1933 Long Beach Earthquake

View of John Muir School on Pacific Avenue in Long Beach, California (W.L. Huber, 1933)

 Earthquake and Impact

    The Great 1933 Long Beach Earthquake occurred on March 10th at approximately 5:54pm (DOC, n.d.). The epicenter was located at 33°39.54’ N 117°58.30 ' W (Huaksson & Gross, 1991). The rupture occurred on the Newport-Inglewood fault and was right-lateral strike-slip (SCDEC, n.d.). The earthquake was not preceded by a foreshock and fortunately not followed by any kind of tidal wave or tsunami (Davis, 1934). Although the shaking only lasted around 10 seconds, there was considerable loss and damage caused. There were 120 fatalities reported, most of which occurred due to individuals running out of buildings where they were then hit by debris (DOC, n.d.). Unfortunately this earthquake also caused about $50 million dollars in damage. A considerable amount of damage was due to the fact that there was a combination of poor construction and unfavorable geological conditions (DOC, n.d.). The most notable impact that this earthquake had on the community was the impact on schools. About 120 schools were damaged and 70 were completely destroyed, meaning that 75% of the schools in the local area were impacted (DOC, n.d.). Because so many schools were destroyed in the earthquake, it required officials to reconsider the structure of schools. This led to the passage of the Field Act, which gave the State Division of Architecture the authority to approve design and supervise construction of public school (SCDEC, n.d.)

A map showing the ground shaking intensity of the 1933 Long Beach earthquake (DOC)

  

The collapse of part of Jefferson Junior High School in Long Beach (Portland Cement Association, 1933)

Mitigation and Action

    The result of several schools being destroyed opened the eyes of many to the importance of structurally sound buildings. The damage was most significant among brick buildings that were unreinforced and poorly designed (DOC, n.d.). California and many other areas learned valuable lessons that came with the results of this earthquake. With so many schools being affected, the public safety issue surrounding architecture came to the forefront. Policy-makers realized how vital it was to insure the safety of the public, and especially of children. As mentioned previously, the Field Act was passed following the earthquake. 

    The 1933 earthquake also led to consideration of human-caused natural hazards. A study from 2016 suggests that it is possible that the earthquake was induced by drilling done at Huntington Beach, and that the significant increase of earthquakes in the early twentieth century could have been associated with these practices (Hough & Page, 2016). 

    A large part of mitigation is understanding the environment and conditions in which a location is. The poor geological conditions, combined with drilling disturbing the surrounding environment, are large factors to consider when looking at the causes and consequences of the 1933 earthquake. The effects of this natural hazard could have been mitigated if individuals would have taken the time to consider their surroundings and how they might be affected by those surroundings.  

    The 1933 Long Beach Earthquake had a substantial impact on the history of dealing with earthquakes and how we can mitigate the effects of natural hazards. The following video is a glimpse into what caused policy change and the impact that this earthquake had on the Long Beach community.

  

This video shows footage of the aftermath of the Long Beach earthquake. It includes aerial footage of destroyed and damaged structures, and also shows some of the clean up that took place after the earthquake.

References

Conservation, C. D. of. (n.d.). The 1933 Long Beach earthquake. CA Department of Conservation. Retrieved September 12, 2022, from https://www.conservation.ca.gov/cgs/earthquakes/long-beach

Davis, W. M. (1934). The Long Beach Earthquake. Geographical Review, 24(1), 1–11. https://doi.org/10.2307/209491

Earthquake information. Southern California Earthquake Data Center at Caltech. (n.d.). Retrieved September 12, 2022, from https://scedc.caltech.edu/earthquake/longbeach1933.html 

Hauksson, E., & Gross , S. (1991). SOURCE PARAMETERS OF THE 1933 LONG BEACH EARTHQUAKE. Bulletin of the Seismological Society of America, 81, 81–98. 

Hough, S. & Graves, R. (2020). The 1933 Long Beach Earthquake (California, USA): Ground Motions and Rupture Scenario. Scientific Reports. 10. 10017. 10.1038/s41598-020-66299-w

    Hough, S. E., & Page, M. (2016). Potentially induced earthquakes during the early twentieth century in the Los Angeles Basin. Bulletin of the Seismological Society of America, 106(6), 2419–2435. https://doi.org/10.1785/0120160157