How to be a neurotic, part 1: Earthquakes

[Originally posted on robjsoftware.org before I created robjthoughts.org.]

I've lived in the San Francisco area since 1990. That means I got here just after the last really big (e.g. people-killing big) quake. So I've never lived through a properly large one.

But now I've got a family. And that's naturally making me considerably more concerned about what will happen when a big one hits.

Quakes are one of the kinds of risks that are almost maximally difficult for the human psyche to cope with. We're optimized for managing risks that are very present and very tangible, and that we can take direct action to confront here and now. But earthquakes aren't like that. On any given day a Northern California quake is extremely unlikely to happen. Put together enough days in a row, though, and the probability (eventually, over decades) approaches 1.

So when I worry about quakes, I have to reconcile the fact that one will eventually happen with the fact that it almost certainly won't happen today.

And of course, as an engineer, I have to get quantitative about it. Hence, I'd like to present this engineer's guide to (relatively mild) earthquake neurosis.

Step 1: Quantify

The actual odds of a quake happening are extremely difficult to calculate. The figures are usually something like "50% chance of a big one sometime in the next 20 years." What are you supposed to do with that? There's basically no way to use that number.

But the quantification you can do is around what will happen if a quake does hit while you are:

• at home in bed
• driving around your neighborhood
• commuting to work
• at work in the office
• walking down the city street

All of these have different threat profiles. For me, the most nightmarish scenario is actually if one happens while commuting to work.

You see, my commute involves BART, the local rapid transit train system. I spend about 80 minutes per day on BART. And the real clincher, the real "pucker factor" element (in fighter jock speak), is that the train actually goes through a tube UNDER the San Francisco bay.

That's the A-number-1 neurosis-inducing scenario, right there: that a major quake hits while the train is right in the middle of that tunnel. The tunnel's fairly well built seismically (it had no trouble in the 1989 quake that partly collapsed the Bay Bridge, for instance), but it needs a retrofit, because there is a risk that a really big one could liquefy the soil OVER the tunnel and the tunnel would start to buoyantly float up. Which would rupture it, and flood it. Game over for anyone in the tunnel at that point.

So that's my number one fear. And in order to engineeringly address that fear, I need to quantify how much of my actual life I spend in the tunnel.

My back-of-the-envelope calculation is that I spend 15 minutes per commute day in the deep tunnel itself under the water. I commute to work 3 days a week (I work at home 2 days a week, to avoid meetings -- we have good productive meetings at work, but still). Overall, the amount of my life I spend in the tunnel is 3/7 (commute days/days-in-week) times 0.25/24 or 1/96 (hours-in-tunnel / hours-in-day). Multiply that out very loosely, and you get something slightly under 0.5%. That's how much of my life I spend in the tunnel. (That's actually an upper bound, given sick days, vacations, et al.)

Therefore the chance that I will be in the tunnel when the Big One hits is really under 1 in 200. And knowing that, I actually rest a lot easier. There's still a major risk that I'll be on a train at 80 miles per hour when it hits, but at least if I survive the crash, I'll be able to climb out of the train without getting drowned!

Step 2: Prepare

Back to the list of scenarios. Neurosis minimization requires thinking through each of those scenarios and knowing what I'll do in each case.

If a quake happens at home or while I'm near home: my wife and I will rendezvous back home as soon as feasible. I have a 15 gallon water storage drum (that I need to change the water in, REMINDER TO SELF, CHANGE WATER) to handle the water going out, and we have a variety of canned and camping food, along with a camp stove. We also have LED flashlights and battery-powered radios, a non-cordless phone (cordless phones are useless bricks without power and the phone often comes back on before the power), and fire extinguishers / gas shutoff wrenches / etc. Oh yes, and we also have earthquake insurance. ($1,000 per year for increased worst-case peace-of-mind? That's a quake neurotic's bargain right there!)

So that's at home. During the commute, I make sure that I'm always wearing sufficiently warm clothing and practical footwear (sneakers, the engineer's all-purpose shoes) that if the train got crashed I'd be able to walk home without freezing or lacerating my feet. I look at all the women wearing open-toe shoes or sandals to work, and I shudder. After a major quake there's going to be broken glass and dangerous objects underfoot EVERYWHERE. Wearing sandals to work is just not a good idea in Northern California.

Also, I always carry a handy-dandy crank-rechargeable flashlight/radio in my backpack. Remember the BART tunnel nightmare scenario? If the power's out and the train is pitch black with people freaking out, I'm damn sure not going to be caught without some kind of light source. If I have to jog a couple of very adrenalin-packed miles through the tube to try to get out before it floods, being able to see where I'm going is Very Important. (REMINDER TO SELF: JOG MORE, STAY IN SHAPE.)

What about at work? There, I've got a basic under-the-desk quake kit that includes a hard hat, work gloves, power bars, a Camelback water pack, a sleeping bag, and a large backpack. Also, I always carry some spare cash in my wallet. If I survive the quake itself, I'll be better set up for the post-quake environment (which will be A Lot Different).

On the street in the city, I've become much more aware of vertical space. Walking by a multi-story old brick building, I'm often glancing up, thinking about the facade and about my escape strategy if a big one hits right then. One real problem about walking down the street is the uncertainty about shelter -- should you dart into a doorway? If you do, and the building comes down, uh-oh. Should you hide under a car? Probably not, because cars can bounce around and you don't wnat to be crushed by a tire. I often am aware of whether there's active traffic going by, in case I want to head for the middle of the street to get as far away from the buildings as possible. In general, sidewalks are one of the worst places to be, especially near tall buildings. Again, seeing women in high heel open-toe shoes on the sidewalk, while aesthetically pleasing (pardon my candor), is neurotically cringe-worthy.

Step 3: Blog

Having done all this, the other remaining step to clear my conscience is to tell other folks about it, so they can decide whether or not to have a similar level of neurosis :-) How much of this is rational, and now much is irrational? That's always subject to debate in any risk mitigation situation, but a lot of this is totally standard quake-preparedness advice. (The "flashlight in the tunnel" part, though, that's all mine :-)

Step 4: Relax

The final engineering response to this kind of neurosis is to chill out. Once you've done this kind of an assessment, and exhausted the reasonably practical responses, know that you've done mostly all you can and let it go! I sometimes tell people about this and they're like, "What the heck is up with you, man? You can't even walk down the sidewalk without freaking out?"

Well, honestly, I don't freak out. I'm just aware. Working all this out was stressful for a while, but now quakes are a background worry. I feel a whole lot better knowing exactly what I'll do when one hits than I would either ignoring the whole possibility or continually panicking about it.

Like I said: we humans aren't well suited for handling these kinds of generally-unlikely-but-ultimately-inevitable risks. We're all built-in neurotics around this stuff. So I've done the best I can. I hope you do, too, in whatever similar situation (hurricanes? fires? floods?) you might be facing yourself.

Next in the How To Be A Neurotic series: House Prices.