EARTHQUAKE Info: The Concord Fault & The Clayton-Marsh Creek Fault

August 28, 2014 8:00 am · 38 comments

Here is a little bit of information about the two local faults we have in Concord & Clayton, and provide a few important links.

We’ll start with the Concord Fault. Although it’s not a major fault, it’s an active one. A lot of people don’t know about the Concord Fault, which runs north through Concord to Suisun Bay. There was a damaging 5.4 magnitude quake in 1955, and the USGS says there’s a chance it could produce a 6.7 magnitude quake before the year 2030.

Another fault in our area is the Clayton-Marsh Creek Fault. This fault is also active and continues to elevate Mt.Diablo.

According to the USGS maps pictured above, it looks like the Concord fault goes from above Crystyl Ranch into Lime Ridge, over Ygnacio, continues through Lime Ridge, over Treat Boulevard, down to Systron Drive and San Miguel, then it runs right under the BART tracks near Systron Drive and San Miguel Road, apparently you can see several cracks in the pavement that were created by the activity on the fault. It then goes through Downtown Concord and on to Pacheco. The red dot that says “Concord” is about where Concord BART is located (see top photo).

As for the Clayton fault, it goes in between Seeno’s house on the hill and the Concord Pavilion, then into the hills where it goes in several different directions from there. You can click on the top picture for a larger view.

For information on how to prepare for an earthquake, click HERE, and for information on the chances of a major earthquake in our area in the next 22-years, then click HERE.

Jess August 28, 2014 at 8:14 AM

I seem to remember this same information from about 3 years ago. Are there any updates to the predictions?

Great information, Thank you Mayor August 28, 2014 at 8:18 AM

Preparation is vital, Food, water, medicine are all necessities we cannot live without.

Consider a CERT class.

Take some time to learn about being prepared and then do what works for you. Here is a suggested site;

Jess August 28, 2014 at 8:28 AM

Here’s an updated earthquake forecast map for the Bay Area that supersedes the 1999 forecast report.

For the faults in Claycord, probability of a 6.7 or higher in the next 30 years was forecast as 1% and 3% respectively.

Mamatosix August 28, 2014 at 8:41 AM

The truth is that an earthquake will happen and could happen at any moment.
We need to prepare our homes, offices and teach our children what to do.
And of course be completely prepared with supplies.

BagsFlyFree August 28, 2014 at 9:05 AM

Lets hope the CNWS planners work around that fault line on the base, and make that open/trail focused rather than stuffed with homes, gas lines and sewer mains.

julieindanaestates August 28, 2014 at 9:46 AM

They offer CERT (emergency preparedness classes) in our community;.it’s free, and can make a difference when there is any disaster…

RunnerDope August 28, 2014 at 9:47 AM

The Concord fault runs through the building I work in at Systron Donner. I’ll post from the abyss when it hits. 🙂

Antler August 28, 2014 at 9:49 AM

Excellent, Mayor! I have often wondered about what fault, named what, was where. I can see exactly where my property is.

Please, would you be able to take the map one more step so that we can see whether our earthquake faults are directly connected with the one in American Canyon/Napa Valley?

RunnerDope August 28, 2014 at 9:49 AM
Antler August 28, 2014 at 10:20 AM

So, Runner Dope…..someone once upon a time sat there and must have said, “I know what! Let’s build a major interstate highway and bridge right ON a known earthquake fault! Oh, and let’s put oil refineries there, too!”

And who went along with that? And why?

It makes ME feel angry. Anyone else?

And can anything be done about it at this point? Or do we just have to be stupid and stoic?

But who felt the Concord Quake? August 28, 2014 at 10:40 AM

This one happened a few hours before the recent Napa Quake and was centered in Claycord! Haven’t heard anyone talk about it but could this be the pre-cursor to “The Big One” along our very own fault line?

Smokey August 28, 2014 at 11:00 AM

I should be okay. I’m 5 or 6 miles from the fault.

rich August 28, 2014 at 11:24 AM

Google Earth has a quake fault link showing fault locations

@ Antler August 28, 2014 at 11:26 AM

Most of what you mention were built before there was access to all the scientific data about faults, types of soil, soil shifting etc. Places like Chevron and Shell were build prior to 1920….The highways and freeways follow old railroad lines. And don’t forget delta levees that were built in the late 1800’s early 1900’s. They are very old, very brittle and if the San Andreas or Haywards faults go they too could be compromised.

Scientist are finding new faults all the time. Loma Prieta an unkown fault when it went. So Antler things are not as easy peasy as you think.

Tal August 28, 2014 at 11:58 AM

Don’t forget the Mt. Diablo thrust fault. Look that one up…

@11 August 28, 2014 at 12:35 PM

No one feels a quake that small,,, those happen all the time, and are never precursors

slagheap August 28, 2014 at 1:01 PM

at our place here in north concord we were awakened to a full 20 to 30 seconds of violent shaking – still can’t believe we escaped ( apparently, ) with no damage. i’m glad i strapped down the water heater.

Always Right August 28, 2014 at 1:41 PM

Well I guess I can’t blame this on the Democrats.

For once it is not their fault.

Antler August 28, 2014 at 2:20 PM

#14…. A very long, relatively narrow valley going up between two significant lines of mountains? Earthquakes experienced in the past history of this area?

Your reasoning is about like saying that people on the East Coast were not aware of hurricanes and resultant damage before airplanes started flying into the eyes of the storms.

@Antler August 28, 2014 at 3:45 PM

Yeah,, and why didn’t we just move San Francisco east after 1906… Are you the type that dosen’t leave his house cause something bad “might” happen?

