Earthquakes in SF vs. elsewhere

When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

wrote in message
oups.com...
When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

Of course (and, in fact, they have as recently as 1994). The San Andreas
fault runs up the coast of most of California. Additionally, the entire
west coast is on the subduction zone of the Pacific tectonic plate. There
have been major earthquakes from Alaska to Mexico.

wrote:

When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

The next REALLY BIG quake could be along the New Madrid Fault which
basically runs from near St. Louis to Chicago. California is "Somewhat"
prepared for a quake - St. Louis, Kansas City and Chicago are NOT.

wrote:

When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

The San Andreas Fault is a major fault line that has a history of a huge
quake (magnitude 8) on the average every 140 years. The last one in San
Francisco was a magnitude 7.1. It caused massive damage and there were a
lot of people killed, but that would pale in comparison to a magnitude 8
quake. San Francisco is quite a bit closer to the fault line than Los
Angeles.

On 11 Sep 2005 16:28:01 -0700, wrote:

When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

SF is not on a fault, but it is quite close to the San Andreas
Fault. LA is quite far from the San Andreas Fault, and a quake on
the SAF at its closest point to LA will not be as bad as a quake
on the SAF at its closest point to SF. SF is also less than ten
or so miles from the Hayward Fault, whihc is the one expected to
be the source of the next Pretty Damn Big One.

On the other hand the LA metro area is riven with a plenitude of
lesser faults, including a number of "hidden" faults.

************* DAVE HATUNEN ) *************
* Tucson Arizona, out where the cacti grow *
* My typos & mispellings are intentional copyright traps *

Hatunen wrote:


1994 wasn't a huge earthquake.


I guess "huge" is a relative term. The Northridge ('94) quake was a
6.7, and was really scary to live through. We were 25 miles or so from
the epicenter and so were relatively unscathed, but there was massive
property damage (I had friends who lost their homes) and some loss of
life as well. Now I live near Seattle. We had a 6.8 quake here in
2001, but it wasn't nearly as frightening, or damaging, as the
Northridge quake (mostly because it was centered far underground.)

On Sun, 11 Sep 2005 23:51:07 GMT, "PTravel"
wrote:


wrote in message
roups.com...
When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

Of course (and, in fact, they have as recently as 1994).

1994 wasn't a huge earthquake.


************* DAVE HATUNEN ) *************
* Tucson Arizona, out where the cacti grow *
* My typos & mispellings are intentional copyright traps *

"Hatunen" wrote in message
...
On 11 Sep 2005 16:28:01 -0700, wrote:

When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

SF is not on a fault, but it is quite close to the San Andreas
Fault. LA is quite far from the San Andreas Fault, and a quake on
the SAF at its closest point to LA will not be as bad as a quake
on the SAF at its closest point to SF. SF is also less than ten
or so miles from the Hayward Fault, whihc is the one expected to
be the source of the next Pretty Damn Big One.

On the other hand the LA metro area is riven with a plenitude of
lesser faults, including a number of "hidden" faults.


For SF Bay area cities and earthquake shaking intensity.
http://www.abag.ca.gov/bayarea/eqmaps/pickcity.html

"Hatunen" wrote in message
...
On Sun, 11 Sep 2005 23:51:07 GMT, "PTravel"
wrote:


wrote in message
roups.com...
When people talk about the next big quake, why do they always talk
about SF and not LA? SF is right on a fault, I know, but then they had
a big quake in 1994 in LA. Couldn't there theoretically be a huge one
in LA?

Of course (and, in fact, they have as recently as 1994).

1994 wasn't a huge earthquake.

It depends on how you define huge. I was 6 miles from the epicenter. My
house survived (with large cracks in the wall and nothing inside left
standing). Others in my neighborhood weren't as lucky -- their buildings
collapsed and/or burned.



************* DAVE HATUNEN ) *************
* Tucson Arizona, out where the cacti grow *
* My typos & mispellings are intentional copyright traps *

wrote:
When people talk about the next big quake, why do they always talk
about SF and not LA?

