Study: San Andreas fault overdue for quake
By ALICIA CHANG, AP Science Writer Wed Jun 21, 6:14 PM ET
LOS ANGELES - New earthquake research confirms the southern end of the San Andreas fault near Los Angeles is overdue for a Big One. The lower section of the fault has not produced a major earthquake in more than three centuries.
"The southern section of the fault is fully loaded for the next big event," said geophysicist Yuri Fialko of the Scripps Institution of Oceanography in La Jolla.
Predicting exactly when that might happen, however, is beyond scientists' ability.
The analysis was published in Thursday's issue of the journal Nature.
Experts have estimated that a quake on the southern San Andreas of magnitude-7.6 or greater could kill thousands of people in the densely populated greater Los Angeles area and cause tens of billions of dollars in damage.
It was the 800-mile San Andreas fault, which runs down California like a scar, that caused the 1906 San Francisco earthquake that led to about 3,000 deaths.
But scientists know very little about the 100-mile dormant southern segment, which slices through Southern California from San Bernardino, east of Los Angeles, to near the Mexican border.
The section last popped in 1690, producing an estimated 7.7-magnitude quake, but caused little injury or damage because hardly anyone lived there at the time.
Using satellite radar and global positioning data, Fialko measured the movement of the southern San Andreas between 1985 and 2005. Small movements along a fault can relieve strain. Calculating those subtle motions allows scientists to figure out how much strain is building up.
Fialko found that the southern end of the fault has shown little movement and that significant strain is building up. The fault's slip rate, or average annual movement, was measured to be about an inch a year — similar to previous estimates.
Surprisingly, Fialko found the two sides of the southern San Andreas behaved differently, with one side showing more flexibility than the other. This could help scientists understand potential earthquake risks, he said.
Ken Hudnut, a U.S. Geological Survey geophysicist in Pasadena, who had no role in the study, said the latest research reaffirms the need to study the mysterious southern San Andreas more closely.
In the fall, Hudnut will head a $240,000 project that would conduct tests on the southern segment to get a better idea of the threat it poses.
Well, any of you folks on the west coast are welcome to stay with me here on the east coast until the new coastline is decided upon.
.... come east.... become Phillies Fans
Ya KNOW ya wanna
Hmmm, I will come out there only if I can (in addition to my family) bring out the Raiders so I will have a "GOOD TEAM" to yell at.
Hey it wasn't my 'fault'.
Hey! I have a house not a motel!! I say let the team there, maybe they will fall into the ocean and give MY team a chance!
... and Chev? Grrrroooooaaaaaaaaaaaaaaaaaaannnnnn.
Quote:Originally Posted by nannyjo Well, any of you folks on the west coast are welcome to stay with me here on the east coast until the new coastline is decided upon. .... come east.... become Phillies Fans Ya KNOW ya wanna
I sometimes think it would be a good idea to get out of this area. Unlike those baby quakes in California, we are expecting a big one, more along the scale of the 1965 Alaska quake, or the more recent one Indonesia. Our big ones are in the 8 and 9 point range, these truly are coastline altering events... and I live right in the danger zone.
There are two volcanoes to my north (one more to the east) and three to the south (and another just over the border in Oregon). Those are far enough not to worry too much about, but should one of them go super hyper and blow a cork, all bets are off as to just how far out of their range I am. All of them are capable of blowing mass ash but usually this goes east of me.
So, yea, sometime I think it would be a good idea to get out of this area. But then I remember that in the mid-west they have tornadoes, and some of those places have big earthquakes too, and on the east coast they have hurricanes to deal with. In Texas, they get both tornadoes and hurricanes... and the threat of flooding if the sea levels rise much more.
It seems to me there is no safe place on this planet. Even if no natural earthly disasters hit your area, and you find that one relatively most safe place, a big rock could fall out of the sky.
So, I guess I will just stay where I am... there is no safe place to go. If Nature has my number and wants to call it, there is nothing to do but answer the phone. Unlike with telemarketers, politicians, poll takers, and endless charities, Nature's call is one I cannot ignore - no matter where on the Earth I am.
Oops, forgot to say, thanks for the offer though, NJ.
Well said, MACJR, VERY well said. You know, you & I think a lot alike (well, on SOME subjects). It is true, when 'your number is up, your number is up'! It won't matter where you are, what you are doing, or how you are living, if it is time to go, it is time to go!!
