The most significant seismic event in California’s history – an earthquake of 7.9 magnitude – occurred in 1857 and ruptured about 225 miles on the San Andreas Fault. That earthquake, dubbed the last “Big One,” killed two people and produced shaking that lasted between one and three minutes.
Since then, California has exploded in population and been has been rattled by many major earthquakes. But Californians have also grown familiar with the existential dread of another “Big One” looming.
Researchers have long warned there will be another massive earthquake in Southern California. They just don’t know when…