Monday, August 23, 2010

Scientists Discover Major Oversite in San Andreas Fault Earthquake Frequency

Southern Californians should be getting real nervous since a new study released shows scientists way underestimated the frequency of major earthquakes on the San Andreas Fault.  Previously they had predicted a pattern of the largest earthquakes occurring every 250-450 years at the fault section 100 miles from Los Angeles.  In fact, the last major earthquake near the Carrizo Plain area was in 1857.  
"The new study used more sophisticated methods in discovering former earthquakes.  Scientists dug deep trenches and used carbon dating and sophisticated imaging technology known as lidar to find signs of earth movements.  The results were stunning as scientists were able to confirm earthquakes dating back to the 15th Century, creating a far more complete record then previously known." - LA Times

The new research proved earlier scientific observations badly underestimated the number of major earthquakes.  In a nutshell, what this all means is that an earthquake is long overdue by over 150 years. 
"Thomas Jordan, director of the Southern California Earthquake Center, said the fault is 'locked and loaded. It's been a long time since an earthquake has occurred on that fault — over 150 years.'" - LA Times
The San Andreas fault is considered one of the most dangerous in Southern California, partly because it is so long that its southern section is capable of producing a temblor as large as magnitude 8.1.

As a San Franciscan, I must ask, an 8.1 earthquake as the largest?  Is that all?  Some scientists claim a 10.0 earthquake is possible in San Francisco which would flatten it like a pancake in a blink of an eye.