
When, not if: how do San Franciscans live with the threat of the next quake? - yread
http://www.theguardian.com/cities/2014/mar/27/san-francisco-live-constant-risk-next-major-quake
======
chrisfarms

        "Between now and 2038, there’s a 99.7% chance of a
        6.7-or-larger earthquake striking somewhere in 
        California"
    

I can't see that date without thinking a 32bit timestamp prevented them from
calculating over a larger range. :)

~~~
ekianjo
6-7 is not THAT bad. Most modern buildings should be able to handle this
relatively fine. In Japan usually nothing recent falls apart until after 7.
Anyway, in terms of casualties, it all depends where the epicenter exactly is,
and at what time of the day or night the earthquake strikes.

~~~
eloisant
I actually believe the construction in Japan are much more reliable than
construction in San Francisco.

The earthquake risk is everywhere in Japan, so that's a major point that all
construction rules take into account. Those rules are revised regularly,
getting stricter as technology permits it. A good chunk of the property owners
fees go into renovation to make the building earthquake-safe, and an building
decreases in value as it gets older because people know it won't be as strong
in case of an earthquake.

On the other hand earthquake is not a problem in most places in US, even
California doesn't compare to Japan in terms of earthquake risks - outside the
Bay Area. So the whole country isn't thinking in terms of earthquake
protection, and that makes a difference.

So San Francisco will certainly do much better than Turkey or Haiti, but I
don't think it will resist as well as Tokyo.

~~~
ekianjo
> The earthquake risk is everywhere in Japan,

Not completely true. There's a risk map established by the government in Japan
and several areas are considered "safe". For example, Kyoto has not had major
earthquakes for centuries.

> A good chunk of the property owners fees go into renovation to make the
> building earthquake-safe

That's not true either. Usually buildings have a "shelf life" in Japan and
whenever they reach the end they end up being destroyed and replaced by newer
ones (built with the latest standards). Besides, older constructions can be
actually pretty solid, it's rather all the newer stuff with large window panes
and less walls that tend to be more fragile.

~~~
seanmcdirmid
Kobe is right next to Kyoto and recently had a major earthquake (1995?).

A lot of the older Japanese construction, especially out of Tokyo, is poorly
insulated and kind of flimsy. I was very surprised since I always thought of
Japan as being rich. I'm sure the wood would do well in the earthquake, but
that's the other problem: wood eventually rots and needs to be replaced (those
Shinto temples are rebuilt every 30 or 40 years I think).

~~~
ekianjo
> Kobe is right next to Kyoto and recently had a major earthquake (1995?).

Hey man, I live in Kobe :) Kyoto was left largely intact after the earthquake
in 1995. Of course they felt it, but nothing was devastated there. Kyoto is
further up in the middle of the land, further from the seismic rifts, and
relatively safe in terms of location.

> (those Shinto temples are rebuilt every 30 or 40 years I think

I think you are refering to Ise Jingu which is destroyed and entirely rebuilt
every 20 years. But that's a very different thing. Most large temples no not
get rebuilt very often, and their trunks can last centuries.

------
raldi
The problem is that earthquake insurance is so expensive and so high-
deductible that a risk analysis only concludes it's worth getting if you live
in an especially risky neighborhood, or have an especially at-risk house.

So only the riskiest buildings get it.

So the average customer of the insurer skews ever closer towards the extremely
at-risk end of the spectrum.

So the insurance companies have to raise the rates and deductibles.

And then you go back to step one, and the vicious cycle gets even more
extreme.

~~~
thaumasiotes
> So only the riskiest buildings get it.

> So the average customer of the insurer skews ever closer towards the
> extremely at-risk end of the spectrum.

> So the insurance companies have to raise the rates and deductibles.

This chain of "logic" only makes any sense if you assume that the insurance
companies have to offer all their customers the same rates and deductibles. If
the building owners can figure out that they're facing an elevated risk, why
can't the insurance companies?

~~~
raldi
They're mandated by California law to insure anyone who wants it.

