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Experts Say A Strong Earthquake On Puente Hills Fault Could Do More Damage Than 'The Big One'

Time to stock up on earthquake supplies (Photo by freid via the LAist Featured Photos pool on Flickr)
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Following the La Habra earthquake and its aftershocks that shook SoCal this weekend, experts are saying a sizable quake on the fault that caused it could do more damage to Los Angeles than the dreaded, so-called “Big One.”The Puente Hills thrust fault could be more dangerous to Downtown Los Angeles and its surrounding areas because it goes directly beneath the skyscrapers of L.A., as opposed to the San Andreas Fault, which sits outside of Greater Los Angeles, according to a story in the Los Angeles Times. The moderate-but-long 5.1 quake that shook us Friday night was caused by the underground fault slipping for 10 seconds; a 7.5 quake along it could cause the fault to slip for 20 seconds, resulting in much longer shaking over a 25-by-15-mile radius.

A quake like that could kill from 3,000 to 18,000 people and cause up to $250 billion in damage. By comparison, an 8.0 San Andreas quake could cause up to 1,800 deaths, since it sits more than 30 miles from densely populated Downtown L.A.

Experts paint a nightmare scenario of a strong quake on the Puente Hills fault lifting heavy objects into the air, as that happened at the epicenter of the 1989 Loma Prieta quake. According to USGS seismologist Lucy Jones, during that destructive 6.9 quake in the San Francisco Bay Area, "we found an upside-down grand piano."

"That's the type of shaking that will hit all of downtown. And everywhere from La Habra to Hollywood," she said.

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Though scientists believe the Puente Hills fault only sees a major quake every 2,500 years, they don’t know when the last one was. The fault was only recently discovered, in 1999.