Tuesday, October 12, 2010

San Andreas Locked and Cocked

This is possibly the scariest report that one can read on this particular fault.  It has long been loaded and now we know it is all set to go and that one break will reasonably cause the rest of the fault to go.

Even more frightening is that the expected energy release will be ten times higher than the one that struck Haiti.  Building codes make a Haiti event eminently survivable in LA.  Ten times more is hardly survivable even for those codes for most buildings.

Of course everyone will want to argue about the risk when the first best solution is to simply not build in affected areas.  When that is not an option, then demand mandatory replacement insurance reflecting the real risk which is now sky high.  Who would have lived in the ninth ward if every building carried proper full insurance?  No insurer was quite that stupid.

I am sure today LA earthquake insurance is the best dodge contract ever written.

I personally live in Vancouver which I suspect is largely in a quake shadow of some sort and I prefer terrain intact since the last ice age for my living accommodations.  My point is that it is possible to select land cautiously to minimize risk at least.

The truth is that the San Andreas quake that is pending has quietly shifted from near term to a current real risk. We may simply not have a generation to wait.  Folks at risk are numbered in the millions and losses can be huge.  As critical, the industrial damage will eliminate a piece of the local economy.

San Andreas  fault said 'ready to go'

by Staff Writers
Los Angeles (UPI) Oct 8, 2010 

A section of the San Andreas Fault in California is overdue for a major earthquake that could reach 8.1 magnitude, researchers say.

If or when it happens, seismologists say, the earthquake could run 340 miles from Monterey in central California south to the Salton Sea, the Los Angeles Times reported.

Experts previously believed a major section of the fault 100 miles northwest of Los Angeles would remain dormant for at least another century.

But new studies suggest even that section of the fault is overdue for the "Big One," seismologist Lucy Jones said.

"All of it has plenty enough stress for it to be ready to go," Jones said. "The biggest implication of [the report] is that it increases the likelihood that when we do have a big earthquake, it will grow into the 'wall-to-wall' rupture."

The "walls" are the boundaries of the southern San Andreas, which begin at the Salton Sea and end in the town of Parkfield in Monterey County.

Seismologists generally consider the southern San Andreas Fault as a single segment because it all behaves the same -- it rarely rumbles, but when awakened, the shaking can be devastating.
The San Andreas has long been considered one of the most dangerous faults in Southern California because of its length.

Not only do longer faults produce bigger quakes, they emit a type of shaking energy that can travel longer distances.

"So a much larger area is affected by a really large earthquake," Jones said.

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