It was January 8th, 1857 — 150 years ago tomorrow.
It’s the California earthquake hardly anyone has heard of - strong enough to rip 225 miles of the San Andreas Fault and make rivers run backward, but leaving nothing like the cultural scar inflicted by the San Francisco Quake of 1906.
The AP has a story on the quake’s anniversary that serves as a scary reminder of the potential we always live with out here: “Giant California earthquake of 150 years ago is little remembered”. Amazing to think that a magnitude 7.9 quake would fade from consciousness, but in a way it hasn’t — this is the Big One that everyone knows, and there’s a “30 percent to 70 percent chance a magnitude 7.5 to 7.8 quake would rupture the southern San Andreas within the next 30 years.”
The reporter takes a trip to Fort Tejon State Historical Park, which is thought to be near where the epicenter was — looks like a cool trip for the historical exhibits alone.
The effects of the quake were felt throughout California. This is from a USGS page on the Fort Tejon quake:
This earthquake occurred on the San Andreas fault, which ruptured from near Parkfield (in the Cholame Valley) almost to Wrightwood (a distance of about 300 kilometers); horizontal displacement of as much as 9 meters was observed on the Carrizo Plain….A comparison of this shock to the San Francisco earthquake, which occurred on the San Andreas fault on April 18, 1906, shows that the fault break in 1906 was longer but that the maximum and average displacements in 1857 were larger.
And this from the Southern California Earthquake Data Center:
The Fort Tejon earthquake of 1857 was one of the greatest earthquakes ever recorded in the U.S., and left an amazing surface rupture scar over 350 kilometers in length along the San Andreas fault….
As a result of the shaking, the current of the Kern River was turned upstream, and water ran four feet deep over its banks. The waters of Tulare Lake were thrown upon its shores, stranding fish miles from the original lake bed. The waters of the Mokelumne River were thrown upon its banks, reportedly leaving the bed dry in places. The Los Angeles River was reportedly flung out of its bed, too. Cracks appeared in the ground near San Bernadino [sic] and in the San Gabriel Valley. Some of the artesian wells in Santa Clara Valley ceased to flow, and others increased in output. New springs were formed near Santa Barbara and San Fernando. Ridges (moletracks) several meters wide and over a meter high were formed in several places….
As it says in the original AP story:
…a repeat of Fort Tejon in the now-populous Inland Empire region east of Los Angeles - one of the fastest-growing areas in Southern California - could kill thousands of people and cause of [sic] tens of billions of dollars in damage.
While scientists cannot predict when the next quake will strike on the San Andreas, they say the southern segment that runs from the city of San Bernardino, 60 miles east of Los Angeles, to near the Mexican border is the most likely to break, since it has been building up stress for the longest time. It hasn’t popped in three centuries.
Spare a glance over your shoulder tomorrow at the beautiful mountains visible now thanks to the winter’s cleaner air. (Gorgeous day outside. Temps in the upper 70s, low 80s. Blue skies.) And make sure your earthquake kits are up to date.
“Past offers lessons on future Big One”
The Times picks up the story today.
Scientists hope to use the anniversary of the Jan. 9, 1857, quake in a yearlong series of preparedness campaigns aimed at shoring up residences and infrastructure.
Experts also will spend the year developing detailed scenarios about what would really happen if a magnitude 7.9 temblor — the size of the Ft. Tejon quake — were to occur along a length of the San Andreas in Southern California that scientists believe is overdue for a major quake: from the Salton Sea to Lake Hughes.
To kick off that effort, seismologists, engineers and emergency preparedness experts participated in a two-day scientific meeting Monday and Tuesday at USC, which houses the Southern California Earthquake Center.
