Skip to comments.La Habra quake a reminder about dangerous Puente Hills fault
Posted on 03/29/2014 10:29:25 PM PDT by Kartographer
But a 7.5 quake on the Puente Hills fault could cause the fault to slip for an entire 20 seconds and the shaking could last far longer. The Puente Hills fault could be especially hazardous over a larger area because of its shape. Other local faults, like the Newport-Inglewood and Hollywood, are a collection of vertical cracks, with the most intense shaking occurring near where the fault reaches the surface. The Puente Hills is a horizontal fault, with intense shaking likely to be felt over a much larger area, roughly 25 by 15 miles. According to estimates by the USGS and Southern California Earthquake Center, a massive quake on the Puente Hills fault could kill from 3,000 to 18,000 people and cause up to $250 billion in damage. Under this worst-case scenario, people in as many as three-quarters of a million households would be left homeless. One reason for the dire forecast is that both downtown L.A. and Hollywood are packed with old, vulnerable buildings, including those made of concrete, Jones said.
(Excerpt) Read more at latimes.com ...
ShakeOut Earthquake Scenario Shaking Simulation
LOL...They must be pushing quake insurance again.. The North Ridge quake about 6.7 killed all of 50 people...
Years earlier the Loma Prieta a 6.9 killed about the 55...
And the Loma Prieta was during rush hour, on a weekday...
They explain the reasoning.
Anything is possible, the New Madrid fault could explode tomorrow...But many of these people are scare merchants, who've love the attention and job security...
Especially that Lucy Jones character...Every time there is a minor event, she hysterically runs to the cameras, loving every minute of her face time...
Real life Mad magazine stuff.
Here's Lucy in action!
Goin’ back I’m too tired to roam,
Loma Prieta my mountain home
Ah yes! Dr. Lucy Jones. I remember her giving a press conference on TV after a late night quake in L.A. with her baby in her arms. Who was the other lady seismologist? “Kate” something wasn’t it?
The term "earthquake" is startling and conjures up images of buildings toppling and people running around all helter-skelter trying to avoid falling debris.
A little hydraulic fracturing in the right places could dissipate faultline potential energy in small amounts rather than have it go all at once. That's the idea behind avalanche control. Of course the scare merchants would go even more bonkers over white male engineers actually solving the problem.
Interesting that USGS doesn’t show this fault.
I made a comment over here
Ummm...I had a thought this morning and didnt have time to look until now; check this out
Just a for what its worth, as theyve been fracking just a few hundred yards NNE of Esteli Park, right smack in between Rowland Heights & La Habra.
I wonder if Lucy Jones wasn’t one of them that approved the fracking project over a thrust fault.
Seems all to convenient, ya know?
Scroll back up and check my links.
But I doubt it has the motivation you ascribe.
-——a horizontal fault-—
Hmmm.... Horizontal fault. That means it has a dip of 0 ?
New Study Reveals the Behavior of the Puente Hills Thrust Fault
Cross-sectional diagram of the Los Angeles Basin showing the site of the newly-released study and the location of the Puente Hills thrust fault relative to downtown Los Angeles.
In 1999, a team of scientists, led by Harvard University professor John Shaw, announced the discovery of a blind thrust fault running from northern Orange County to downtown Los Angeles. Though its discovery was, in some ways, foretold by the 1987 Whittier Narrows earthquake, which ruptured a small segment of the fault, the revelation of a “new” major fault stunned many residents of the Los Angeles area. Dubbed the Puente Hills thrust fault after the highlands above the eastern end of its 25-mile (40-kilometer) length, such a large fault located directly beneath downtown and other heavily developed areas seemed ominous and threatening. At the time, however, there was no information on how much energy might be released along this newly-mapped fault, and how frequently these releases of energy — what we all know as earthquakes — might occur.
Now SCEC scientist and USC earth sciences professor James Dolan, along with USC graduate student Shari Christofferson and the Puente Hills fault’s original discoverer, John Shaw of Harvard University, have published the results of a study, supported by the USGS and SCEC, designed to answer those questions. Found in the April 4 edition of the journal Science, these results show that the Puente Hills thrust fault has experienced four major earthquakes in the past 11,000 years, and will almost certainly produce another major earthquake at some point in the future.