~~~
thaumasiotes
That doesn't address anything I said. My parent comment already presupposed
that they're able to change their rates. Are they really required to insure
anyone who wants it, all on exactly the same terms? If so, maybe the problem
isn't that earthquake insurance is just a natural death spiral?

~~~
raldi
_> all on exactly the same terms_

It's not that simple, but it _is_ that heavily-regulated:

[http://law.onecle.com/california/insurance/10089.html](http://law.onecle.com/california/insurance/10089.html)

------
steven2012
Actual former SF resident here. I'll tell you exactly why I would live in SF,
it's because it's one of the most beautiful cities in the world, and I also
choose not to live my life in fear.

Yes, there's a threat of earthquakes. Yes, I'm sure there is going to be an
earthquake at some point, possibly even large. I experienced a tiny earthquake
in SF a few years ago and it scared the shit out of me, because my entire
apartment was shaking.

But there are threats everywhere. Would I buy a house (if I can afford one,
that is) in a liquefaction area? No. But there are plenty of areas of SF that
don't have imminent liquefaction risk. And the chance of actually dying is
quite low. There are plenty of things to worry about, but earthquake would be
on the bottom quartile for me. And compared to the benefits of living in SF,
it isn't even a big concern.

------
_stephan
If you don't buy earthquake insurance, can you count on state or federal
disaster relief programs to pay for reconstruction?

[Edit] Or to rephrase the question, do disaster relief programs create a moral
hazard that should be countered by making earthquake insurance in high-risk
areas mandatory (with possible subsidies by the state)?

~~~
blaze33
The wikipedia page of the 1906 earthquake[1] is quite instructive:

> Capt. Leonard D. Wildman of the U.S. Army Signal Corps reported that he "was
> stopped by a fireman who told me that people in that neighborhood were
> firing their houses…they were told that they would not get their insurance
> on buildings damaged by the earthquake unless they were damaged by fire".

[1]
[http://en.wikipedia.org/wiki/1906_San_Francisco_earthquake#S...](http://en.wikipedia.org/wiki/1906_San_Francisco_earthquake#Subsequent_fires)

~~~
Spooky23
The issue wasn't that simple. The Army marched in and pretty much went rogue
-- they came in and started blowing up buildings to create firebreaks and
caused more fires in the process.

The city was also particularly vulnerable to destruction from fire. Lots of
unstable landfill, the water used for fire fighting was in underground
cisterns that were damaged, and key firefighting personnel were killed.

There's a recent book "San Francisco is Burning" that is a really good
account.

------
danieltillett
I always thought it was the classic human response to disaster planning - a
large river in North Africa.

~~~
panacea
The human response to disaster planning is offloaded to a committee who's
responsible for disaster mitigation.

Call it a government.

Residents living on the banks of that large river in North Africa built a
fucking awesome risk mitigation strategy for said government. Eternal life
under a stacked pyramid of stones.

------
jofer
What's interesting is that everyone's very aware of the seismic hazard along
the San Andreas, but many people aren't aware of the much larger (but much
less frequent) hazard in the Seattle/Portland area.

The San Andreas is a strike-slip system. It's not capable of generating very
large (magnitude 8 or greater) earthquakes.

The Cascadia subduction zone has had magnitude 9 earthquakes in the past. The
last one was on Jan. 26th, 1700. (Thank Japan for having excellent historical
records of earthquakes and tsunamis. We know a large earthquake occurred
around 300 years ago in the area, and thanks to Japan's record of the tsunami
it caused, we can make a solid link to the exact date.)

We don't know the statistical hazard as well due to the small sample size, but
when the next large Cascadia earthquake occurs the damage will be absolutely
catastrophic.

It's not just the direct earthquake damage, but also the tsunami hazard. You
need vertical offset to cause a tsunami. A strike-slip system like the San
Andreas is very unlikely to cause a tsunami. The permanent offset is
dominantly horizontal, so the only way to generate a tsunami is through
secondary effects such as landslides. (Also, most of the length of the San
Andreas is onshore.)

Subduction zones are thrust systems. One plate moves up, and the other moves
down. Earthquakes there are likely to produce permanent vertical deformation
at the surface.

