Hayward fault "locked and loaded" for 6.7-7.0 earthquake

[irishgrl]

Fault East of Bay Area 'Locked and Loaded'

By SCOTT LINDLAW, Associated Press Writer 1 hour, 32 minutes ago

HAYWARD, Calif. - New cracks appear in Elke DeMuynck's ceiling every few weeks, zigzagging across her living room, creeping toward the fireplace, veering down the wall. Month after month, year after year, she patches, paints and waits.

"It definitely lets you know your house is constantly shifting," DeMuynck said. So do the gate outside that swings uselessly 2 1/2 inches from its latch, the strange bulges in the street and the geology students who make pilgrimages to her cul-de-sac.

DeMuynck could throw her paint brush from her front stoop and hit the Hayward Fault, which geologists consider the most dangerous in the San Francisco Bay Area, if not the nation. Like others who live here, she gets by on a blend of denial, hope and humor.

It's the geologists, emergency planners and historians who seem to do most of the worrying, even in this year of heightened earthquake awareness for the 100th anniversary of San Francisco's Great Quake of April 18, 1906.

Several faults lurk beneath this region, including the San Andreas Fault on the west side of the Bay area, but geologists say the parallel Hayward on the Bay's east side is the most likely to snap next.

"It is locked and loaded and ready to fire at any time," said
U.S. Geological Survey seismologist Tom Brocher.

The Hayward Fault runs through one of the country's most densely populated areas; experts say 2 million people live close enough to be strongly shaken by a big quake.

It slices the earth's crust along a 50-mile swath of suburbia east of San Francisco, from exclusive hilltop manors overlooking the bay to Hayward's humble flatlands. It snakes beneath highway bridges, strip malls, nursing facilities and retirement centers, and it splits the uprights of the football stadium at the University of California, Berkeley.

"A lot of these structures are going to come down," said David P. Schwartz, chief of the USGS's Bay Area Earthquake Hazards Project. He spoke with one foot on either side of the fault, marked by a crack that snaked through a parking lot in Hayward's business district.

Before San Francisco's Great Quake of 1906, on the San Andreas fault, there was the Great Quake of 1868 on the Hayward, a magnitude 6.9 rumbler that killed five people. Severe quakes have happened on the Hayward Fault every 151 years, give or take 23 years, meaning it is now into the danger zone.

Experts forecast the next big one will be in the potentially lethal 6.7 to 7.0 range. The Association of Bay Area Governments estimates it would wipe out some 155,000 housing units, 37,000 in San Francisco alone.

The ground on each side of the fault could shift 3 feet, meaning two objects on opposite sides could be abruptly carried a total of 6 feet apart, Schwartz said.

The Hayward Fault runs directly beneath Eden Jewelry and Loan, but the men working in the pawn shop shrugged when asked if they fear a quake.

"Honestly, it's a non-issue," said Saul Gevertz, 64.

The building was renovated about five years ago and now is essentially an enormous steel cage, designed to flex in an earthquake without breaking, said one of the building's co-owners, Darrell Davidson.

"I'm not worried-worried. I've thought about it," said Davidson, 47. "I think we're in good shape. I hope to God we are."

Nickey Avila acknowledged some alarm when informed that the fractures in the pavement outside his house were caused by the fault.

"I'm thinking one day it's going to move, but if I survive it, I'll be able to say I survived one of the biggest quakes of all time," said Avila, 23.

The quake could come at any moment.

"If it moved while we were walking, it wouldn't surprise me," Schwartz said during a tour of Hayward's misaligned street curbs, warped concrete gutters and abandoned buildings. They include the former Hayward City Hall, deemed too dangerous to occupy because it's right on the fault.

The City Hall was built in 1930, during an unusually quake-free period after the Great Quake of 1906 released stress on all faults in the region.

A "virtual tour" developed by the USGS shows the Hayward Fault slashing through identifiable structures, like DeMuynck's house, but she is resolved not to worry.

"There's dangers all around us, all the time, so if we thought about those dangers all the time, we wouldn't have anything else to think about," said DeMuynck, 62. "We just come home and say, 'The house is still here.' We're OK for another day."

go here (http://quake.wr.usgs.gov/research/seismology/wg02/media.html)for actual USGS graphics used to make predictions....