The good news, Dolan explained in interviews with local media, is that these findings show that it is several thousand years between devastating earthquakes on the Puente Hills fault. As just one of a few dozen major faults in and around the Los Angeles metropolitan area, it doesn’t add much to the overall seismic hazard of Los Angeles. The findings of Dolan’s group will, however, help refine the seismic hazard assessment for the area; knowing the threat is the first step in managing it. Another plus: the methods developed during this research may be applied to other, similar areas of seismic hazard that are difficult to study using more conventional methods.
James Dolan, being interviewed in SCEC’s media center on Thursday, April 3, by Channel 7 (KABC) news.
The bad news, Dolan continued, is that when the Puente Hills thrust fault ruptures in an earthquake, it tends to do so in a very big way. Evidence from the new study, the first ever to probe the behavior of the Puente Hills fault, indicates that the four past earthquakes discovered along the fault had magnitudes between MW7.2 and 7.5 — 10 to 15 times larger than the 1994 Northridge earthquake (MW6.7), the costliest earthquake disaster in U.S. history. In a magnitude 7 earthquake, not only would more energy be released, causing a larger area to experience damaging levels of shaking, but the shaking would last longer and more of the lower frequency seismic waves that affect tall buildings and other large structures would be generated.
“So, obviously, very large earthquakes this close to the high-rise district are of concern,” Dolan said.
Worrisome, too, are the changes that would result from ground uplift during such an earthquake. According to Dolan, in a single magnitude 7 earthquake along the Puente Hills thrust fault, “USC would go up a meter or two relative to the area just south of the Los Angeles Coliseum. Downtown, and everything north of USC, would also be lifted by a meter or two.” Adding to the bad news is the fact that the Puente Hills fault extends through the Los Angeles basin, a highly populated area made up of soft sediments that amplify shaking.
“This fault is in one of the worst places you could think of to put a fault of this size and geometry,” Dolan said.
Some of these sediments, however, were the key to the study released this week. The Puente Hills thrust fault is “blind” because it never breaks through at the surface, instead producing folds in the rocks above it, which may sometimes be expressed as chain of low hills, raised up by successive earthquakes along the fault below. Each year, the Los Angeles basin is squeezed a few millimeters from north to south as tectonic plates of the Earth’s crust carrying North America and part of the Pacific Ocean floor converge. This squeezing is accommodated by the many faults in and around the basin, which shift to release the energy of this compression as earthquakes.
Sediments from nearby mountains wash down into the basin and are deposited in the flood plains along rivers and streams. As a rule, these sediments are deposited horizontally. When an earthquake uplifts the ground surface, this disrupts the smooth horizontal profile of the sediments. Gradually, this disturbance is overlain with new, horizontal sediments. Eventually, another earthquake occurs, and a new co-seismic folding event bends the layers of sediment above the blind fault. As this cycle repeats over thousands of years, a record of past earthquakes in stored in the folded sediments.
At the site chosen for this study — along the San Gabriel River in the city of Bellflower, some two miles (three kilometers) above the Puente Hills fault — Dolan and his team sank 15 boreholes into the floodplain sediments. In the cores of sediment removed from each hole, they looked for evidence of folding in the sedimentary layers. Because the same layers existed in each core, they were able to connect them, creating a three-dimensional picture that revealed major displacements of the Earth’s crust. Through the use of radiocarbon age dating, they were able to estimate how long ago these displacements — the result of major earthquakes — occurred. The relative offset of the sedimentary layers provided evidence of the size of each ancient earthquake.
“What we’ve demonstrated is that, during the past 11,000 years, the Puente Hills fault has broken at least four times, generating very large earthquakes well in excess of magnitude 7, possibly as large as magnitude 7.5,” Dolan said, noting that while the last event happened during the past several thousand years, it was impossible to say exactly when.