Furthermore, certain types of subduction zones are more prone to generating
large tsunamis. A deep earthquake is unlikely to cause much deformation at the
seafloor, and therefore doesn't generate as large of a tsunami. However, the
shallower the rupture penetrates, the larger the deformation at the seafloor
is, and therefore the larger the tsunami is. Certain types of subduction zones
are more prone to having large earthquakes that rupture all the way up to the
seafloor. (The amount of sediment on top of the incoming oceanic plate is
thought to play a large role in this, among other things. The recent Tonankai
earthquake in northern Japan turned a lot of what we thought we knew about
this on its head, though.)

The Cascadia subduction zone is one of the end-member types that's likely to
have both large earthquakes and large tsunamis. We know it has in the past,
and it's likely to in the future. It's unusual in that most of the deformation
along the fault occurs through periodic creep ("slow-slip events") that
doesn't cause an earthquake. (Actually, as we're finding out, it's not that
unusual around the world, but it was first observed and is best documented in
Cascadia.) However, while this creep does relieve a significant portion of the
accumulated elastic strain, it doesn't relieve all of it. The plate boundary
fault is still accumulating elastic strain that will eventually be released in
a large earthquake.

At any rate, just something to think about. The seismic hazard in the Bay Area
can be reduced through proper engineering solutions. (Though SOMA is going to
be in very rough shape for the reasons this article mentions. Lesson for next
time: Don't bulldoze all the rubble into a pile and then build on top of it!)

For Cascadia, though, you can't engineer your way around a magnitude 9
earthquake and tsunami. You do the best you can, and try to avoid putting
critical infrastructure near the coast.

~~~
jchrisa
Portland is starting to wake up to the issue. This was a fun event we have, to
encourage people to be prepared to help.
[http://bikeportland.org/2013/07/13/disaster-relief-trials-
br...](http://bikeportland.org/2013/07/13/disaster-relief-trials-
bring-30-miles-of-urban-apocalyptica-back-to-portland-90373)

Not sure what to say about all those houses in the west hills besides good
luck...

~~~
ianvanness
The Portland Mercury (a free alt-weekly) published a cover on this last year,
mostly about how ill-prepared the city is in general for earthquakes. Glad to
see this sort of friendly-neighbor approach happening though, as it's going to
be more effective right now than waiting for the politics to catch up, and oh
so very Portland.

[http://www.portlandmercury.com/portland/the-first-four-
minut...](http://www.portlandmercury.com/portland/the-first-four-
minutes/Content?oid=5766214)

------
discardorama
Don't look at it as an "earthquake", look at it as a buying opportunity! ;-D

~~~
aylons
Actually, if most buildings get destroyed without insurance, prices will rise
as offer shrinks.

Unless you're trying to buy terrains for construction.

------
hindsightbias
It's up to the landlords. Soft-Story retrofits are the law now.

[http://www.sfgsa.org/index.aspx?page=6048](http://www.sfgsa.org/index.aspx?page=6048)

"On the anniversary of the 1906 San Francisco Earthquake, Mayor Ed Lee signed
into law the Mandatory Soft Story Retrofit Ordinance. This legislation
requires the evaluation and retrofit for “multi-unit soft-story buildings,”
defined as: Wood-frame structures, containing five or more residential units,
having two or more stories over a "soft" or "weak" story, and permitted for
construction prior to January 1, 1978."

------
cylinder
I can't believe only 10% of SF homeowners have earthquake insurance.

Unfortunately, I'm sure there will be a taxpayer funded bailout of all these
people once their homes are damaged/destroyed in the next big one. So, why
bother?

------
jfb
"Whistling past the graveyard". There's good stuff in John McPhee's
_Assembling California_ [1] about the '89 Loma Prieta earthquake, and about
earthquakes in general.

[1] [http://www.nytimes.com/books/98/07/05/specials/mcphee-
califo...](http://www.nytimes.com/books/98/07/05/specials/mcphee-
california.html)

------
facepalm
I wonder, could it make sense to build houses in risky areas more like ships?

