Five Odd Southern California Earthquake Facts

HOLLYWOOD - Looking up Vine Street from Hollywood Boulevard the sudden rise of the street just above Yucca St. on the hill where The Hollywood Freeway lays atop shows the not so subtle signs of The Hollywood Fault, which has been in the news lately. Recent mapping by the California Geological Survey shows the fault is what helps give Hollywood and Los Feliz its character with its hills, and while the beauty is nice some developers are none too happy with this study.

When The Hollywood Fault, or any Southern California fault, will rupture with fury again is not clear as there are no accurate ways to predict earthquakes (not to be confused with forecasting earthquakes).

Walking over and along The Hollywood Fault on Los Feliz Blvd. one wonders about earthquakes past, and thus this piece is not about unhappy developers not getting their way, or even so much The Hollywood Fault, but rather five odd, peculiar Southern California earthquake facts.


Severe freeway damage following the 1971 Sylmar Earthquake. Used under a Creative Commons license.

1 - The First Earthquake on Record

For thousands and thousands of years earthquakes, both very small and very large, have been happening in Southern California, as paleoseismology has proven, but while there were many animals and trees to feel the shaking as hills and mountains were being pushed up there were hardly many humans around. Any humans that were around never kept anything written about it, or hid their diary.

It would not be until 1769 that the first earthquake in Southern California would be recorded. Gaspar de Portola, Father Juan Crespí and a group of over 60 explorers from Spain, in the name to extend Spain's control up the Pacific Coast and establish colonies and missions (and hopefully prevent Russia and England from acquiring and taking this territory), set out from San Diego to Monterey on July 14, 1769. Maps at the time available to de Portola's group showed California extending from San Diego only to the Monterey Bay.


When California was still thought of as an island in this 1745 map of California, and so not unusual to think de Portola's group thought the soon-to-be Golden State went as far as Monterey. Used under Creative Commons license.

After about a couple weeks of walking from San Diego to current day Orange County on July 28, 1769 and setting up camp at what is now The Santa Ana River in Anaheim de Portola's group felt a very large earthquake.

This earthquake occurred around 4 p.m., and the explorers recorded many aftershocks, several of them strong, as they made their way into the San Gabriel Valley. Records kept by de Portola's group show they stopped feeling any earthquakes when they were exiting the San Fernando Valley.

Among geologists, seismologists and historians there is much debate on just how big this earthquake was and just where the epicenter was located. Given the records by the de Portola team it was believed by many in the science and historic communities this earthquake was around magnitude 6.0 and probably on The San Jacinto Fault in the Inland Empire. Part of this was based on the diaries of the de Portola team saying they felt no more earthquakes once exiting the San Fernando Valley.

The United States Geological Survey (USGS) officially lists this earthquake, the very first earthquake in a long, forever growing list of Southern California earthquakes cataloged by the USGS, as M6.0 in the Los Angeles Basin. 

The when and where of this first recorded Southern California earthquake by the USGS has been challenged by University of California-Irvine geology professor Lisa Grant. Ms. Grant has proposed that the 1769 earthquake was actually M7.3 located on the relatively unknown San Joaquin Hills Fault located between Newport Beach and Laguna Beach, which resulted in the Orange County coastline being raised by almost 11 feet.


Put together by The Southern California Earthquake Center here is a scenario of a M6.7 earthquake on The San Joaquin Hills Fault.

The video above, combined with the diaries kept by the de Portola team, shows the theory by the UCI professor to be possible as strong shaking wanes in The San Fernando Valley. One thing the debate of the 1769 earthquake has brought up is the fact that Orange County has a major earthquake fault line that is not really well known, which has brought on more studies of the fault.

The when and where of this very first recorded Southern California earthquake still fascinates geologists and seismologists. Among other reasons, figuring out the mystery of this earthquake may help further understand and clarify the nature of earthquakes in Southern California (like the existence of a major earthquake fault in Orange County).

2 - Last Large Earthquake on Record

The last large earthquake in Southern California was a M7.9 in 1857, which is commonly called The Fort Tejon Earthquake. Not only was this the largest earthquake in Southern California recorded history, but this was one the largest earthquakes ever recorded in the United States.

This was also the last time The San Andreas Fault had a major rupture in Southern California. The infamous fault line is believed to have ruptured near Parkfield and continued rupturing south to just near The Cajon Pass. In fact, this was the last time "The Big One" happened in Southern California.

