Not to impugn on your cred or anything, but 25 years may as well be the blink of an eye when you're talking about geological phenomenon.

> 'What are you worried about, I've lived here 25 years and that mountain never did shit.' -probably some Roman citizen in Pompeii, 79 BC

I too live in NorCal and am appalled by the glib headline on this NG article. We are encouraged to have emergency supplies ready in the event of catastrophe, the whole 'preppers are idiots' but a few aren't is really unhelpful and short sighted. I'm not a prepper and my emergency kit isn't in good shape but it should be...

Not the best example since there was a severe earthquake in Pompeii in 62 AD. They were still rebuilding in 79 AD when the town was destroyed by Vesuvius.

If they had taken the matter seriously, they'd not have rebuilt there. We know some Romans recognized the mountain as a volcano years before the eruption, but if there were any warnings associated with this recognition, they seem to have gone unheeded.

(Also, earth quakes are/were pretty common throughout Italy. This perhaps contributed to complacency.)

Lives are ~75 years long, should I actually invest any effort into large-scale problems that occur at scales longer than my life when there are risks that are far higher around which I can make direct changes?

Depends on how much effort it takes. Statistically, my house will never burn down within my lifetime, but the $20 it takes to buy a fire extinguisher is worth it. It also doesn't take much effort to do the types of things mentioned on https://www.ready.gov/kit

Likewise, I have all-electic heating and no gas service to my home, but a carbon monoxide detector only costs a few dollars so I still have one even though the risk is very low (most fires would probably trip the smoke detectors first I think.)

If it happens during your lifetime, it will likely only be once. So 'it never happened to me before' is not a very good way to reason about this sort of risk.

That's kind of an amusing way to put it: "Why would I prepare for a once-in-a-lifetime catastrophe? It never happened to me before."

Please recall that when the last "big one" happened in the Bay Area, the outcome was very few deaths (63 people died), but decades of economic problems. 500 people die in car accidents in the bay area every year. It would seem that fatalities from earthquakes aren't a good model for making rational decisions about what is likely to affect you in your lifetime.

You wear your seat belt, right? That's obviously a risk you already take seriously, so I'd not take it for a bound on tolerance for risk.

Cars pretty much define my bounds on tolerance for risk.

We also have a much better understanding of geological phenomenon and money likely gets you a faster evac than a gun and some gold bars. But again, pointless argument on my part since everything boils down to the point I made below.

> should I actually invest any effort into large-scale problems that occur at scales longer than my life when there are risks that are far higher around which I can make direct changes?

Yes.

The relevant number is not p, the likelihood of the event.

It is something like:

EV = p * consequences

If the consequences are high enough (eg, death), then it is still rational to prepare for low probability events. Especially when the prep cost is low.

... and what we've established is that not a lot of people die in big earthquakes, but there's a lot of economic impact. I think people overweight the consequences because earthquakes are big and exciting.

I suppose that's fair. But I think it's less the "big and exciting" part and more the "imagining myself trapped and dying of thirst" or some such that motivates the "consequences" part of the equation.

Where in northern California? If you're not near the coast, you probably will never experience an earthquake. As the recent quake in Massachusetts shows, however, earthquakes can happen almost anywhere.

Also, fun fact, the chances of a 'Cascadia megaquake', or a full rip of the Cascadia subduction zone, is about 1 in 6 over the next 50 years. That will produce a 9.0 extending from the Mendocino triple junction off the coast of Cape Mendocino, CA to Canada. It's the same type of earthquake that destroyed Fukushima. You'll have to be pretty far inland to avoid the shaking from that.

I find many times that scientists report ominious sounding things like this, but the underlying data doesn't support it. I think they're just prone to hyperbole and overselling their results because it's what brings in funding.

For anyone interested in the underlying data, I believe this is the most quoted piece by the popularizers:

https://pubs.er.usgs.gov/publication/pp1661F

...that has the full-fault events at ~500 year intervals, and the partial-fault events at ~240 year intervals. Last full fault event was January 26th, 1700.

You should look into the supporting data before making comments like this. The evidence for the timeline of past Cascadia zone megaquakes is actually quite solid. We can even corroborate the records from North American samples with samples from Japan when the resulting tsunamis caused damage there.

This is a good introduction if you want to know more: https://www.youtube.com/watch?v=UJ7Qc3bsxjI

For a software developer, 2 weeks worth of food isn't too bad on a budget, but could literally be a life saver in some situations, or even just soften the blow if I lost a job.

I live remotely and have no driving license. The reason i am prepping is the case when my partner (the one with the driving license) gets sick.

Its banal for a city dweller but necessary out here.

I can beat that. Here 45 years, same.

I do agree about your risk assessment. For water, those who have water heaters (rather than tankless systems) have a ready supply of drinkable water. Assuming that it isn't damaged/inaccessible after the earthquake. But, it is also possible a separate storage of water could be inaccessible after an earthquake.

We had a twenty year old water heater that finally called it quits this past spring. My wife and I discussed paying the extra cost to "upgrade" to a tankless water heater. In the end our frugal nature won and we put in another cheaper tank heater.

Then in August we were hit by a Derecho (an inland hurricane). The entire city was without power for more than 10 days (some much longer) and temperatures in the upper nineties. The one saving grace was I still had a working water heater since it's gas powered.

This is spot on for the entire prepping conversation - is the time worth the benefit given the likelyhood of event.

All other arguments for/against prepping derive from that.

Prepping is just insurance. I buy life insurance so my family is taken care of in the unlikely event that I die. I have some stored food, water, etc. in the unlikely event that there's a temporary disruption in my ability to get those things.

I wouldn't say dying is an unlikely event, even if you're young and healthy.

Insurance is you betting you will die and the insurance company betting you will not die. In order for the insurance company to make money, they have to be right more than you.