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Remembering The San Fernando Earthquake 50 Years Later

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San Fernando Earthquake Sylmar Earthquake
Photo Courtesy of the USGS

Five decades later, the San Fernando Earthquake has had a lasting impact on the Southland and across the nation. 

In the early morning of Feb. 9, 1971, the magnitude-6.6 quake, also known as the Sylmar Earthquake, struck the San Fernando Valley, according to the United States Geological Survey (USGS).

The seismic event caused over $500 million in property damage and 65 deaths. Most of the deaths occurred when the Veteran’s Administration Hospital collapsed. Several other hospitals, including the Olive View Community Hospital in Sylmar, suffered severe damage, according to the USGS.

Newly constructed freeway overpasses also collapsed, in damage scenes similar to those which occurred 23 years later in the 1994 Northridge Earthquake. Loss of life could have been much greater had the earthquake struck at a busier time of day. 

Photo Courtesy of the USGS

The quake occurred on the San Fernando fault zone, a zone of thrust faulting which broke the surface in the Sylmar-San Fernando Area. The total surface rupture was roughly 12 miles long, according to the geological survey.

The 1971 Sylmar Earthquake was the worst to hit an urban area of California since the 1933 magnitude-6.4 Long Beach quake, according to the USGS.

The quake prompted Governor Ronald Reagan to declare Los Angeles County a disaster area and President Richard Nixon to send Vice President Spiro Agnew to inspect the area.  

After the earthquake, the State of California enacted the Alquist Priolo Act to limit construction along faults that likely caused earthquakes able to rupture the ground surface in the last 11,000 years. 

On the federal level, Congress renewed its interest in earthquake safety, held hearings and introduced new bills to establish a national earthquake research program. 

Congress eventually passed the Earthquake Hazards Reduction Act of 1977, which led to the National Earthquake Hazards Reduction Program, or NEHRP, and was pivotal in helping establish what is now the USGS Earthquake Hazards Program. 

An earthquake large enough to spur legislative action and help form new federal programs garnered much media attention. 

The earthquake was the first disaster in the United States to happen after the Disaster Relief Act of 1970, which directed federal agencies to provide assistance to state and local governments, according to the USGS.

At the time of the earthquake, FEMA did not exist.  

The epicenter of the quake was about 8.7 miles north of San Fernando in a sparsely populated area of the San Gabriel Mountains. It was 5.6 miles deep and generally felt over approximately 80,000 square miles of California, Nevada and Arizona, according to the agency.

More than 200 aftershocks with a magnitude of 3 or more occurred over the next month. The upper San Fernando Valley, including the northern section of the City of Los Angeles, sustained the most severe damage to buildings and utilities. 

There were 64 causalities directly related to the earthquake, with 49 people killed at the San Fernando Veterans Administration Hospital. Two of its buildings were completely destroyed by the quake. Others died at Olive View Hospital, under collapsed freeway overpasses and at other locations. At Olive View, four 5-story wings pulled away from the main building and three of them toppled, according to the USGS.

“I remember biking on the [not yet open] 210 freeway and seeing damaged bridges including near Foothill Boulevard, which had mushroomed columns,” said Glenn Biasi, a USGS scientist.

Biasi’s home in Sunland, about 11 miles from the epicenter, was damaged in the earthquake. He also recalled seeing people during the recovery phase salvaging used lumber from destroyed homes in San Fernando. 

Margaret Vinci, manager of the Office of Earthquake Programs at the California Institute of Technology, was living in Arcadia, about 30 miles from Sylmar, at the time of the earthquake and although her home had no damage, her relatives in the San Fernando Valley really struggled with repairs. “It took them months to recover,” Vinci said. She recalled her aunt’s home in Reseda was so damaged that her aunt had to live with Vinci immediately after the quake. “Her front yard was a plot of mud for weeks because of broken pipes,” Vinci said. 

There were more than 250 strong-motion seismographs around Southern California at the time of the San Fernando earthquake. Most of them were privately owned but maintained by the then-Seismological Field Survey unit of the National Oceanic and Atmospheric Administration’s National Ocean Survey as part of a cooperative network.  