[Richard B]

"There's dangers all around us, all the time, so if we thought about those dangers all the time, we wouldn't have anything else to think about," said DeMuynck, 62. "We just come home and say, 'The house is still here.' We're OK for another day."
I love this guy's comment. Perfect.

You do realize that this article has been written time and time again starting around 1979.

[amber]

I love this guy's comment. Perfect.

You do realize that this article has been written time and time again starting around 1979.

do you realize the fault line is under my crappy old house?!



:laugh:

No, really though. I freak out pretty much every day.

[DavidMn]

It's like youre damned if you do, damned if you dont.

[Richard B]

do you realize the fault line is under my crappy old house?!



:laugh:

No, really though. I freak out pretty much every day.
That is freaky. Why would a contractor build directly on a fault line? Must be a old home.

Growing up, we had friends in the East Bay and their house was on a fault line. As you know, the two plates move every so slowly, so after awhile there was literally a crack from one end of the home to the other as a result from the plates moving. Obviously this is very gradual but eventually the house had to be torn down, family fully refunded and relocated of course.

[irishgrl]

I love this guy's comment. Perfect.

You do realize that this article has been written time and time again starting around 1979.

apparently you didnt read carefully enough:
Severe quakes have happened on the Hayward Fault every 151 years, give or take 23 years, meaning it is now into the danger zone. (The last Great Quake of 1868 on the Hayward, a magnitude 6.9 rumbler killed five people)

in other words, this is a regular occurrence, kinda like a tectonic OLD FAITHFUL...and people have notoriously short memories....as for the "what me worry?" comment, I read the exact same comment from an Italian who lives on the slope of Vesuvius. and that old Geezer who refused to get off of Mt. Saint Helens when it blew........people who say stuff like that are in severe denial and have no one but themselves to blame when disaster hits.

btw: developers will build in floodplains, quake zones, lava paths, forested areas.....the point is, they dont give a damn about the risks involved. They are banking on the blase attitude of buyers. Kinda like yours, Richard.

[Richard B]

apparently you didnt read carefully enough:


as for the "what me worry?" comment, I read the exact same comment from an Italian who lives on the slope of Vesuvius. and that old Geezer who refused to get off of Mt. Saint Helens when it blew........people who say stuff like that are in severe denial and have no one but themselves to blame when disaster hits.

btw: developers will build in floodplains, quake zones, lava paths, forested areas.....the point is, they dont give a damn about the risks involved. They are banking on the blase attitude of buyers. Kinda like yours, Richard.
Yawn. Just trying to razzle me? How could you ever assume I am blase about buying a home? I have no idea where you plucked that idea out of your head.

I did read the article, they re-write it all the time. I know, I lived in the East Bay way back when. I just remember as a kid reading this article, obviously not the same one, but with new factoids! I'm older than you, believe me I've read them, heard them. As for the factoid you bolded, doesn't mean it's gonna happen. Likely yes, but I don't see anyone running away.

Wait a few months, they'll write an article about San Andreas or gasp Loma Prieta...but then that one did let off steam in '89. I love how in these quake articles they love to pull statistics from the 19th Century. I don't really think anything was much built with that factor.

What I liked about the old man's point is that anything can happen. He's not pinpointing it down to any one thing. You can worry all you want, not gonna change a thing. Be thankful forwhat you have now. For yes, a earthquake, fire, storm, plane falling from the sky, any disaster can destroy a home. Even kids! lol.

[irishgrl]

Yawn. Just trying to razzle me? How could you ever assume I am blase about buying a home? I have no idea where you plucked that idea out of your head.

I did read the article, they re-write it all the time. I know, I lived in the East Bay way back when. I just remember as a kid reading this article, obviously not the same one, but with new factoids! I'm older than you, believe me I've read them, heard them. As for the factoid you bolded, doesn't mean it's gonna happen. Likely yes, but I don't see anyone running away.

Wait a few months, they'll write an article about San Andreas or gasp Loma Prieta...but then that one did let off steam in '89. I love how in these quake articles they love to pull statistics from the 19th Century. I don't really think anything was much built with that factor.