Southern California was nowhere near the megalopolis it is today, and so damage was limited to scars in the Earth. There were many scares in the Earth with cracks reported in the San Gabriel Valley and in the San Bernardino area.

In some areas the shaking is believed to have lasted up to, and even over three minutes. In Downtown L.A. the shaking is believed to have lasted over a minute.

Both the USGS and disaster planners fear the impact a repeat of this earthquake would have today.

The last time the lower southern segment of the San Andreas Fault between San Bernardino to the Salton Sea ruptured is believed to have been in or around 1690.

3 - Deadliest Earthquake Ever

The earthquake was only M6.4, but the deadliest earthquake in Southern California was the March 1933 Long Beach Earthquake, which killed 120 people. Much of the death was due to the brick construction of many buildings in Long Beach and Compton.


Compton in the aftermath of the 1933 earthquake. The fallen bricks are what killed many people in this earthquake. Used under a Creative Commons license.

Many schools were badly damaged, but luckily school was out when the earthquake struck at 5:55 p.m. (which should break the myth that big earthquakes only happen in the morning). Had this earthquake occurred just a few hours earlier the death toll would have been much higher with many school children killed.

This thought disturbed and worried a lot of people, and very quickly in April 1933 the state passed The Field Act that mandated earthquake resistant construction for schools.


Jefferson Junior High School in Long Beach after the quake. Damage to schools like this throughout the area and what could have been worried parents, teachers and students alike, which led to the passage of The Field Act. Used under a Creative Commons license.

In the 1971 Sylmar Earthquake schools built after The Field Act made it through with no damage while schools built before 1933 suffered major damage.


A newsreel showing the aftermath of the 1933 earthquake.

4 - The 1933 Epicenter Was NOT in Long Beach

The deadly jolt in 1933 will forever be known as The Long Beach Earthquake, but the epicenter was not in Long Beach. Rather, the epicenter was in Newport Beach on The Newport-Inglewood Fault.

While the damage was bad in Long Beach the earthquake ended up being the most damaging and deadliest earthquake in Orange County history. Most of the death and destruction was in Santa Ana. However there was also major damage in Garden Grove and Anaheim.


Very badly damaged building in Santa Ana. Used under Creative Commons license.

Damage was so bad in downtown Santa Ana that the Santa Ana Register, which was located in downtown Santa Ana, put together their newspaper working outside of their damaged building. 

Of course this would not be the first time an epicenter would be misidentified. The Sylmar Earthquake was not in Sylmar, but the hills above Sylmar. The Northridge Earthquake was not in Northridge, but in Reseda.

5 - The Christmas Day Earthquake

If you were asleep on Christmas morning in 1899 and felt the house shake you may have thought it was Santa Claus stuck in your chimney trying to wiggle his way out. It was not Santa, but Mother Nature showing that even big earthquakes do not get the holiday off.

At 4:25 a.m. a M6.5 earthquake stuck near San Jacinto on the fault of the same name, The San Jacinto Fault.

This earthquake was felt in a very wide area waking people up in Los Angeles, San Diego and as far as Santa Barbara.

Damage was greatest in San Jacinto and Hemet with many collapsed buildings. In Riverside many chimneys were knocked down and cracks in many buildings appeared. In fact, throughout much of the then sparsely populated Inland Empire the damage reports were much the same along with shattered windows.

The earthquake was deadly at the nearby Soboba Indian Reservation, where six people were killed by falling adobe walls.

In the Earth sciences community there is a little bit of debate if whether this earthquake was larger than M6.5 and just where exactly the epicenter was located. The Southern California Earthquake Center believes the epicenter may have been ten miles south of San Jacinto.

In the end, whether an earthquake hits on Christmas morning or during an imperialistic exploration journey, it is extraordinarily important to be prepared for the next big earthquake.

Six Interesting Facts About the 1971 Sylmar Earthquake

SYLMAR - It seemed from summer 1965 until 1971 it was a chaotic time in Southern California. There were the Watts Riots, the assassination of Robert F. Kennedy at The Ambassador Hotel, Charles Manson, the Chicano Moratorium in East Los Angeles, the ongoing destruction of the original Bunker Hill, the Sunset Strip curfew riots, George Putnam not sure if he wants to work at KTLA or KTTV, massive brush fires, and of course, seemingly to top it all off, the Earth shaking below our feet.