“We are currently in a seismic lull that has lasted at least since the first Europeans arrived here more than 200 years ago,” he said, “and that can’t last forever.”
by John Marquis, SCEC
April 4, 2003
The goal is not deaths but property damage so severe as to make the region uninhabitable and thus no longer a political force
LOL. On the corollary, maybe it's the worst place to put a site for unscientific hydrocarbon development fracking. ROFLMAO. Hypocritical Californians...
‘Who knows’ why the USGS doesn’t map it on their earthquake map...this thread was the first I’d heard of the fault.
I find it highly likely that the unregulated fracking activity is likely to blame for the quake swarm, albeit with an ironic benefit to Orange County in that it’s releasing stress, but horribly ironic, hypocritical & irresponsible of a State saturated with both known & unknown ‘sleeping’ faults. Since a fault DOES exist under this fracking site, it’ll be just dumb luck if their activities didn’t cause a much, much larger one.
Fracking causes earthquakes?
Yellowstone area acting up a bit this morning.
4 earthquakes in map area
4.8 37km ENE of West Yellowstone, Montana 2014-03-30 08:34:39 UTC-04:00 6.8 km
3.1 14km NNW of Challis, Idaho 2014-03-30 07:27:36 UTC-04:00 5.0 km
3.0 35km ENE of West Yellowstone, Montana 2014-03-30 06:36:25 UTC-04:00 1.6 km
2.8 36km ENE of West Yellowstone, Montana 2014-03-30 02:23:48 UTC-04:00 1
It’s likely hydraulic fracturing in the wrong place at the wrong time could trigger a major earthquake much like shooting an avalanche control cannon improperly could trigger a major avalanche. However hydraulic fracturing is also likely an economical solution to reducing one huge earthquake into many harmless small ones. The 7 earthquakes to hit La Habra recently didn’t cause much damage or any deaths. The earthquakes are going to happen anyway. It’s better to try to manage them than let them build up to catastrophic energy levels. Hydraulic fracturing can trigger earthquakes but is not a cause of them. Banning all hydraulic fracturing will not reduce the damage potential from natural earthquakes.
We lived on the Puente Hills fault for many years, then moved to Memphis, TN sitting on the New Madrad fault...........
I like that nice orange tip.
You’re misreading me.
I’ve already made the ironic observation that the activity reduced the stresses on the fault without tragedy.
Not a word I’ve typed is anti-fracking; far from it.
However, in the most environmentally-regulated state in the nation they’ve permitted unregulated fracking for hydrocarbon resources.
Even a green Californian can’t ignore that irony...
...made worse by the fact that in their bureaucratic largesse they permitted this site to be RIGHT OVER THE fault. You can draw a straight line between the 2 biggest quakes and practically intersect the fracking site.
There is NO EVIDENCE that this hydrocarbon fracking site was placed to reduce fault stresses. That stated, the converse will likely be the result after some bright Californian journalist reads FR and gets their editor to publish a story embarrassing to the State of California.
Irony, sarcasm, facetiousness...that’s the tone of my revelations here. Make no mistake.
Forgot your sarc tag, you did. lol
No. Serious question.
Fault hopping, eh?
Well, if we didn’t have tectonics we wouldn’t be sitting here reading about it.
Ok, thanks for connecting the dots! Sometimes discoveries are made by ineptness, so we can certainly expect some new discoveries out of CA.
You are right there are plenty of scare mongers, yet I can’t help but think of all those FReeper ‘experts’ that declared Huricane Sandy was 100% a product of ‘scared mongers’.
The snowflake pictograph gives it a nice touch, probably meant for government jackboots that don't read much before they shoot.
They must be pushing quake insurance again..
I got interested in geology while still in grade school. Way back then they were talking about injecting water into faults to relieve stresses. I recall they did that in CA with some success in the 80s. I also recall that much of this 'discovery process' was the result of research into geothermal technologies, resulting in study of the then-unknown consequent effects of deep drilling & fluid injection: seismic activity. I'm struggling to find any archive that old. However, I did find this LONG list of references dating back pre-70s for some of them:
The anti-fracking camp uses anything & everything to tarnish the practice. I don't agree with the petrochemical industry's practice of injecting production-waste chemicals into old wells OR the same's use for fracking, but the knee-jerk reaction of the industry to earthquake activity in areas coincidentally siting fracking is 'we don't cause earthquakes'; the opponents naturally use any data opposing fracking to their benefit.