What I liked about the old man's point is that anything can happen. He's not pinpointing it down to any one thing. You can worry all you want, not gonna change a thing. Be thankful forwhat you have now. For yes, a earthquake, fire, storm, plane falling from the sky, any disaster can destroy a home. Even kids! lol.


no, of course no one is running away...they are sitting tight because thats where the money is. and, as I said, people have notoriously short memories...but the FACT remains that the bay area and Sacramento valley are vulnerable because of the relatively soft soils which can shift radically. I think the point is not necessarily to worry but to be prepared. And in some cases, get the hell outa Dodge. I didnt say you were blase about buying a home, but rather your response to news of impending disaster is to basically shrug and poke fun at those who do get concerned.....

btw: Unless you're over 50, I highly doubt you're older than me. I was born in Oakland and lived in the Bay Area all my life until the mid-80's. my family is still there, in the East Bay. Im not some rube you can dismiss. I happen to have faith in science and scientists. if they tell me that a certain fault line has mega quakes every so many years, I tend to believe them. If you choose not to, thats up to you. But you show an alarming disregard for any natural phenomenon (as evidenced in your "oceans rising" thread)

[Richard B]

no, of course no one is running away...they are sitting tight because thats where the money is. and, as I said, people have notoriously short memories.
but the FACT remains that the bay area and Sacramento valley are vulnerable because of the relatively soft soils which can shift radically.

btw: Unless you're over 50, I highly doubt you're older than me. I was born in Oakland and lived in the Bay Area all my life until the mid-80's. my family is still there, in the East Bay. Im not some rube you can dismiss. I happen to have faith in science and scientists. if they tell me that a certain fault line has mega quakes every so many years, I tend to believe them. If you choose not to, thats up to you. But you show an alarming disregard for any natural phenomenon (as evidenced in your "oceans rising" thread)
What??? I was born in Oakland, officially. Lake Merrit/Merrit Hospital (now called Summit). I wasn't dismissing you, just discussing things. I don't want you to agree with me, everyone has their own thought and ideas. Just discussing (and challenging) them. Why must you be so defensive? Cause I don't say something like: yes, yes, yes to all your comments and thoughts?

FACT: Bay Area has plenty of solid rock. My family would always always do soil samples before buying their homes or building on lots. Especially when on a hill, in Lafayette/Orinda, for example. Not everything is sand and landfill. Never had any damage from quakes, especially '89. People usually do not forget, they just decide the risk is worth it.

Take the SF Marina...first to go in a major shaker, time and time again this has been proven. All sand and land fill. Does this stop multi-million dollar homes from not selling or new ones built? Hell no. Again, it is a risk people take, like everything in life. I just don't think they have amnesia. They know what they're getting into, but living there means more to them than being turned off by the pitfalls. And every place in the world, for the most part, has it's good and bad. Perhaps I'm over simplifying a bit, but you understand.

[irishgrl]

What??? I was born in Oakland, officially. Lake Merrit/Merrit Hospital (now called Summit). I wasn't dismissing you, just discussing things. I don;t want you to agree with me, everyone has their own thought and ideas. Just discussing (and challengiing) them. Why must you be so defensive? Cause I don't point something like: yes, yes, yes to all your comments and thoughts?

FACT: Bay Area has plenty of solid rock. My family would always always do soil samples before buying their homes or building on lots. Especially when on a hill, in Lafayette/Orinda, for example. Not everything is sand and landfill. Never had any damage from quakes, especially '89. People usually do not forget, they just decide the risk is worth it.

Take the SF Marina...first to go in a major shaker, time and time again this has been proven. All sand and land fill. Does this stop multi-million dollar homes from not selling or new ones built? Hell no. Again, it is a risk people take, like everything in life. I just don;t think they have amnesia. They know what they're getting into, but living there means more to them than being turned off by the pitfalls. And every place in the world, for the most part, has it's good and bad. Perhaps I'm over simplifying a bit, but you understand.

