A History of Earthquake Safety: California’s 100-year Learning Curve

California had a reputation for earthquakes long before the Great San Francisco Earthquake of 1906, yet the state’s legacy of taking action to prepare for them has been mostly a spotty pattern of starts and stops as lawmakers respond from one disaster to the next.

The state’s first “Great San Francisco Earthquake,” (before the 1906 disaster stole the menacing moniker), happened in 1868 in Hayward, destroying virtually every building in town including the county courthouse and Mission San Jose. Damage was reported along 125 miles from Santa Rosa south to Santa Cruz.[i]

A History of Earthquake Safety- California’s 100-year Learning Curve

Photo Credit to Global Earthquake Model

Nearly forty years later, the quake of 1906 wiped out much of San Francisco, but California still kept the danger under wraps: insisting that it was a one-time occurrence and assuring the public that it had nothing to worry about.

Anyone with an interest in business in the city, from real estate barons to merchants and the media, launched campaigns downplaying the damage and asserting that San Francisco was safe for investment.[ii]

The Great Cover-up

The San Francisco earthquake of 1906 was regarded as the greatest American natural disaster for nearly a century, until Hurricane Katrina in 2005. The shock waves are estimated to have been as high as a magnitude 8.3. Of the 400,000 residents of the city, over half were homeless. The ferocious shaking knocked out most gas and water lines, which created a perfect three-day storm of fires with hardly any water to extinguish them.

The devastation today is well-known. But there was a hasty effort following the event to reduce its negative publicity impact by controlling how and what information was disseminated. Reporters were asked to describe the disaster as a fire, and not an earthquake. Financial institutions would invest in a city that suffered a fire (such as Chicago in 1871, which quickly rebuilt) because all urban clusters are subject to fires, but an earthquake was a different matter – a capricious act of God that could no more be predicted than comprehended. What if San Francisco was suddenly earthquake prone? As a confidence-boosting project, the city hired writers to craft positive stories, sometimes ignoring claims of human death, and downplaying the connection and effect the earthquake had on the fires.[iii]

But despite these efforts, there were some who heeded the warning to be prepared.

According to seismologist Charles Richter, (who invented the scale upon which all earthquakes are now measured), the 1906 San Francisco earthquake moved the United States Government into acknowledging the problem.

Prior to that, no agency was specifically focused on researching earthquake activity. The United States Weather Bureau did record when they happened and several United States Geological Survey scientists had briefly disengaged from their regular duties of mapping mineral resources to write reports on the New Madrid and Charleston events, but no trained geologists were working on the problem until the Coast and Geodetic Survey was made responsible after 1906.[iv]

Eventually, the state’s first monitoring program was launched at the University of California Berkeley in 1910, with Caltech kicking off its seismological laboratory a decade later.[v]

Long Beach sparks three state laws

On March 10, 1933, a 6.4-magnitude quake in Long Beach led to 120 deaths, 500 injuries and $50 million in damage — $921 million in today’s dollars.

Untold numbers of children were spared from death or injury that day because the quake happened around dinner time. Had it struck just a few hours earlier, the more than 120 schools that were destroyed or severely damaged in the quake – facades crumbed, entire floors pancaked on top of each other – would have certainly harmed many hundreds more than the lives it did take that day.

The widespread destruction – and realization that many of Southern California’s children could have easily been killed – prompted the state of California just one month later to adopt the Field Act, which authorized a thorough architectural review of all new public schools built.

The Field Act was introduced with other laws that banned the construction of unreinforced masonry buildings, and required that earthquake forces be taken into account in structural design (specifically, a new requirement for a base shear calculation, and that school buildings must be able to withstand lateral forces equal to at least 3% of the building total mass).[vi]

The Act also established the Office of the State Architect (now Division of the State Architect or DSA) which developed design standards, quality control procedures, and required that schools be designed by registered architects and engineers. These professionals must submit their plans and specifications to the State Architect for review and approval prior to construction. The same professionals were also required by the Act to periodically inspect the construction while underway and verify that the actual work completed is in compliance with the approved drawings. Peer review was also introduced as another quality control procedure.

The Garrison Act of 1939 required reviews of existing schools built prior to the Long Beach Quake.

The third law resulting from this quake was the Riley Act, which institutionalized building safety regulation.

Such laws are essential steps for all jurisdictions wanting to dramatically reduce the loss of lives and property in future disasters. It requires that every city, county, prefecture, province, state and country should have building departments with:

Appropriately licensed professionals to review and approve construction plans and issue permits;
Qualified inspectors to ensure compliance and quality during construction;
Authority to stop improper construction and require that buildings be designed and constructed according to legally defined minimum standards;
Penalties in law for failure to comply with codes;
Comprehensive training and continuing education programs;
Organized post-disaster safety assessment programs; and
Adequate funding from fees for building permits or other sources to ensure that sufficient staff and resources will be available to effectively regulate construction.

