The 1857 Ft. Tejon Earthquake: In Brief
Many people think that the 1906 San Francisco earthquake was the largest earthquake to strike California in historical times, but that distinction actually belongs to the shaker that rocked southern and central California on January 9, 1857, uprooting trees in the San Bernardino Mountains and causing the Kern River to flow backwards for a time. Because of the small population in the state in 1857 (perhaps 350,000 people), there were only two fatalities, one near Fort Tejon, where many buildings were destroyed.
The earthquake was strongly felt from Los Angeles to San Francisco. The rupture on the surface of the earth can still be traced to this day, extending from near Parkfield, California, to near San Bernardino, California, over a distance of roughly 225 miles. Strong shaking from the earthquake was said to last from 1 to 3 minutes.
The earthquake occurred along the San Andreas fault, the major fault in California. The latest estimate of the size of this earthquake is magnitude 7.9. An earthquake of this size will certainly recur along the San Andreas fault, with devastating results given California's population today. The average recurrence interval for this earthquake has been estimated at 140 years ± 40 years. Since it is already 144 years since the last earthquake, the next one may not be too far in the future.
Despite the size of the earthquake, it occurred far enough away that only minor damage occurred in Santa Barbara, although the earthquake was strongly felt in that city.