Collapse of I-5 overpass. A similar scene would be repeated in 1994. Author unknown; photograph in public domain. 

It was on February 9, 1971, when an earthquake fault not believed to have been a threat unleashed one of the worst damaging earthquakes in modern Southern California, in what became known as The Sylmar Earthquake.


A film by The President's Office of Emergency Preparedness along with The Defense Civil Preparedness Agency, complete with early 1970s PSA dramatic music, on the 1971 earthquake.

Here are six interesting facts about The Sylmar Earthquake you may never have known about.

1 - The 1971 Earthquake Is Holding Up New Development In Hollywood

If you have been following the news concerning new proposed developments of residential and commercial high-rise buildings around the Capital Records building in Hollywood, known as the Millennium Hollywood project, you know the proposed developments are now delayed and ensnared in controversy, because of where The Hollywood Fault may or may not be, and that delay is a result of the 1971 earthquake.

How so?

The Alquist-Priolo Earthquake Fault Zoning Act is causing the holdup and controversy in Hollywood. The Alquist-Priolo Act, according to the California Geological Survey, "is to prevent the construction of buildings used for human occupancy on the surface trace of active faults."

Alquist-Priolo came to be a state law as a result of the 1971 earthquake. The 1971 earthquake showed the destructive power of extensive surface fault ruptures, which damaged many homes and buildings right atop or very near the fault-line. Lawmakers in Sacramento realized this sort of thing will be a problem in the next major earthquake with many buildings already built on or very near faults, and thus a law was created to prevent new construction on and very near earthquake fault-lines. The law also requires real estate agents to inform potential building owners that property they may be thinking of buying is built on or very near a fault-line


As dramatically illustrated in this damaged Sylmar home this is what happens when a building is built on the surface trace of an active fault after that fault ruptures. Photograph by USGS; in public domain.

Today in Hollywood private developers, the City of Los Angeles, the California Geological Survey, private geologists hired by the developers and Hollywood residents opposed to this new development, are all trying to say just where The Hollywood Fault is located. If The Hollywood Fault lays atop one of these proposed projects, as new studies show it just may be, then The Alquist-Priolo Act could prevent a new building in Hollywood from being built.

Not too long ago the California Geological Survey introduced new mapping of The Hollywood Fault. 

2 - Two Seconds Made All The Difference

The 1971 earthquake was a massive disaster resulting in collapsed freeways, destroyed homes, and way too many ruined lives. Yet, according to geologists, this disaster was only seconds away from being a really bad disaster to a historic catastrophic disaster.

One of the big stories resulting from the earthquake was the massive evacuation of 80,000 people when the lower Van Norman Dam sustained major damage. With large aftershocks occurring, including a magnitude 5.8 shortly after the mainshock, there was great fear the dam would collapse. So a mass evacuation was underway as engineers, working nearly nonstop, were able to drain part of the dam and save the day.


Severe damage of the lower Van Norman Dam following the earthquake that came perilous close to flooding part of The Valley. Photograph by USGS; in public domain.

Just how close did the Van Norman Dan come to collapsing? According to California Geology, April/May 1971, "Had shaking of the endangered reservoirs continued for 2 seconds more, it has been estimated that there would have been no time to evacuate those below."

Had the shaking gone on for those two seconds more a UCLA study claimed thousands could have been killed if the Van Norman Dam failed.

As a result of this near catastrophic event all dams in California were reevaluated and retrofitted.

The retrofitting did its job as in the Northridge Earthquake the Van Norman Dam had no serious damage.

3 - The Epicenter Was NOT in Sylmar And The Actual Size Of The Quake Really Was...?

While this event that morning in 1971 will forever be known as The Sylmar Earthquake the actual epicenter was in the San Gabriel Mountains above The Valley. Much of the spectacular and devastating damage was in the Sylmar area and "The Sylmar Earthquake" was a name the media latched onto. Much of the same happened in 1994 when it was revealed the actual epicenter was in Reseda rather than Northridge.


A powerful photograph showing the destructive, deadly force of Mother Nature. This is believed to be the I-210/I-5 interchange, and, sadly, those in Chevrolet did not survive. Author unknown; photograph in public domain.

