The San Andreas is the most notorious of these faults. It runs roughly 800 miles long and produces quakes so catastrophic that there’s a 2015 action movie about it starring The Rock. The southern section of the fault generates earthquakes every 150 years on average, and considering some parts of it haven’t ruptured in more than 200 years, Southern California is overdue for a major shaking, otherwise known as “the Big One.” [...]
Scientists don’t know exactly where the Big One will hit or how large it will be when it does, but they do have some ideas: One of the most likely scenarios, according to a 2008 federal study, is a 7.8 magnitude earthquake starting at the Salton Sea and running up through Lake Hughes, on a 200 mile long section of the fault that, in parts, hasn't ruptured since 1680—almost two centuries before California became part of the United States and long before it had any major infrastructure. [...]
The death toll probably won’t be as bad as movies like San Andreas—which Benthien calls “Hollywood fantasy”—make it out to be. Scientists predict that a magnitude 7.8 earthquake along the southern San Andreas would likely kill about 2,000 people—or less than .1 percent of Southern California’s population of more than 22 million. [...]
The estimated total impact of just building damage is $33 billion, not counting the costs following a potential quake-induced fire. It’s a hefty price tag, especially considering that most Californians don’t have earthquake insurance, which is rarely included in homeowners or renters’ insurance. Just over 14 percent of homeowners and 5 percent of renters with residential insurance have an earthquake policy, which typically covers damage to belongings and personal property like furniture and the cost of relocating to either new or temporary housing, according to 2016 data from the California Earthquake Authority. (The state agency, which supplies most of the state’s earthquake insurance, doesn’t keep statistics on how many Californians don’t have residential insurance.)