LA may be spared 'horrifying' fate of the 'Big One' from San Andreas, simulation suggests

Los Angeles is at risk of a major earthquake, but new research shows that the shaking from the "Big One" may not be as catastrophic as scientists initially feared. 

A new simulation of the shaking from a magnitude 7.8 earthquake on the south San Andreas fault suggests that LA may see 50% less ground motion than previously predicted. 

That could be good news for the City of Angels, but residents (and builders) shouldn't let their guard down, researchers say — there are still many questions about the damage a large quake could wreak in the region. 

"This is only one scenario," said study co-author Te-Yang Yeh, a postdoctoral researcher at San Diego State University. 

The study has not yet undergone peer review but appears on the preprint site ESS Open Archive. The study updates computer modeling first conducted during the 2008 Great Southern California ShakeOut, a project designed to quantify the consequences of a magnitude 7.8 quake on the southern San Andreas fault, which runs 30 miles (50 kilometers) east of downtown LA. 

According to the Statewide California Earthquake Center, such a worst-case quake is expected to cause 1,800 deaths, 50,000 injuries and $200 billion in damage. 

ShakeOut predicted surprisingly dramatic ground motion in downtown LA, said Thomas Heaton, a professor emeritus of geophysics and mechanical and civil engineering at Caltech, who was not involved in the new study.