Richard Allen, Berkeley Seismological Laboratory/UC Berkeley:
So, we always get asked what should you do in an earthquake. And the answer is you should get under the nearest sturdy table that you can find. There's a lot of misinformation out there about what to do. For example, a lot of people think you should get into a doorway. Well, that comes from the times when we used to live in adobe buildings and in adobe buildings, mud brick buildings, the most sturdy portion of the house was often a sturdy wooden door frame. Of course that's not the case anymore, so you don't get in the doorway.
The other thing that a lot of people have heard about is the triangle of life. That's actually been discredited in California and the reason is, most buildings in California are not expected to collapse and because of that, the biggest hazard that you face in an earthquake is debris falling from the ceiling. Ceiling lights, tiles, and whatever may be attached to the ceiling, so by getting underneath a table as quickly as possible is the best way of reducing the effect of the earthquake on you personally.
Learn more about the Berkeley Seismological Laboratory.