I am not saying that the Bay doesnt have solid rock but there are places as you mentioned that are landfill.
fyi: I was born Oakland Children's Hospital. My mom and brother live in El Sobrante, my sister lives in Antioch. Ive lived in Pinole, San Pablo, El Sobrante, Concord, Martinez, Antioch, Pittsburg. We've felt earthquakes there but none so big as the Loma Prieta (which btw, I was not around for). I now live in Butte County, in the mountains northeast of Chico.

at any rate, the Bay Area is riddled with fault lines (please visit the USGS link I posted in the first post) and common sense would indicate that when you are dealing with plate tectonics, sooner or later, there needs to be a release of tension (a la earthquakes) People stay for various reasons, but they know (though they push it to the back of their minds) that sooner or later they will be dealing with the aftermath of a big quake.

I notice you didnt say how old you are....LOL!

[Richard B]

I am not saying that the Bay doesnt have solid rock but there are places as you mentioned that are landfill.
fyi: I was born Oakland Children's Hospital. My mom and brother live in El Sobrante, my sister lives in Antioch. Ive lived in Pinole, San Pablo, El Sobrante, Concord, Martinez, Antioch, Pittsburg. We've felt earthquakes there but none so big as the Loma Prieta (which btw, I was not around for). I now live in Butte County, in the mountains northeast of Chico.

at any rate, the Bay Area is riddled with fault lines (please visit the USGS link I posted in the first post) and common sense would indicate that when you are dealing with plate tectonics, sooner or later, there needs to be a release of tension (a la earthquakes) People stay for various reasons, but they know (though they push it to the back of their minds) that sooner or later they will be dealing with the aftermath of a big quake.

I notice you didnt say how old you are....LOL!
Wow. You have some major roots in the SF Bay Area. I still have family and friends in San Francisco, proper (yikes one in the Marina!), Lafayette, and Danville/Blackhawk.

Yes, California is filled with faults. No doubt. Wouldn't want to live anywhere else though! So yah, I risk it.

Funny, my Grandfather came to SF from Warsaw and arrived in SF 3 weeks after the Great Quake of '06. Course he came by boat, poor boat and had no idea he would arrive under such devastation.

He loved SF. He was there once before, after the turn of the century (19th/20th) and lost much of his hearing in a Sutro Bath accident.

[irishgrl]

lost much of his hearing in a Sutro Bath accident.
Ive heard STORIES about the Sutro Baths!

[madformac]

do you realize the fault line is under my crappy old house?!



:laugh:

No, really though. I freak out pretty much every day.

It sounds a little cold but it never concerned me until I started chatting to you Ledgies in the bay area. Now it's yet another thing to give me grey hairs! :lol: Seems everytime there is a natural disaster we send out the Ledge bat light and see if the Ledgies check in (Aussie cyclone, our London bombings etc).

Where is David when you need him?

[irishgrl]

Where is David when you need him?
thats easy. he's formulating jabborwock type messages that will keep us all entertained until the next century.......maybe.

[Rickypt]

Nothing will make me move from the greatest part of the world on earth.

[David]

thats easy. he's formulating jabborwock type messages that will keep us all entertained until the next century.......maybe.I no Jabborwock!!

Here's what Susan Hough (USGS) says about the Hayward Fault:

"In the East Bay, the Hayward Fault is thought to be capable of generating earthquakes upwards of M7, & it runs through the heart of Oakland & Berkeley. Because ground motions immediately adjacent to a fault rupture are known to be especially severe, the hazard associated with the Hayward Fault is substantial because of the high population density immediately along the fault."

Hough says later on:

"Is California prepared for the many Big Ones that it ultimately will face? Relatively speaking, the answer is yes. The state's building codes & standards are among the best in the world. Yet the fact remains that California has not been tested by the worst that the earth can produce. California has not faced a Big One since the state emerged as the most populous in the nation, home to a diverse & increasingly high-tech economy."

Susan Hough's point is a good one: The last "Big One" in California was the 1906 quake, which was about a magnitude 7.8, more or less. The city of San Francisco was highly populated in 1906, but I'm not sure the surrounding region was. It certainly wasn't to the extent it is today. Bigger population generally means more casualties & more damage, obviously. (The biggest quake in California recorded history -- in 1857 -- only killed five or six people because practically nobody lived in that region yet.)

