Posted on 04/14/2008 10:54:28 AM PDT by NormsRevenge
California - land of sun, beaches and earthquakes - faces an almost certain risk of being rocked by a strong temblor by 2037, scientists said Monday in the first statewide forecast of the seismic threat.
New calculations reveal there is a 99.7 percent chance a magnitude 6.7 quake or larger will hit the Golden State in the next 30 years. The odds of such an event are higher in Southern California than Northern California, 97 percent versus 93 percent.
The last time a jolt this size rattled California was the 1994 Northridge disaster, which killed 72 people, injured more than 9,000 and caused $25 billion in damage.
"It basically guarantees it's going to happen," said Ned Field, a seismologist with the U.S. Geological Survey in Pasadena and lead author of the report.
Despite the new results, scientists still cannot predict exactly where in the state such a quake will occur or when. But they say it should be a wake-up call for residents to prepare for a natural disaster in earthquake country.
"A big earthquake can happen tomorrow or it can happen 10 years from now," said Tom Jordan, director of the Southern California Earthquake Center at the University of Southern California, who was part of the research.
California is one of the most seismically active regions in the world. More than 300 faults crisscross the state, which sits atop two of Earth's major tectonic plates, the Pacific and North American plates. About 10,000 quakes each year rattle Southern California alone, although most of them are too small to be felt.
Knowing the likelihood of a strong earthquake is the first step in allowing scientists to draw up hazard maps that show the severity of ground shaking to an area. The information can also help with updating building codes and emergency plans and setting earthquake insurance rates.
The latest analysis is the first comprehensive effort by the USGS, SCEC and California Geological Survey to calculate earthquake probabilities for the entire state using newly available data. Previous quake probabilities focused on specific regions and used various methodologies that made it difficult to compare.
In the study, researchers computed the likelihood of a fault rupture using new information about where past quakes have struck, location of hard-to-spot faults and their slip rates as well as satellite-based GPS data of the Earth's crustal movement.
Scientists determined a Northridge-size shock occurs on average once every five years. The chance of a temblor that size striking the Los Angeles Basin is 67 percent compared to 63 percent for the San Francisco Bay Area. The San Francisco figure is similar to a 2003 analysis that put the probability at 62 percent. There is no past comparison that exists for Los Angeles.
Given California's seismic history, the new results should come as no surprise, said David Schwartz, a USGS geologist in Menlo Park who was not part of the study.
Researchers also calculated the statewide probabilities for larger temblors over the same time period. Among their findings: There is a 94 percent chance of a magnitude 7 shock or higher; a 46 percent chance of a magnitude 7.5 and a 4.5 percent chance of a magnitude 8.
Of all the faults in the state, the southern San Andreas, which runs from Parkfield to the Salton Sea, appears most primed to break, scientists found. There is a 59 percent chance in the next three decades that a Northridge-size quake will occur on the fault compared to 21 percent for the northern section.
The northern San Andreas produced the 1906 San Francisco earthquake, a recent disaster in geologic time compared to the southernmost segment, which has not popped in more than three centuries.
Scientists are also concerned about the Hayward and San Jacinto faults, which have a 31 percent chance of producing a Northridge-size temblor in the next 30 years. The Hayward fault runs through densely populated cities in the San Francisco Bay Area. The San Jacinto fault bisects the fast-growing city of San Bernardino.
I’ve been through 3 over 7 in the Los Angeles area and several in the 6.5 range.
6.5 is no big deal.
If these so called scientests would quit trying to study fault movement they might learn something, the fault movement is the result of an earthquake.
A volcanic explosion deep underground which causess a vertical upheavel and a wave action radiating outward in all directions is the cause.
There is no horizontal movement in an earthquake.
The fault movement is caused by the vertical vave moveme t that releases the built up stresses in the plate movement and allows it to move and relieve the built up stresses.
I’ve done the repair work on a lot of buildi gs after the 3 major quakes and all major damage is done to the walls that are parellel to the epicenter, the walls perpendicular to the epicenter sustain minor or no damage.
The major damage is done to buildings on soft ground where the wave is unhindered rollong through the building lifting and droping sections in succession. On granit or hard rock formations the wave is dampened and damage is minor.
Depending on where it hits, a 7.0 earthquake can be very minor. I was in Vegas when i believe was a 7.0 earth quake hit between Vegas and LA. Woke us up, but I no one was injured. Now if it is centered much closer to a populated area, watch out.
Thank goodness I still have my Y2K shelter.
Got my food, water, guns, generator, and satellite dish. I’m ready.
better yet,don’t tell me i have to pay for rebuilding. something unexpected,the whole country can chip in. something so obvious,they take their own chances.
More important is to first make sure you are OK with Christ! He who created the universe owns the universes. He who owns the universes makes the rules and is the ultimate judge. And His name is JESUS.
First get right with The Christ and then make sure your survival packs and supplies are OK.
I’m with ‘yawn.’ DUH.
I don't think they need any help from an earthquake destroying California, they're doing a fine job of it all on their own.
If you live in Southern California, you’ll understand why this is my favorite Site. “Clicking on a region will take you to an enlarged relief map of the area, with local faults highlighted in a variety of colors,(Then Click on THAT MAP) and linked to pages detailing information about these faults”. Last Major etc. I Love This Stuff! I mean if you live here, you might as well be aware of what’s gone on beneath you in the past.
http://www.data.scec.org/faults/faultmap.html
Earth faces a 99.997 chance of having weather tomorrow.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
I’m in West Hollywood. SO happy to not be in one of those high-rise apartments. I’m in a little house with nothing on top of me and no parking garage to be collapsed into.
All
I am probably way off center on this one but it seems to me
from the last few earthquakes I have seen in California, much of the earthquake damage was caused by resulting fires, gas pipe breaks and so on rather than the earth movement.
Since California has upped it’s earthquake restrictions and construction requirements, hopefully even less damage will occur now - but some local jurisdictions are still allowing construction on threatened land. Even weirder - people are still buying properties on that land.
OK, is it me who is math-challenged here, or the sources for this piece?
If the odds are 97% in NorCal, and 93% in SoCal, doesn't that average out to 95%???? (Not 99.7%?)
If you divide the state into Northern and Southern sections, does that leave a part not being computed here?
“Since California has upped it’s earthquake restrictions and construction requirements, hopefully even less damage will occur now”
The standards are all based on shaking and will ultimatly cause the buildings to be ripped apart because of the wave vertical movement moving through them.
1.00 - .93 = .07
.07 * .97 = .0697
.93 + .0697 = .9979
99.79%
I’m not waiting - I’ve lived through one (Loma Prieta). Felt several in the 6+ category through my life too - like the Sylmar quake back in 1970.
They are interesting events - and they can be life altering in the same way that Hurricane Katrina was life altering for people.
That being said - living in fear of something you can’t predict is just silly (and a lousy way to live your life.) Being as prepared for it as possible makes sense. Living in a stick-framed house that is bolted to the foundation makes sense.
Other than that...I’m living my life.
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