With the major 7.8- and 7.5-magnitude earthquakes that rattled Turkey and Syria on February 6, people located in seismic zones are naturally thinking about the next “big one” that’s going to hit their community.
In particular, residents of California are bracing for their next major quake. The last time a 7.8-magnitude quake hit the state was in San Francisco on April 18, 1906. The shaking was felt halfway down the coast of Northern California, from Eureka down to Salinas. In San Francisco, devastating fires swept through neighborhoods killing more than 3,000 people and destroying around 80% of the city.
Even before the 1906 earthquake, Californians in the Bay Area already knew that a major quake could happen at any moment. Less than 40 years earlier, the 1868 earthquake hit the town of Hayward, completely leveling the town, including the courthouse. So once the 1906 quake destroyed San Francisco, the government started to acknowledge that earthquakes are a serious concern in the state.
Without specific laws in place to ensure buildings are constructed to withstand violent shaking, businesses didn’t have incentives to spend the extra money doing so. Even after the 1906 quake, San Francisco tried to cover up negative publicity by describing the incident as a fire problem rather than an earthquake problem. The idea was that companies would invest in buildings in San Francisco because fires are a problem in every city.
It wasn’t until the 6.4-magnitude quake of 1933 in Long Beach that prompted lawmakers to take action. The death toll from the earthquake was 120 people, but 120 schools around the area were damaged and some were completely flattened. If kids happened to be in school at the time of the quake, the loss of life would have been much higher.
That resulted in the Field Act getting passed, requiring mason buildings to be reinforced and able to withstand higher lateral forces. Design standards were also established and only registered architects and engineers were authorized to design schools. Approval by a State Architect and periodical inspection of the construction was also part of the Act.
Building safety regulation was part of the third law to be passed following the Long Beach quake, called the Riley Act. The Garrison Act passed prior to that required schools that survived the quake to be inspected and reviewed.
UCSD shake table
Taking structural building safety to a whole new level in California is the shake table at UC San Diego. The table simulates the stress of a building’s weight and the movement of a strong earthquake. Just last year, the columns of a building were tested to buckle and bend, which could cause a building to lean or even collapse.
Structural engineers describe a consequence of a buckling column as “storey drift.” That’s when the upper stories of a multi-story building sway in an earthquake, causing the building to lean. Soon, the columns found in many buildings throughout California will be phased out due to new building codes as a result of the shake table simulations.
“Drop, cover, and hold on!”
That’s the appropriate action to take when you find yourself in an earthquake, according to federal, state, and local emergency management experts. To teach and remind kids and adults how to reduce injury from a quake, “drop, cover, and hold on” is annually practiced on Shakeout Day on October 19.
Once you feel shaking, it’s important to drop to your hands and knees, cover your neck and head with your arms and hands, and then find cover until the shaking stops. With this action, along with buildings that are earthquake-proof, California should be able to withstand the next “big one” with minimal damage and destruction.