A so-called megathrust earthquake, which occurs on subduction zones faults, could far exceed the damage produced by any quake in recorded California history. In geological time, large earthquakes are not rare. In fact, in Northern California they are quite frequent, the most recent one a 7.2 quake that hit Petrolia, south of Eureka in far northern California, in 1992. Other sites have not experienced a major earthquake in recent times, but may be overdue, experts say. Along a stretch of the San Andreas Fault near Wrightwood in Southern California, the U.S. Geological Survey has found evidence of five major earthquakes since 1450.
Geologists say the fault is overdue for a major rupture.
Another stretch of the San Andreas, near Palm Springs, has major quakes every 220 years, but hasn't had one since 1680. Nowhere is safe Living outside California provides no guarantee of safety. The largest was felt from the East Coast to the Rocky Mountains, from Canada to the Gulf of Mexico. And experts have long said that a large quake will one day strike the East Coast, where damage would be great because building codes are not designed to allow for large earthquakes. Especially troubling are the high number of buildings in low-lying areas near rivers and bays, which would be susceptible to extensive liquefaction.