The San Fernando earthquake was the first to record more than 1-g of acceleration in a horizontal direction, which happened on a seismograph at the abutment of Pacoima Dam. Before that point, the maximum thought reasonable was much lower. Since then, many higher recordings have been made, but in the history of strong-motion seismology, San Fernando was a turning point, according to the USGS.

During the quake, the mountains lurched as much as 5 feet to the south in a matter of seconds, damaging roadways, pipelines and other structures embedded in the ground, and leaving a discontinuous tear where the fault ruptured the ground surface across the mountain front.  

Severe ground fractures and land sliding caused extensive damage in areas away from the fault itself, which is a common phenomenon for earthquakes of this magnitude. Landslides on very gentle slopes, known as lateral spreads and related to a process called liquefaction, happened in swaths of the northwestern San Fernando Valley. Though less visually dramatic, these caused significant damage to pipes and other infrastructure, according to the USGS.

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Earthquake

Preliminary 3.4 El Segundo Earthquake Felt Across Southland

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El Segundo Earthquake Los Angeles

A preliminary 3.4 earthquake in El Segundo was felt across the Los Angeles Region Wednesday evening.

The earthquake occurred at about 5:10 p.m. approximately 2.5 miles northeast of El Segundo, according to the United States Geological Survey (USGS).

There have been no immediate reports of injuries or damage due to the quake.

Los Angeles International Airport (LAX) crews are checking the airfield and facilities as a precaution, according to airport officials.

Residents as far as Santa Clarita reported feeling the shaking, according to the USGS.

Two smaller aftershocks were reported near Marina Del Dey and El Segundo within 30 minutes of the main quake.

Note: This is a breaking news story, more information will be added as it becomes available. 

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Lennox Earthquake Rocks Southern California

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Lennox Earthquake Southern California QuAKE

A preliminary 4.0 magnitude Lennox earthquake has rocked Southern California early Monday morning. 

The quake was reported at about 4:44 a.m. Monday just outside Lennox near Inglewood, according to the United States Geological Survey (USGS).

Dr. Lucy Jones, one of the leading seismologists in the country, said the earthquake was “very deep,” about 20 kilometers below the surface.

“Would have been felt by most people awake in L.A.,” Jones said on Twitter. “Movement was thrust, probably not on any mapped fault.”

About 30 minutes prior to the 4.0 earthquake, a 3.3 magnitude tremor occurred near the same area, according to the USGS.

A cluster of smaller aftershocks followed the main quake, ranging in size from about 2.4 to 1.6 magnitude, according to the geological survey.

The shaking was felt in the San Fernando Valley and across the Southland, according to researchers. 

Residents over 60 miles away in Palmdale even felt the earthquake, according to the USGS map.

No damage or injuries were immediately reported.

To report feeling the earthquake, visit the USGS site here.

Note: This is a breaking news story, more information will be added as it becomes available.

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3.0 Simi Valley Earthquake Felt In San Fernando Valley

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Simi Valley Earthquake -2
Photo Courtesy of the USGS

A 3.0 magnitude Simi Valley earthquake was felt in parts of the San Fernando Valley Friday afternoon.

The small earthquake was reported at 12:51 p.m. Friday centered about 6 miles west of Chatsworth near Simi Valley, according to the United States Geological Survey (USGS).

The Simi Valley quake was originally believed to be a 3.2 on the Richter scale, however, USGS seismologists later downgraded the earthquake to a 3.0 magnitude.

Residents in Canoga Park, Chatsworth, Winnetka and other areas of the west San Fernando Valley reported feeling the shake. 

The earthquake was described as a “short jolt” by some residents, with USGS reporting the quake to be over 10 kilometers deep. 

No damage or injuries have been reported as of 1 p.m. Friday. 

To report feeling the shaking of the Simi Valley earthquake, visit the USGS website.

Note: This is a breaking news story, more information will be added as it becomes available.

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