Because we've actually had a Great 'Quake! Los Angeles has not. For the
reasons Hatunen says, it is not likely to.

Hatunen wrote:
SF is not on a fault, but it is quite close to the San Andreas
Fault. LA is quite far from the San Andreas Fault, and a quake on
the SAF at its closest point to LA will not be as bad as a quake
on the SAF at its closest point to SF. SF is also less than ten
or so miles from the Hayward Fault, whihc is the one expected to
be the source of the next Pretty Damn Big One.

SF is right on a fault, I know, but then they had a big quake in
1994 in LA. Couldn't there theoretically be a huge one in LA?

Although it's correct to say that we don't sit on the San Andreas Fault,
it misses us by only a mile or so where it comes inland to pass through
Daly City. I sit fewer than three linear miles from the fault. No part
of San Francisco's contiguous land is farther than eight miles from it.


PTravel wrote:
wrote:
Couldn't there theoretically be a huge one in LA?

Of course (and, in fact, they have as recently as 1994). The San
Andreas fault runs up the coast of most of California.

No, it doesn't (well it does North of Daly City). It comes in just below
the City Limits and goes farther inland where it remains for about five
hundred miles to beyond Palm Springs. I believe, but do not know, that
everything West of the fault is on the Pacific Plate (San Luís Obispo,
Santa Barbara, Los Angeles, Palm Springs) and everything East of it is
on the North American plate (San Francisco, San José, Fresno,
Bakersfield [where a 'quake stronger than Loma Prieta or Northridge hit
in 1952]).

On September 4, in another Group, I said:
Hatunen wrote:
I have serious doubts about San Francisco's (and the Bay Area's)
survivability after another 1906, despite the constantly upgraded
building codes, especially after 1957.

That's the one that terrified me and made me profoundly understand
our insignificance to Mother Nature. We are no more noticed by her
than the ants we kill as we walk down the street.

Loma Prieta was nothing, a mere blip in comparison to another 1906

Unquestionable.

On the same date, about Hurricane Katrina, I said:
My disgust has turned to anger and, in a not quite abstract way, fear
as, at any instant, San Francisco or Seattle or Anchorage or Los Angeles
or New Madrid could be hit with a Great 'Quake.

And on September 5 I said:
Hatunen wrote:
How many big earthquakes have you see? Did you see the footage of
tghe big earthquke in Turkey.

I forget the intensity, but I believe it was around 6. Fourteen thousand
people died. Similar intensity 'quakes here result in few to no deaths
and very little damage, mostly stuff knocked offa shelves.

I believe the difference is the enforcement of building codes. Turkey's
are similar to California's but the enforcement isn't (well, it wasn't).

I've been through many 'Quakes; the one that terrified me in '57, the
one that cost me money in '89, and many others. I'm resigned to the
probability that I'll get killed when another 8 comes our way. After
Loma Prieta, I've come to believe that nothing, no matter what's done,
can stand up to a Great 'Quake. The damage, in lives and money, that
will happen here will greatly exceed New Orleans. A hundred thousand
dead, five times as many injured (and 20% of them die later from their
injuries), devastated infrastructure, and half a million homes gone in
the counties of San Francisco, San Mateo, Alameda, Marín, Santa Clara,
Contra Costa, Sonoma, Napa, and Solano.

As for tsunami, most of the 30,000,000 or so people in California
don't live close enough to the ocean to care, r live high enough for
it not to matter.

I don't know the elevation of my home, but it has to close to 150 feet.
The ocean has a relatively straight shot to get here but I doubt that
it'd get here.

How many floods have you personally witnessed?

I witnessed the aftermath of a flood in Jackson, Mississippi, but it
wasn't serious. I was once in Napa when the river's was perhaps three
feet below street level. On another occasion, I saw that river at what
is probably its normal level, about thirty feet below street level.
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