The first test of these new laws happened in 1940, when a 6.9-magnitude quake struck the Imperial Valley. Sixteen schools build after the Field Act suffered damage at less than 1% of their value, compared to schools built before the law, which averaged damage of 29% of their value.[vii]

Alaska: 1964 vs. 2018

The largest quake ever recorded in North America, and the second largest recorded in the world, occurred on Good Friday, March 27, 1964 in Alaska. The 9.2-magnitude temblor ruptured along 600 miles of fault, moving the ground up to 60 feet as it released about 500 years of stress buildup. Yet despite its magnitude, the quake caused relatively little damage and just 131 deaths — primarily due to the state’s sparse population at the time.[viii] (The world’s largest recorded quake happened in May 1960 in Valdivia, Chile, measuring 9.5 on the Richter scale.)

In 2018, the state was walloped with another massive quake, this time measuring at 7.1 magnitude, yet the impacts — with no fatalities despite the emergence of densely populated cities — were relatively mild.

That’s because Alaska had taken deliberate steps to prepare itself after having suffered devastating earthquakes of the past. Residents there know that other major quakes will come, and stricter building codes and retrofits put into place in 1964 were instrumental in minimizing the damage and eliminating fatalities from this most recent quake.

Learning from the past

Beginning in the 1960s — following the Alaska quake — and gaining momentum in the ‘70s, a great number of laws were enacted in response to a major quake and/or anticipation of the next.

The Sylmar Quake of 1971 resulted in a flood of legislation, including:[ix]

Seismic Safety General Plan Element, requiring city and county general plans to include a seismic-safety element. (SB 351, Chapter 150, Statutes of 1971.)
Strong-Motion Instrumentation Program, requiring earthquake data-gathering instruments to be installed in large buildings and required the Division of Mines and Geology to monitor them. (SB 1374, Chapter 1152, Statutes of 1971.)
Seismic Safety of the State Capitol, requesting the state architect to evaluate the safety of the historic west wing of the Capitol and to evaluate the costs of reconstruction to meet earthquake standards. (SCR 84, Resolution Chapter 233, Statutes of 1971.)
Dam Safety Act, requiring the Office of Emergency Services and public safety officials to order dam owners to prepare emergency evacuation plans and maps of areas that would be flooded in a dam break. (SB 896, Chapter 780, Statutes of 1972.)
Hospital Seismic Safety Act of 1972, requiring specific building standards for hospitals and creating an advisory Building Safety Board. (SB 519, Chapter 1130, Statutes of 1972.)
Alquist-Priolo Earthquake Fault Zoning Act, requiring the state geologist to prepare maps of areas along major fault traces

The Sylmar quake also sparked then-Gov. Ronald Reagan in 1972 to establish the Governor’s Earthquake Council to create an executive branch of government on earthquake hazard reduction problems.

In 1975, as part of the passage of the Seismic Safety Act, the California Seismic Safety Commission was established to advise the governor, legislature and state and local governments on ways to reduce earthquake risk.

Feds start to take notice

In 1977, Congress adopted the National Earthquake Hazards Reduction Act, a law “to reduce the risks of life and property from future earthquakes in the United States through the establishment and maintenance of an effective earthquake hazards reduction program.”

By this time, it was widely accepted that earthquake-related losses could be reduced with improved construction design, and that buildings constructed prior to modern codes could be made safer with seismic retrofit construction. While changes have occurred in program details in some of the reauthorizations, the four basic NEHRP goals remain unchanged:[x]

Develop effective practices and policies for earthquake loss reduction and accelerate their implementation.
Improve techniques for reducing earthquake vulnerabilities of facilities and systems.
Improve earthquake hazards identification and risk assessment methods, and their use.
Improve the understanding of earthquakes and their effects.

Several earthquake laws were passed in the following years.

But in 1985, a new wave of legislation was sparked by the aftermath of Mexico City’s devastating 8.0-magnitude earthquake, which killed at least 5,000 people.

News of the devastation prompted Congress during the 1985-1986 session to enact several new pieces of legislation designed to make the nation’s cities safer: [xi]

SB 239 (L. Greene) created the Essential Services Building Act and declared the intent of the Legislature that essential services buildings be designed and constructed to a higher standard to resist damage from earthquakes. Established design and construction requirements
SB 547 (Alquist) created the Unreinforced Masonry Building Program affecting 286 local governments and over 25,000 buildings
SB 548 (Alquist) created the California Earthquake Hazard Reduction Act, which called for the commission to administer a program to “significantly reduce hazards by January 1, 2000.”
SB 1590 (Robbins) provided state funding for a new national research center for earthquake engineering. Unfortunately, California lost the federal competition for funds, which went to Buffalo, NY
AB 938 (Alatorre) required the Department of Conservation to develop a prototype earthquake-prediction system on the San Andreas Fault. Requires the Office of Emergency Services to develop a comprehensive emergency-response plan for shortterm earthquake predictions
AB 3249 (Katz) required private schools constructed after July 1, 1987, to have plans that meet applicable code standards. – 32 – 33 – Required their plans to be reviewed by a structural engineer, and that the project’s design professionals periodically review the construction

Loma Prieta and Northridge

On Oct. 17, 1989, during a World Series game between the San Francisco Giants and Oakland Athletics, a 6.9-magnitude earthquake caused widespread damage into Santa Cruz and Monterey counties, extending north into San Francisco and Oakland. Most notable was the collapse of a section of the double-deck Nimitz Freeway, as well as many soft-story homes built over garages. Sixty-three people died in the quake, and 3,757 people were injured. Damage was estimated at $165 million in today’s dollars.