If I lived in the Bay Area (including East Bay & South Bay, with their San Andreas, Hayward, Calaveras & other faults), I'd take some steps to prepare for medium & large quakes.

San Andreas can generate much larger magnitude quakes than Hayward (remember that longer rupture equals greater magnitude), but an M6.5 to M7 is big! It will kill people & it will damage infrastructure.

I don't know whether the entire Hayward Fault is expected to unzip in a single event, though (which sounds like what happened in 1868 to generate an M6.9).

[irishgrl]

(The biggest quake in California recorded history -- in 1857 -- only killed five or six people because practically nobody lived in that region yet.)

And wasnt that the Hayward fault that produced it? The point about population leading to higher damage costs is very true. Damage COSTS are increasing with the population which is why all of these disaster issues are to be taken seriously (unlike Bush and co.). California has improved its building codes but there are plenty of old buildings that were never retrofitted.
And that poor lady in the article who has to patch and paint every year....eventually she will reach a point where her house will split in two. And you cant get earthquake insurance in some parts of CA, which I think is a shame...

[David]

And wasnt that the Hayward fault that produced it?No, that was the Fort Tejon Quake of '57 on the San Andreas. Moment magnitude derived in recent years from that is about 8.0, which is kinda too big for the Hayward Fault, as I say. The Hayward Fault isn't long enough to generate an 8. Earthquakes rupture a patch along a fault's surface. Generally speaking, the larger the rupture patch, the larger the magnitude of the earthquake. All faults are inherently limited by their length. When Hayward ruptured in 1868, the USGS says the rupture went from Agua Caliente Creek area northerly to San Leandro (http://quake.wr.usgs.gov/prepare/ncep/hayward.html) & possibly farther. This is I guess about 50 to 60 kilometers, which might be the max that any single segment of the Hayward Fault can slip. I'm really not sure--you have to read those USGS pages & read books like "Earthshaking Science" by Susan Hough. But as you can see from that USGS page, there is uncertainty among seismologists about just how big a quake the Hayward Fault can generate in one event: some of them say about Mw6.8 & some of them say possibly higher than Mw7.0 (& some in between).

But who needs an 8 or a 7.5 to be a real problem? A smaller quake is a BAD MUTHA in such a densely populated region of the state, especially if it's shallow like the Hayward. The Hayward Fault has shallow fault depths. This means that even a small quake can break windows, make chimneys fall & create serious disturbance inside home; & a medium-sized quake can kill a lot of people & rip up lots of the buildings.

If I were living in some of those colorful little towns that straddle parts of the fault, or lie adjacent to the fault zone, I'd have plenty of earthquake insurance & I'd prepare as much as possible.
The point about population leading to higher damage costs is very true. Damage COSTS are increasing with the population which is why all of these disaster issues are to be taken seriously (unlike Bush and co.). California has improved its building codes but there are plenty of old buildings that were never retrofitted.Yep, & you'd better worry if you work in a brick building, too. They can reinforce brick buildings with those angle brackets & other things, but the way you join one brick to another is with cement, & cement doesn't bend much in an earthquake.

The other day, I secured all my carnival glass to my curio shelves with that gummy stuff you stick underneath each piece. I live on a big granite mountain, so earthquakes just feel like single sharp jolts up here. I don't have to content with much duration in movement, the way people do who live on alluvium. Site response is the name of the game.

[irishgrl]

No, that was the Fort Tejon Quake of '57 on the San Andreas. Moment magnitude derived in recent years from that is about 8.0, which is kinda too big for the Hayward Fault, as I say. The Hayward Fault isn't long enough to generate an 8.

but my original article said the Hayward fault had an earthquake in 1857 that killed 5 or 6 people :shrug: I thought it was the same one?

EDIT: oops, wrong year, but right death count.......
Before San Francisco's Great Quake of 1906, on the San Andreas fault, there was the Great Quake of 1868 on the Hayward, a magnitude 6.9 rumbler that killed five people. Severe quakes have happened on the Hayward Fault every 151 years, give or take 23 years, meaning it is now into the danger zone.