~~~
danieltillett
What is required to make a building survive a big quake has been known for
some time - the real question is has it been done on the building you are in
when the next big quake hits.

~~~
dredmorbius
And more specifically (concerning regional resilience): how much of the
existing housing stock is built to standards which will survive a likely
quake?

San Francisco's last slate-cleaning came in 1906, though parts of the city
were constructed far more recently. The 1989 earthquake (nearly 100 km distant
and comparatively mild (6.9, as opposed to an 8 or 9 mag such as the 1906
quake) still caused significant structural damage throughout San Francisco,
though major damage was limited to a few neighborhoods and specific buildings
-- more major damage was concentrated largely to the south, closer to the
epicenter.

Most of Tokyo was destroyed during WWII, and has been rebuilt since. Japan
also experiences frequent powerful earthquakes (several M8+ quakes are noted
by the USGS:
[http://earthquake.usgs.gov/earthquakes/world/historical_coun...](http://earthquake.usgs.gov/earthquakes/world/historical_country.php#japan)),
effectively requiring more robust building standards. Though my understanding
is that there's a great deal of collaboration between Japanese and Californian
engineers on this work.

~~~
domdip
1906 was somewhere between 7.8 and 8.25. Pretty far from 9. "8 or 9" is a huge
range at that scale.

~~~
dredmorbius
Right. Loma Prieta was pretty serious, particularly closer to the epicenter
(and as I recall, damage sort of hopped and skipped among geologically
unstable landforms for quite some distance). But it was less than 1/10th as
powerful as the 1906 quake.

And yes, M9s are monsters -- the Boxing Day and March 11 earthquakes in
Indonesia and Japan were both M9s, I believe there was one in Chile ... ok,
that was 1960 -- the 1964 Prince William Sound, Alaska, quake was also 9+.
Listing at Wikipedia:
[https://en.wikipedia.org/wiki/List_of_earthquakes](https://en.wikipedia.org/wiki/List_of_earthquakes)

On the US West Coast, it's the Oregon / Washington coast which would be most
likely to see a quake of that magnitude, along the Cascadia fault, a
megathrust fault which could produce similarly large tsunamis as well as
massive shaking. For most of California, not so much.

------
hspain
Californians especially are woefully unprepared for disaster. I started a
local company ([http://expresssurvival.com](http://expresssurvival.com))
selling survival kits and emergency gear to try to help the community get
prepared and realize the importance of having those supplies when that next
earthquake hits.

Most of us understand that its not a matter of if, but when we will need those
emergency supplies, but as someone pointed out earlier, we are "whistling past
the graveyard."

------
sssbc
So lets disrupt a bit: 1\. Identify companies with liquidity, significant
exposure to earthquake damage (down to the liquification zone offices) 2\.
short their stock 3\. Wait for the 99.7% chance of earthquake by 2038 (more
math to follow) 4\. profit! Warren Buffet might be interested, since he's
taken up betting against idiots. YC application, here I come!

------
cordite
The same story applies to Utah Valley, we are 60 years overdue

~~~
marknadal
One of the biggest reasons I have avoided moving to SF is because of
earthquake liquefaction dangers. I however just recently moved out to Provo
Utah from LA temporarily - I didn't know this was a hotbed as well. How would
you compare the threat levels here to SF? Comparable? Or severely less than
SF?

~~~
matrix
The risk is lower, but still high. The last estimate was a 16.5% chance of a
magnitude 7.0 earthquake in 100 years[1]. I expect the probability will be
revised to be higher in the seismic hazard assessments due to be released this
year.

7.0 doesn't sound big, but keep in mind, the epicenter would be quite close to
the surface and likely to be right in the middle of a highly populated area on
the Wasatch Front (Salt Lake City, Cottonwood Heights, etc). Also, many
buildings in the vulnerable areas pre-date construction codes that take
seismic risk into account. For example, it wasn't until the late 70's that
they started reinforcing masonry construction.

[1] [http://www.livescience.com/28782-utah-bigger-earthquakes-
was...](http://www.livescience.com/28782-utah-bigger-earthquakes-wasatch-
fault.html)

