In recent days, Southern California has experienced one earthquake after another. A 3.6 in Ojai on May 31. Two of a similar magnitude under the East Los Angeles area of El Sereno . Another three quakes near Newport Beach and Costa Mesa .
While these quakes were far weaker than historic temblors like the 6.7 Northridge Earthquake of 1994 , which caused an estimated $20bn in damage and killed over 57 people, do they herald the arrival of the so-called Big One in a state sitting on multiple, highly active faultlines?
There’s the notorious 800-mile-long San Andreas , which runs from near the Mexico border, east past Los Angeles, then up the coast north of Sacramento.
Major quakes occur along the fault every 180 years or so, and the San Andreas hasn’t had a majorly powerful one since 1906 . The US Geological Survey estimates it has a 60 percent chance of causing a magnitude 6.7 or greater in the Los Angeles area in the next 30 years.
Of even greater concern is the Cascadia Subduction Zone, which runs from Northern California to British Columbia, Canada. It’s overdue for an even larger quake compared with historical averages.