As for the the actual size of the earthquake, well, the United States Geological Survey puts the magnitude of this earthquake at M6.6, which for all intents and purposes has been deemed the "official magnitude" of The Sylmar Earthquake. However, other institutions, such as universities and geological groups from other countries, have put this earthquake as low as M6.5, and as high as M6.7.

4 - The Charles Manson Trial Continued Just Hours After the Earthquake

On January 27. 1971, in downtown L.A. the jury in the Charles Manson trial returned verdicts of "Guilty" for Mr. Manson and three "family members" for the Tate-LaBianca murders. A few days later the penalty phase commenced, which the jury, who had been sequestered during the trial at The Ambassador Hotel, would decide if Mr. Manson and "the family members" would receive life imprisonment or the death penalty. 

On the morning the Earth shook lead prosecutor Vincent Bugliosi, as told in his bestseller book about the trial, Helter Skelter, thought members of "the family" were trying to break into his house with all the shaking and noise going on. That was not an unfounded fear as Mr. Bugliosi, the judge overseeing the trial and many other people involved in The Manson Trial received death threats, and soon had 24-hour protection during the trial.

Schools were closed for the day, as were other businesses (some of that was probably due to the fact dozens of schools and homes were severely damaged), but amazingly, and curiously, for The Manson Trial it was business as usual. What is most amazing about this is the trial was held at the historical Los Angeles County Hall of Justice building, which was deemed unsafe and essentially abandoned immediately right after the 1994 Northridge Earthquake.


While not a 1971 view of the L.A. County Hall of Justice this photograph, circa 1940, was too good to pass up. Author unknown; photograph in public domain.

The Hall of Justice has been undergoing rehabilitation for a few years, and it is expected to be brought back into service in all its glory in 2015.

5 - A Record We Hope Is Never Broken

One grim statistic of the 1971 earthquake we hope is never broken in the next major Southern California earthquake (yes, there will be a next time) is this, The Sylmar Earthquake had more deaths than the Northridge Earthquake. Thus making it the deadest earthquake in modern L.A. history.


USGS photograph of collapse of San Fernando Veterans Administration Hospital where the majority of earthquake deaths occurred. Photograph in public domain.

The deadliest earthquake in Southern California history was the 1933 Long Beach Earthquake (which actually had an epicenter in Newport Beach).

6 - David Horowitz and Tom Brokaw Were The Lone TV Voices After the Shock

During the shaking power was knocked out, and the sun was not quite out yet, which, like the Northridge Earthquake, brought much of the L.A. Basin into utter darkness. Realizing a major event had just happened, and perhaps being a bit close to the epicenter in Burbank, KNBC reporter David Horowitz (known for his Fight Back segments, and not to be confused with a political pundit of the same name) went outside the darken NBC Studios on Alameda Avenue, and sitting on nothing more than a bar-stool he just began talking about the earthquake to those viewers who's power had not been knocked out (or those watching with those big, bulky portable televisions powered by a half-dozen batteries). Being in a darken lot made for dramatic live television. Joining Mr. Horowitz shortly after he went on the air in that darken Burbank lot was then local KNBC reporter Tom Brokaw. For a time after the earthquake Mr. Horowitz and Mr. Brokaw were providing the only live television coverage of the earthquake.

Mr. Horowitz and Mr. Brokaw attributed much of their early reporting to news reports from radio stations, KFWB, KGIL and KNX.


The cover of a LP put out by KGIL, which on 1260 AM was The Valley's radio station, which featured various airchecks of their earthquake coverage on February 9. The album is in limited press and is considered a collectors item.

As odd as it may seem today given the current nature of L.A. television news (where the slightest raindrop brings on "STORM WATCH TEAM COVERAGE"), KNBC and soon thereafter KTLA, which pioneered local breaking news coverage, were really the only local television stations that had continuous coverage of the earthquake. As the Los Angeles Times noted, KNXT and KABC had intermittent updates throughout the morning, and Ralph Story carried on with his morning show as usual only mentioning the earthquake here and there. The Times also wondered where KHJ-TV, KTTV and KCOP news coverage was during this "Day of Disaster" (as the Times' banner front-page headline ran the following day) as they carried on with their usual fare of morning cartoons all while seemingly ignoring one of the biggest disasters in modern L.A. history.