San Andreas fault has produced far more earthquakes than previously believed, study finds

Major earthquakes along the San Andreas fault have occurred far more often than previously believed, according to a landmark study released Friday that suggests California is overdue for a huge temblor.

The long-awaited study came after scientists spent years studying the geology of the Carrizo Plain area of the San Andreas, which is about 100 miles northwest of Los Angeles.

The last massive earthquake on that part of the fault occurred in 1857. But researchers from UC Irvine and Arizona State University found that earthquakes have occurred as often as every 45 to 144 years.

That would make the region overdue for the type of catastrophic quake often referred to as "The Big One."

The finding adds weight to the view of many Southern California seismologists that the San Andreas has been in a quiet period and that a major rupture is possible.

The research, published Friday in the journal Geology, used charcoal samples to look for earthquake activity going back centuries.

"What we know is for the last 700 years, earthquakes on the southern San Andreas fault have been much more frequent than everyone thought," UCI researcher Sinan Akciz said in a statement. "Data presented here contradict previously published reports."

-- Rong-Gong Lin II

Updated, 6:21 p.m.: Study shakes up scientists' view of San Andreas fault earthquake risk

Comments

[michael g]

Ladies and gentlemen, we here in Southern California (all of Calif., in fact) live in a highly-active earthquake region. Perhaps one of the most active in the world in terms of its proximity to a major metro area. Let us just collective pray that the "Big One" doesn't come too soon, too inconveniently (Christmas/Easter/News Years, etc.) or too devastating. But, if it does come, let us also hope that our current President doesn't blame George W. Bush.

[alicia]

We're talking about earthquakes and someone brings up Obama and Bush? Why must people try to turn everything turn into a political squabble? Let us talk about earthquakes... and keep the presidents out of the conversation.

[Sergio R]

Should NOT be called THE big one but simply A big one. We should all be prepared and aware when we are affected by a severe earth quake.

[Gary C.]

Still better than dealing with a rash of tornadoes every year.

[becky b]

is there some kind of correlation between a bunch of little earthquakes, such as the ones we've been having the past couple years, as relief in comparison to an "overdue big one"??

[Mojapan]

@becky b
According to another LAT article about six weeks or so ago there seems to be some correlation between the activity we're seeing in the extreme end. Be prepared for the worse is what I say.

[Samael Wolf]

Only an idiot would make such an article political. The sad part is they are everywhere. Of course GW Bush is culpable, he didnt spent any war money on environmental disaster preparedness.

[Caity]

With all the activity with earthquakes in Haiti and South America here recently, it wouldnt surprise me if one were to hit the U.s. Whether it be California or South Carolina, either way its a scary thought. Heres to hoping that when and if it does happen, everyone comes out okay.