a problem- It should be a safe distance from your house in case of a home fire, and a place outside your neighborhood in case you can't immediately return  Find out about earthquake plans developed  by your children's  school  or day care.  Remember, transportation may be disrupted.  Keep some emergency supplies--food, liquids, and comfortable shoes, for example--at work.