A new study says stress along the San Andreas Fault in Southern California has reached its highest level in 1,000 years, renewing concern about the region’s long-feared “Big One.” The fault runs about 800 miles along the boundary between the Pacific and North American plates and has produced major quakes on an average cycle of about 150 years.[1][2]
Researchers said the greatest stress is concentrated near a junction northeast of Los Angeles where two fault systems meet.[1][2] The study’s worst-case simulation, based on a magnitude 7.8 earthquake, found that major cities including Los Angeles could be hit by strong shaking for about two minutes.[2][3]
The researchers warned that such a quake could cause hundreds of deaths and as much as $1 trillion in damage.[2][3] They also said that while seismic retrofitting has continued, many homes remain vulnerable.[2][3]
Experts added that planners still need detailed preparations for the possibility of long-term outages in water service and communications if a major earthquake strikes.[2][3]
