Drop, Cover, and Hold On

This week let’s get straight to the scary part: The building you’re in starts shaking, hard. What do you do?

Standard advice on this has evolved somewhat over the years, but currently there is a consensus of expert opinion that Drop, Cover, and Hold On is the best procedure to follow. If you’ve been studying earthquake preparedness then today’s posting will be old hat, but if you’re new to this pay attention because this is one of the most important things to learn.


The first action is Drop, which means you literally drop down to your hands and knees. If the shaking that has just started turns out to be The Big One the chances are very high that you are going to end up on the floor one way or another. Your only choices are (1) Being knocked off your feet by the shaking and possibly cracking your head on the sharp corner of something as you fall, or (2) Dropping to the floor quickly and safely under your own control. Option #2 is better.

When should you drop? Right away, as soon as the first shaking starts, because big quakes can start small and your first indication that this is going to be a big one might be a painful collision between you and something hard. Where should you drop? Right where you are, because trying to move anywhere else puts you at risk of getting thrown to the ground before you get there.

What if nobody else drops? Won’t it be embarrassing to be the only one on your hands and knees? Probably, but let’s put it bluntly: Would you rather be embarrassed or bleeding? Besides, those other people looking at you may not be laughing at you at all. To illustrate this let me relate a personal incident: During an earthquake many years ago I crawled under my desk at the first sign of shaking, while everyone else in the room just stood there. After a few seconds the shaking stopped and it became apparent that the quake was very minor, not even strong enough to knock over a coffee cup, and I started feeling silly for hiding under my desk. Right about the time I was going to say something, another person in the room said “Boy, we all feel pretty silly standing out here in the open while you’re safe under the desk.” Please take that as a lesson to always take care of yourself, and let anyone who doesn’t follow your lead worry about feeling foolish.


While the situation may be different in certain other parts of the world, in areas like California which enforce strong building codes the primary hazard during a big earthquake is stuff falling on you. The solution is to get something between you and the falling stuff. The best barrier is a strong table or desk, but use whatever is handy — a chair, a book, a laptop computer, anything you can grab. If nothing suitable is nearby, use your arms and hands to form a barrier over your head and neck.

Don’t waste time looking for a perfect barrier, because it’s more important to get under cover quickly. Dangerous stuff can start falling with no warning, and running around the room looking for cover makes a bad situation even worse. Use whatever cover you have within easy reach.

Hold On

Assuming you do get under something like a table, the last step is to Hold On. Why do you need to hold onto something as big and heavy as a table? Your intuition tells you that it’s very stable and unlikely to move much, and under normal circumstances that would be correct.

Alas, an earthquake is not “normal circumstances,” and that table is likely to move, possibly by as much as several feet. If you’re wondering how a table can suddenly go sliding across a room, a physicist would probably tell you that technically it’s the room that suddenly goes sliding around under the table, but even for physicists that distinction is irrelevant if you’re the person under the table. Either way you look at it, your best strategy is to ride it out by holding onto your cover to keep your head and body protected.

Am I exaggerating things? Judge for yourself:

This is one of the best earthquake simulator movies I’ve found anywhere. It runs for a little less than 5 minutes, first showing an entire building to give you an idea of the magnitude of the motion, and then focusing on each room one at a time so you can see the effects. As the video shows the individual rooms, pick out the mannequins in each one and watch their heads. That should be enough to convince anyone of the importance of preparing. As a bonus, if you watch it all the way through you can see a refrigerator do a 180° pirouette.

Things you should NOT do

Don’t run outside. That’s about the worst thing you can do, because there is a good chance that dangerous debris falling from higher parts of the building will reach the doorway just as you do, and the debris and your head will try to occupy the same space at the same time. In this situation physics will win, and your head will lose.

Don’t stand in a doorway. That advice actually made sense back when we lived and worked in very old buildings, but it’s been a long time since our structures were made of adobe, and with modern building methods the only thing special about a doorway is that you’ll be clobbered by the door if the shaking slams it shut.

Don’t look for a “triangle of life.” This idea was proposed some years ago and has propagated via email all over the web, but it is based on experience in areas very different from California. Most experts feel that it’s a bad idea that makes you less safe.

Learn by doing

First let’s do a little video review:

OK, you’re all set now, right? No, not really, because if all you do is read this blog post and watch the video, you’re still not going to remember the information when you need it. A drill like this is like riding a bicycle; you have to do it and get some “muscle-memory”.

So do it. Let go of the mouse, take your hands off the keyboard, and crawl under whatever table or desk you’re in front of right now to see what if feels like.

No, really, I mean it. Go ahead and do it. Right now. I’ll wait.

Right. I was watching, you know, and a few people did it but most of you didn’t. Perhaps you need a bit more structure, camaraderie, and social support. Well, it turns out that we can provide all that: That big earthquake drill that Mr. Henson just mentioned takes place every October in the U.S. and other countries, and you’re invited! Next week I’ll describe how it works and how you can get involved.

For more information

For those who are physically unable to Drop, Cover, and Hold On, please refer to
http://www.shakeout.org/downloads/DropCoverHoldOn_AFN_090615.pdf for modified instructions.

For more details such as what to do if you are driving or in bed, there is a whole website dedicated to today’s topic at http://www.dropcoverholdon.org. I highly recommend you go visit it sometime because it’s filled with great information. Better yet, do it right now while you’re thinking about it, and we’ll see you back here next week.