@ Antler August 28, 2014 at 4:07 PM

People are sick of you being a”know it all…….Bottom line the science was there when refineries and other thing were built. So you have a PhD in Geology dating from 1880?? (we know you are old enough) Please tell all of us about tectonics., liquafaction an components of geologic science since you are such an expert.
The last time the Hayward fault had a major move (was around 6.8) was 1868. You do realize a chunk of the Cal Campus is also on the Hayward Fault don’t you?????? There are also severl other schools, hospitals and public complexes that sit on the fault. There is a huge visible crack on the hill behind Cal State Hayward that is actually part of the fault. Did you, almighty Antler know that??? I bet not.
Good one #20. I couldn’t agree with you more.

@ Antler August 28, 2014 at 4:11 PM

Edit….should read: “science was NOT there when refineries and other things were built”.
Should read: “liquafaction and other components of geologic science”
Should read: “There are several other schools, hospitals…”

Hard to type with the Almight Antler spouts off her crap.

@@Antler August 28, 2014 at 5:46 PM

Be careful, you may get her life story in her defense. Then you’ll really be in for it….

WTF August 28, 2014 at 5:58 PM

Wine bottles, corkscrew pull & plastic wine glasses all together. Okay earth, you can quake now ⊙.○

Trailer Chick August 28, 2014 at 7:00 PM

Thanks for the detailed info, Mayor. We live atop the Concord fault (at San Miguel and Systron) and whenever there’s shaking in the area we feel it. It was my first suspected cause of that BART train derailment awhile back. I had no idea, however, that it had the potential for a big one. Appreciate the heads up.

The Realist August 28, 2014 at 10:12 PM

Why does everyone always forget ammo, yes can food, bottled water and essential prescription medication are important. But when landlines and cell tower are unavailable, its not the 80 year retired neighbors you have to worry about taking your supplies. It’s the violent parolee who got mandatory released because of overcrowding. Thanks moonbeam
Just remember, when seconds count in a catastrophe, the police will be no where to be found.

@ #23 August 28, 2014 at 10:33 PM

Perhaps we will get lucky and Antler will discover her house sits on a fault and she will move it far far away……………Like Siberia

Sgt. Turdy August 28, 2014 at 11:03 PM

@ Realist – Everybody already hoarded all the ammo. I don’t really believe there is such a thing as “too much ammo”, but is there anyone out there who doesn’t have at least 500 rounds?

Elwood August 28, 2014 at 11:26 PM

It’s Bush’s fault!

Dr. Jellyfinger® August 28, 2014 at 11:32 PM

I didn’t even feel that last quake…. of course I was making love to an inebriated Hula Dancer on top of the washing machine on “spin cycle” at the time… and the load was off balance!

Antler August 29, 2014 at 2:36 AM

To the @ troll who claims to speak for “the people on here”.

Your comments at #21 actually corroborate the point I made, which was that the science was already here but was ignored. You forgot to mention the nuclear plants, Livermore Lab, so many more, which of course I know about just like everyone else knows. But was this discussion about all those other places on all those other earthquake faults?….NO. That was your own idea.

And deciding to hate and to be rude to me was also your idea. Did you also pile on more posts pretending to be other people? Are you the same barefooted hero troll I called out for writing the nebulous mailbox theft piece? Same lack of integrity then and same enraged rant is showing up in your personal attack here. Sloppy technique back then, too, by the way. Please try to tighten up your plots….cross-check details to support one another….and don’t forget to smell the roses.

And I still deplore the fact that a major interstate and bridge (punctuated by oil refineries)….. a major evacuation route……. traces an earthquake fault.

To sum things up August 29, 2014 at 9:14 AM

people who judge decisions made by people in the distant past by today’s advanced standards are simply showing off their arrogance and ignorance.

Antler August 29, 2014 at 10:43 AM

#32, Please remember that snide remark when you read about the latest attempts to locate Lawrence Livermore to the unstable Berkeley flatlands next to SF Bay.

Meanwhile, has anyone heard about an inspection of the roadbed south of the Benicia Bridge (George Miller, Sr. Bridge) in the area where there were previous skate-board park types of waves in said roadbed?

Teacher Wannabe August 29, 2014 at 11:04 AM

And the Hayward fault (which is long overdue) runs right where 13 goes from 24 to 580. That little valley it runs rhough? That’s the fault. Another great idea. Right along with Mission Valley/ Fashion valley shopping centers in San Diego. The river floods every heavy rain. Who builds houses and retail in a river bed?

Kirkwood August 29, 2014 at 11:58 AM

Hang in there Antler, you have friends here also. The topic is not worth arguing. (the Mayor might disagree) ;-).

The Realist August 29, 2014 at 3:35 PM

Wow, people actually hoard over 500 rounds? I thought that gets you flagged by the DOJ as a domestic terrorist.
I feel bad now for only having 250 rounds for the handgun and 200 for the shotgun.
I’m going to shop around for a carbine. Seems I have some catching up to do.

@ Antler August 29, 2014 at 8:41 PM

Don’t flatter yourself………I don’t hate you because you are worth zero effort. Just another lonely old lady with no life and completely boring.
And no, science in a sophisticated form wasn’t available.. Most progress with faults and quakes stated during the 1970’s. And get this Almighty Antler they are finding new faults all the time…………….it is not an exact science…Oh wait you know better than any geologist . One can only pray you are standing on a fault when it goes so you are sucked up.

Antler August 29, 2014 at 9:44 PM

Kirkwood, thank you for recognizing my points and for posting kind words.

One more attempt to activate Little Troll’s one brain cell:

Engineers knew about earthquakes and fault lines “way back then”….just by looking at the topography. They know even MORE about the problems now. Yet they still are making the SAME foolish projections about where to put application-sensitive and population-sensitive installations.

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