Los Angeles at risk of catostrphic quake from lesser known fault.
LA HABRA, Calif. (AP) Experts say a bigger earthquake along the lesser-known fault that gave Southern California a moderate shake could do more damage to the region than the long-dreaded "Big One" from the more famous San Andreas Fault.
The Puente Hills thrust fault, which brought Friday night's magnitude-5.1 quake centered in La Habra and well over 100 aftershocks by Sunday, stretches from northern Orange County under downtown Los Angeles into Hollywood a heavily populated swath of the Los Angeles area.
A magnitude-7.5 earthquake along that fault could prove more catastrophic than one along the San Andreas, which runs along the outskirts of metropolitan Southern California, seismologists said.
The U.S. Geological Survey estimates that such a quake along the Puente Hills fault could kill 3,000 to 18,000 people and cause up to $250 billion in damage. In contrast, a larger magnitude 8 quake along the San Andreas would cause an estimated 1,800 deaths.
http://www.sfgate.com/news/science/article/7-5-quake-on-California-fault-could-be-disastrous-5361210.php