Some 27 earthquake laws were passed in response to that quake, including the development of a National Disaster Response Plan by the NEHRP.

Southern California saw its own devastating temblor five years later with the Northridge earthquake.

The Northridge earthquake in California presented some of history’s most widely publicized images of natural destruction: the flattened Northridge Meadows apartment buildings, collapsed freeway overpasses, grotesquely twisted steel-framed parking structures and crumbling building facades.

These striking images, as horrifying as they may be, were but a fraction of the widespread devastation inflicted by the 6.7-magnitude quake.

All total, more than 6,000 commercial and industrial structures including municipal buildings, schools, universities and medical facilities were damaged on that pre-dawn morning of Jan. 17, 1994, according to the Public Policy Institute of California. Those figures include 11 hospitals, an iconic music scene venue on the Sunset strip, and the entire Northridge Fashion Center shopping mall, which as a part of reconstruction also underwent extensive cleanup of asbestos that was shaken loose during the quake.

In fact, 39% of all businesses surveyed in the Greater Los Angeles area reported suffering some sort of structural damage as a result of the quake. About a third of those cases involved damage so severe that buildings were determined to be unsafe for occupancy.

The Northridge earthquake led to a number of legislative changes. Due to the large amount lost by insurance companies, most insurance companies either stopped offering or severely restricted earthquake insurance in California. In response, the California Legislature created the California Earthquake Authority (CEA), which is a publicly managed but privately funded organization that offers minimal coverage. A substantial effort was also made to reinforce freeway bridges against seismic shaking, and a law requiring water heaters to be properly strapped was passed in 1995.[xii]

Learning from the pastWith each major earthquake comes a new understanding of the way in which buildings respond to them. Advances in the technology associated with testing systems, design and seismic modeling software, structural connections, structural forms, and seismic force resisting systems have accelerated dramatically over time.

California Governor Gavin Newsom was 22 when the 1989 Loma Prieta earthquake struck San Francisco’s Marina District, and he witnessed first-hand the devastating destruction: 64 deaths, nearly 4,000 injuries and the equivalent of $164 million in damage. Fourteen years later, he was elected mayor of the city after running on a platform that included more stringent oversight of the city building department. Making his city safer was his priority and he pushed for a mandatory seismic retrofit law that was enacted after he left office.

“This becomes essential in terms of learning from the past and making sure that we don’t make the mistakes of the past of being unprepared,” he announced in 2010 shortly after unveiling his plan.

Newsom’s advocacy was the spark that launched successive measures in cities throughout California.

Los Angeles Mayor Eric Garcetti in 2015 pushed for the nation’s most sweeping earthquake retrofit laws, requiring seismic fortification of pre-1978 wood-frame soft-story buildings and pre-1977 non-ductile concrete structures. This came on the heels of retrofit ordinances in San Francisco, Berkeley, and other cities. Since then, additional cities have adopted or are considering similar policies of their own.

The White House, in its National Security Strategy dated December 2017, listed the promotion of American resilience against natural disaster as one of the country’s primary security issues for the coming year. The National Science and Technology Council, in characterizing the elements of disaster-resilient communities, identifies as the top priority to recognize and understand the impacts of relevant hazards.

To date, more than a dozen cities have adopted laws aimed at identifying vulnerable structures and in many cases, requiring property owners to retrofit them for seismic safety. Notable among these cities are San Francisco, Los Angeles, Oakland, Beverly Hills and the County of Los Angeles.

California is also rolling out its ShakeAlert early warning system to give people time to shelter themselves moments before a major quake strikes.

But despite these efforts, there is much left to do, with thousands of buildings — 15,000 in Los Angeles alone — already identified that could likely collapse when the next major earthquake strikes.^[xiii]

Citizens care about the resilience of their communities. How much action will be taken before the next major earthquake strikes?

[i] https://en.wikipedia.org/wiki/1868_Hayward_earthquake

[ii] https://archive.org/details/californiaearthq0000gesc

[iii] https://www.cypresslawnheritagefoundation.org/blog/great-earthquake-coverup/

[iv] https://en.wikipedia.org/wiki/List_of_earthquakes_in_California#cite_note-Hough-3

[v] Ibid

[vi] Ibid

[vii] Ibid

[viii] https://en.wikipedia.org/wiki/1964_Alaska_earthquake

[ix] https://sor.senate.ca.gov/sites/sor.senate.ca.gov/files/Living%20Where%10the%20Earth%20Shakes.pdf

[x]https://training.fema.gov/hiedu/downloads/…

[xi] https://sor.senate.ca.gov/sites/sor.senate.ca.gov/files/Living%20Where%20the%20Earth%20Shakes.pdf