The Quake that Renamed California “Earthquake Country”
At 5:54 p.m. on Friday, March 10th in 1933 an earthquake fault near Long Beach fractured, causing the deadliest earthquake in California history. The earth shook for about 15 seconds. 120 people died. Hundreds of brick buildings in Long Beach, Compton and Huntington Park tumbled. Oil derricks were dislodged from their foundations. And California - known for its sunshine and oranges – was dubbed “Earthquake Country. “
The Long Beach quake measured 6.4 on the Richter scale. But in actuality the scale was crude and simply maxed out. The Long Beach quake was nowhere near the huge 8.3 San Francisco quake of 1906, but it was enough to shake the image of Southern California which was experiencing one the most dramatic population surges in its history.
So what have we learned since 1933? A lot. Here’s a short list.
1. A longer more dangerous fault system. The Newport –Inglewood fault that triggered the Long Beach quake is 46 miles long. But seismologists at Scripps Institution of Oceanography in La Jolla have recently discovered it’s actually a lot longer. That’s because they have found that the Rose Canyon fault off the coast of San Diego is part of the same system. This longer fault system runs from south of San Diego to Los Angeles. Seismologist say the Newport-Inglewood/Rose Canyon fault could produce a 7.4 quake. That is more powerful than previously believed.
2. Schools require stricter standards. It was extremely fortunate that the Long Beach quake struck in the evening when children were not at school. 230 schools in Long Beach and other cities were destroyed, or damaged so badly they were not safe to use. Thirty days later, in an impressive display of responsiveness, California lawmakers passed the Field Act. This landmark law set strict building codes for all public schools, along with inspections and tests to verify proper construction. Since this law was passed not one public school in California has collapsed in an earthquake.
3. Hospitals too. In February 1971 a 6.5 quake hit the San Fernando Valley. Sixty-five people died, many of them at hospitals. The deaths happened in hospital built before the 1933 standards were in effect. Two years later the state legislature passed the Hospital Seismic Safety Act that required acute care hospitals to be built to withstand a major quake. After the Northridge quake in 1994 the law was amended to include all hospitals. Many hospitals had to be rebuilt completely to comply with the new standards. The stricter codes not only protect patients and staff, but hospitals can be used as emergency centers in the case of a major quake.
4. Old Brick Buildings are Really Dangerous. Many of the people who died in the 1933 Long Beach were killed by falling bricks as they ran out of buildings. Even as late as 2003 two women died in Paso Robles when a brick building built in 1892 collapsed. After the 1933 Long Beach quake building any new unreinforced brick structures was prohibited. But of course that left a lot of existing ones. In 1986 California required that these old building be reinforced by “seismic retrofitting.” It is up to local governments to be sure this retrofitting happens. When the 1994 Northridge quake hit, not one of the 57 fatalities came from bricks falling.
5. ‘Tuck-in parking’ is a hazardous design. We have thousands of apartment buildings that have “tuck-under” parking. If the bottom level has weak support, the upper floors collapse crushing cars and putting people at risk. But who should pay for retrofitting? In January 2016 after a lot of debate, the city of Los Angeles passed an ordinance. Landlords and tenants will split the cost 50-50. Tenants will “contribute” their half through rent increases over ten years. Work is now underway on these buildings across L.A.
Despite these improvements, scientists at Stanford University estimated that, in a worst-case scenario, a 7.0 quake on the Newport-Inglewood fault would result in 3000 to 8000 deaths and cause $220 billion in economic
losses. That‘s about 4000 times the cost of damages from the 1933 quake.
So although we have learned a lot since the Long Beach there is still a tremendous amount of preparation that’s left to be done and many more lessons to be learned.