RANT STARTS . . . NOW
Now, I, as you all know, have M.S.. I never asked for this but there was nothing I could have done to prevent it. I am also a smoker, however, despite what people think, it will not shorten my life any further than it is already planned to last. Quitting won't make it last even a microsecond longer either (yes, I guess that makes me a 'Fatalist'). People tell me how I can live much longer if I change my ways and eat better, drink better, exercise, quit smoking, etc. That's kinda ludicrous to me ad here is why; the Big Sur Marathon runs here annually, every health addict, exercise doing, no vice having persons join to run and (by the way) look down their collective noses at my 'over the belt' waist, my M.S. caused limp, and my cigarette in my mouth. They ALWAYS tell me how much longer I will live IF I change my ways (worse than the people in my neighborhood pushing their church)! Anyway, you know that three years ago, a 32 year old, no meat eating, works out every day, runs EVERY marathon he could, with NO health problems to speak of JUST DROPPED DEAD RIGHT WHEN THE RACE STARTED!!! He didn't even get through the first mile! Autopsy showed no reason for this mans death, it was just written up as 'natural causes' and it was dropped there.
Was this man happy when he died? I don't know, I never met him. What I DO know is I was once a runner, never marathons, but a few 10ks if I felt like it and I know I was happy when I ran. But, I am happy now without running. I did once try a very 'healthy' diet with lots of veggies and granola and no sugar, know what? That was the most UNhappy year of my life! No, I just lied, the MOST unhappy year was my FIRST marriage, but THIS came a close second!
I guess what I am saying is simple; IF you live in fear of things you cannot control, you are not living. When you accept what cards are dealt to you, make the changes that keep YOU happy (or at least content), you will find however long you have to live, will seem a good length and you will be remembered as a good person rather than a fearful person scared of his/her own shadow.
I have said this before, if you are smiling, things are easier to take and the 'bad' times seem to go by quickly. If, however, you frown at everything, 'bad' things become worse and those things go on forever and ever!
I couldn't agree with you more Walt. When your number is up..... it's up and there's nothing you can do about it. I see too many people who work so hard at doing things others have told them to do that they don't truly know what they want or how to get it. Life is too short. And if you live it without feeling it, what's the point?
I keep thinking about the song that says, "Live life like you were dying" and it gives you a whole new perspective. If I found out I only had six months to live would I do anything differently? Hell yes! But in the meantime (with hopefully years ahead of me) I'm focusing more on living and doing things that work for "me". I've learned a lot from the mistakes I've made but I've lived a lot from the chances I took. If you're afraid of life you're not really living.
Jeanna BrynerLiveScience Staff WriterLiveScience.com Tue Aug 28, 9:00 AM ET
The Los Angeles Basin and the Mojave Desert might be seismically linked, and that could explain why the urban region has experienced a 1,000-year lull in quakes while the desert has been quite active.
This claim from a new study might come as a surprise to L.A. residents, who have been shaken by the 1994 Northridge quake, the Whittier quake in 1987 and numerous other temblors big and small.
But even the Northridge quake, the costliest natural disaster in U.S. history at the time, was “a drop in the bucket” compared with the massive jolts expected during high seismic activity, said researcher James Dolan of the University of Southern California.
Dolan and his colleagues studied the geological record going back 12,000 years, focusing on the urban fault network under the Los Angeles metropolitan area and the eastern California shear zone in the Mojave Desert. The network does not include the San Andreas Fault, which has triggered 10 "big ones" during the current lull.
The scientists found several clusters of seismic “bursts” separated by periods of relative calm lasting about 1,500 to 2,000 years.
They also noted a strong geographic pattern. “When we’re having earthquakes in L.A., generally we don’t have as many earthquakes in the Mojave,” and vice versa, Dolan said.
During the current L.A. lull, the Mojave region has experienced major earthquakes, each packing 20 times the energy of the Northridge quake.
Share the load
The scientists speculate the seismic link involves some "sharing the load."
"Nature is very much like a 14-year-old boy; it's sloppy and lazy," Dolan told LiveScience. "In this case, the key thing is it's lazy. It's trying to do as little work as possible in order to get the load imposed upon it done."
As the Pacific and North American tectonic plates move past each other, the two fault systems alternate between taking on more or less of the load.
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