In the 80s, scientists began to make connections between water levels in deep water wells & seismic activity:
From the government side, a report on earthquake hazard reduction:
Not trying to shore up the 'other side', but this from 1980 is titled, 'Measuring the Risks of Waste Disposal by Deep-Well Injection':
And here's the EPA's (barf, but good analysis) take on it, citing events back to the '60s:
A report from 1993 with LOTS of citations/references
And I found a study on deep well injection & earthquake activity dating to the early 60s
This purely-defensive piece of garbage illustrates part of my point
Here's a USGS Powerpoint on the topic
Again, clarity: I am NOT anti-fracking. Much like on nuclear, I'm anti-stupid. I've already made my facetious clarifications. If you agree with the hypocrisy I've outlined here, you'll also be ROFLYAO over the State of CA siting a fracking site over a major fault. I am.
In closing, from the 1993 study:
In evaluating the seismic hazard from fluid injection projects, we encourage people to assess the magnitudes of potential earthquakes. Many injection situations are similar to those where small earthquakes may be induced, but the likely fault areas and fault slips would pose little or no hazard for most engineering applications. However, where there are concerns about the possible damage from induced seismic activity, it would be prudent to take appropriate precautions (Nicholson and Wesson, 1990; Cypser and Davis, 1993). These precautions might include evaluating the site for the potential of induced seismic hazard, and monitoring the injection site for seismic activity.Maybe Department of Oil, Gas & Geothermal's (DOGGR) Geologist should have done his/her homework...
An engineer who works with fracking in Texas says they check where fault lines are before they drill and won’t drill close to a fault line. His company is a large one in Texas drilling in multiple locations in Texas.
It has a low degree of angle. It has about 20 to 30 degrees from horizontal. Much flatter or more “horizontal” than the 45-90 degree faults we usually hear about. Here is an article with a cut away diagram.
Now, that is funny. I hadn’t thought of it like that.
“hysterically runs to the cameras”
Isn’t that the reason that journalist go into journalism?
“Look at me look at me”! They all annoy me.
Maybe (the CA) Department of Oil, Gas & Geothermal's (DOGGR) Geologist should have done his/her homework...
This is turning out to be sooooo pathetic. Perfect fit for another 'crisis'. Most people aren't aware of all the corruption in the wake of the 1906 San Francisco earthquake; CA politicians probably salivate over all the local, dinner-table conversations, relishing a nice, fat infusion of cash, continuing budget-busting practices with careless disregard for residents/civilians (oh, I know, but...pardon the metaphor, that record got broken a long, long time ago).
Having just returned, it looks like the fault's quieting down. Good thing or bad, who knows.
But the big question is, when will the first Lib step forward to take credit for 'reducing the danger to LA', albeit through bureaucratic negligence?
Are CA bureaucrats and politicians 'white-knuckling' over whether it's going to quiet down and the whole thing 'just go away quietly'???
“I’m standing out here by the fault and I can feel it coming in!!! Look out, Diz. Whoa, mama. Hold........”(dead air)
If you think about it, the most dangerous part of any drilling of anything anywhere, is human error. Now, as soon as we find perfect humans to run all that machinery, drilling will be safer. And, as soon as we find perfect humans to drive cars, many lives will be saved. As soon as we find perfect humans (Cruz is a good substitute), then we will have perfect government.
A good leader is a great start, but I don't share your optimism for 'perfect government'...what we have is what the Founders were trying to prevent. Prescience still requires assent, and our government abhors and ignores the restrictions at every turn, rather than acceding to the Constitution. (rant over)
“A good leader is a great start, but I don’t share your optimism for ‘perfect government’...what we have is what the Founders were trying to prevent. Prescience still requires assent, and our government abhors and ignores the restrictions at every turn, rather than acceding to the Constitution.”
“Perfect government” would be one that adheres to the constitution. That would happen if we had “perfect” people.
Heh. Agreed. I think that’s what I wrote.
One of my mantras:
“The human race is the only species to have bypassed natural selection.”